CN109645387A

CN109645387A - A kind of sweet potato leaves and stems green juice powder and preparation method thereof

Info

Publication number: CN109645387A
Application number: CN201811319349.6A
Authority: CN
Inventors: 木泰华; 罗丹; 孙红男; 陈井旺
Original assignee: Institute of Food Science and Technology of CAAS
Current assignee: Institute of Food Science and Technology of CAAS
Priority date: 2018-11-07
Filing date: 2018-11-07
Publication date: 2019-04-19

Abstract

The present invention relates to a kind of sweet potato leaves and stems green juice powders and preparation method thereof.The preparation method includes the steps that carrying out destroy the enzyme treatment to the sweet potato leaves and stems；The destroy the enzyme treatment is selected from one or more of scalding treatment, steam treatment and microwave treatment.The simple process of the method for the present invention, cost is relatively low；Food additives are not added, fully natural green is pollution-free, and shelf life of products is long, transports low with the cost of storage.Production process environmental protection, does not use organic reagent, does not discharge harmful sewage.Raw materials used abundance.Products obtained therefrom contains abundant nutrition substance, has strong antioxidant and high value pharmacological action, remains sweet potato base of leaf original color, and taste lubrication, comprehensive palatability are good, widely used, both can also be added in food as solid beverage.

Description

A kind of sweet potato leaves and stems green juice powder and preparation method thereof

Technical field

The present invention relates to a kind of preparation methods and products thereof of sweet potato leaves and stems green juice powder, belong to food processing technology field.

Background technique

Sweet potato (Ipomoea batatas Lam), belongs to Convolvulaceae Ipomoea, also known as sweet potato, pachyrhizus, red taro, sweet potato etc., It is the seventh-largest cereal crops in the whole world.It is shown according to Food and Agricultural Organization of the United Nations's data in 2016, China's sweet potato total output is about 0.71 hundred million tons, the 67% of Gross World Product is accounted for, is occupied first place in the world.Sweet potato leaves and stems are that the ground of sweet potato is overgrow part, 1 year can be more Secondary harvesting, it is suitable with the sweet potato root tuber yield of under ground portion, it is much higher than other kinds of green vegetable, there is drought resisting, Anti-Typhoon It the features such as with flood, Resistant infringement, can grow under severe conditions.Existing research shows sweet potato leaves and stems rich in protein, meals Nutrition and the functional components such as fiber, vitamin and mineral element are eaten, the average content of protein is 25.74g/100g DW, It is significantly higher than other leafy vegetables such as spinach, Chinese cabbage, three-coloured amaranth and pea seedlings, it is suitable with pigs and cattle meat and fresh milk, and Sweet Potato Leaf protein has antimicrobial and anti-diabetic characteristic, while sweet potato leaves and stems are rich in linolenic acid, palmitinic acid, linoleic acid and laurel The unsaturated fatty acids such as acid；Protein and dietary fiber content in sweet potato leaves and stems are 3 times and 5 times of sweet potato root tuber, mine respectively Material element and vitamin content are also significantly greater than sweet potato root tuber；It will be further appreciated that sweet potato leaves and stems are rich in polyphenols, Total phenol content range is 2.73~21.39g CAE/100gDW, and average content is 8.78g CAE/100gDW；Inverted efficient liquid Analysis of hplc discovery, sweet potato stem leaf polyphenol are mainly made of phenolic acid and Flavonoid substances, wherein phenolic acid master It to include caffeic acid and 7 kinds of caffeoylquinic acids, Flavonoid substances mainly include myricetin, Quercetin and rhamnetin etc.；Sweet potato Nutrition and functional component in cauline leaf is abundant, with different physiological roles, including anti-oxidant and effect of scavenging radical, drop Blood glucose, reducing blood lipid, norcholesterol effect, antitumor and immunoregulation effect, inhibiting bacteria and diminishing inflammation and antivirus action and protection liver The effects of.In conclusion sweet potato leaves and stems are a kind of quality vegetables resources for having both nutrition and functional characteristic.

No.1 Simon sweet potato is the eighties in last century from introducing China, Japan, and the kind is by domestic and international expert in clinic On practice, discovery has significant curative effect to treatment bleeding gums, hemorrhage of digestive tract, hemophilia bleeding thrombocytopenia purpura, It can also prevent the bleeding of leukaemic over the course for the treatment of, also have significant effect to treatment diabetes and ephritis, also have The functions such as antitumor, raising immune function.1988, Chinese sweet potato health care research meeting was according to 300 clinical trials over 5 years As a result, it was demonstrated that Simon No.1 has medical function, wherein blood glucose declines number up to 97.3% in 110 glycosuria cases.Perhaps Jian Hua There is certain inside and outside anti-tumor activity Deng discovery No.1 Simon sweet potato cauline leaf ethanol extract, ethyl acetate soluble group is divided into The most strong component of its anti-tumor activity.Liu Lianrui etc. has found the water solution extract of No.1 Simon sweet potato young stem and leaf to leukaemia L615 Clearly, in 40 microgram, major part leucocyte is dead, fibroblast-like cells energy normal growth for the depression effect of cell.Li Sheng The researchs such as Rong discovery Simon No.1 plays the role of promoting that megacaryocyte restores and platelet-shaped is at can treat the small meal of blood and reduce disease, warp Toxicological study and clinical observation are without obvious toxic-side effects.Can significantly it increase in Wang Fangsheng et al. discovery Simon No.1 there are two types of ingredient The differentiation of anti-sheep red blood cell (SRBC) is induced in strong Mice Body and improves coagulation antibody potency 5.17 and 1.1719 times, and the spleen of mouse Cell number and spleen weight are significantly improved.No.1 Simon sweet potato cauline leaf is indicated above with very high pharmacology value.

Since the 17th century, Japan and south east asia are just eaten sweet potato leaves and stems as green vegetable.In big portion, China Sweet potato leaves and stems are divided all to be dropped or be used as feed.In recent years, a small amount of fresh food or quick-frozen food have been developed for sweet potato leaves and stems. However processing, storage and the traffic condition of such product are subject to certain restrictions, and be easy to cause the loss to process raw material and battalion The deterioration formed point is not suitable for medium-sized and small enterprises production.Therefore, developing is suitable for medium-sized and small enterprises processing, storage and convenient transportation, and is collected The advantages that nutritive value height, strong health-care function, mouthfeel and raciness, is extremely urgent in the sweet potato leaves and stems converted products of one.Sweet potato Cauline leaf green juice powder is the powdered preparations for being process fresh sweet potato cauline leaf through processes such as drying, crushing, both can be as solid Body beverage can also be added in the food such as steamed bun, bread, cake, and purposes is extremely wide.Due to moisture content it is low (≤ 10%), microorganism is difficult to survive, and greatly reduces the cost of transport and storage etc., and shelf life of products can also significantly be prolonged It is long.It is of great significance to the development of sweet potato leaves and stems based food processing industry.

Summary of the invention

Based on above analysis, the object of the present invention is to provide the preparation methods and its production of a kind of sweet potato leaves and stems green juice powder Product, the present invention solves to be added existing for the products such as current quick-frozen sweet potato base of leaf, drying sweet potato base of leaf, Sweet Potato Leaf stem health care beverage The common problems such as work, storing be inconvenient, nutrition and functional components easily lose, and the present invention obtains that color is bud green, reconstitutes stabilization Property is good, full of nutrition, without any food additives, green and healthy sweet potato leaves and stems green juice powder product, to improve sweet potato leaves and stems The comprehensive utilization ratio of resource enriches sweet potato leaves and stems product category, promotes the sound development of sweet potato secondary industry.

The invention is realized by the following technical scheme:

A kind of preparation method of sweet potato leaves and stems green juice powder, including destroy the enzyme treatment step is carried out to the sweet potato leaves and stems；It is described Destroy the enzyme treatment is selected from one or more of scalding treatment, steam treatment and microwave treatment；The scalding treatment is will be described Sweet potato leaves and stems 2~7min of blanching in boiling water；The steam treatment is by the sweet potato leaves and stems with 100 DEG C and temperatures above 15~180s of steam blanching；The microwave treatment is by the sweet potato leaves and stems with fire processing 2 high in 800~1000W micro-wave oven ~3min.

Preparation method of the present invention, it is preferable that the destroy the enzyme treatment is steam treatment.The advantage of steam treatment is It does not make significant difference to the color of sweet potato leaves and stems, can significantly reduce the activity of peroxidase and polyphenol oxidase, and increase total phenol Content, enhancing antioxidant activity, the loss for reducing soluble component in sweet potato leaves and stems during enzyme deactivation.

Preparation method of the present invention, it is preferable that the kind of the sweet potato is Simon No.1.No.1 Simon sweet potato cauline leaf contains There are nutriment and functional components abundant, there is strong antioxidant and high value pharmacological action, analyzed through basic ingredient, the production Product contain a variety of nutrition such as albumen, polyphenol, dietary fiber, fat, mineral element and functional components, and it is daily to can make up for it people The deficiency that vegetable nutrient ingredient absorbs in life.

Preparation method of the present invention, it is preferable that the sweet potato leaves and stems are the 3-4 months sweet potato leaves and stems harvested of growth (preferably selection 5 months bottoms planted mid-August at the beginning of 6 months to the sweet potato leaves and stems harvested by the end of September).

Preparation method of the present invention, it is preferable that after Yu Suoshu destroy the enzyme treatment, include the steps that dry；It is described dry It is dry to be selected from one or more of heated-air drying, micro-wave vacuum and vacuum freeze drying；The temperature of the heated-air drying is 50~60 DEG C, the time is 12~15 hours；

The microwave power of the micro-wave vacuum is 300~350W, and vacuum degree is -0.95~-1.0MPa, temperature 40 ~50 DEG C, the time is 2~3 hours；

The step of described vacuum freeze drying include: first -39 DEG C~-45 DEG C pre-freeze 10~12 hours, then carry out true Sky is dry, and the vacuum drying temperature is -50~-56 DEG C, and vacuum degree is 40~45Pa, and the time is 72~80 hours.It is more excellent Selection of land, drying mode are vacuum freeze drying.The advantage of the vacuum freeze drying is preferably to retain in sweet potato leaves and stems Thermal sensitivity nutrition and functional component, such as total dietary fiber, vitamin, polyphenol, by the sweet potato leaves and stems of vacuum freeze drying Powder solubility with higher and its antioxidant activity retention rate highest.

Preparation method of the present invention, it is preferable that after the drying, the sweet potato leaves and stems are crushed to 80-200 Mesh.

It is preferred that being crushed with Universalpulverizer or micronizer；More preferable micronizer, it is advantageous that 95% can be made Sweet potato leaves and stems powder pass through 0.15mm (100 mesh) sieve.

Of the present invention is by cutting or whole sweet potato leaves and stems.

Preparation method of the present invention, it is preferable that including successively cleaning, drying, the enzyme deactivation to the sweet potato leaves and stems The step of processing, the drying, the crushing and packaging.

Sweet potato leaves and stems of the present invention preferably need to carry out the subsequent steps such as enzyme deactivation again by cutting or without cutting.

The present invention still further provides the sweet potato base of leaf green juice powder prepared by the above method, the sweet potato leaves and stems green juice powder The packaging bag that can choose one or more of PE, PA, AL, PET, RCPP etc. material is packed.

It is the system as described in above-mentioned any one technical solution the present invention also provides a kind of sweet potato leaves and stems green juice powder What Preparation Method was prepared, with good nutritive value.

The invention has the following advantages that

1, the simple process of the method for the present invention, cost is relatively low；Mechanization degree is high, easy to industrialized production.

2, currently preferred No.1 Simon sweet potato cauline leaf nutriment rich in and functional components have strong anti- Oxygen and high value pharmacological action, are analyzed through basic ingredient, which contains albumen, polyphenol, dietary fiber, fat, mineral member A variety of nutrition such as element and functional components can make up for it the deficiency that vegetable nutrient ingredient absorbs in people's daily life.

3, present invention preserves the original bud green colors of sweet potato base of leaf, and taste lubrication, comprehensive palatability are good when drinking, and use Way extensively, both can also be added in the food such as steamed bun, bread and cake as solid beverage.

4, sweet potato base of leaf green juice powder end prepared by the present invention beverage, storing is convenient, and water content is lower than 10%, with traditional liquid Body beverage is compared, and stability is preferable, therefore shelf life is long.

5, the present invention does not add the food additives such as sugar, thickener, preservative, and sweet potato base of leaf ingredient is 100%.

6, fully natural green of the present invention is pollution-free, and sweet potato leaves and stems raw material itself has the property of stronger bacteriostatic and disease prevention insect pest Can, without spraying insecticide in growth course, shelf life of products is long, transports low with the cost of storage.

7, production process environmental protection of the present invention, does not use any organic reagent, does not discharge any poisonous and hazardous sewage.

8, the raw materials used in the present invention, abundance, goods and materials are sufficient, moreover it is possible to solve discarded abandon of cauline leaf in sweet potato planting industry and Caused by environmental problem.

Detailed description of the invention

Fig. 1 is the basic nutrition ingredient schematic diagram of cassia lignea flour 3, osmanthus potato 10, eastern emperor's No. 1 different parts of potato；(note: A, B, C, D respectively represents the content of sweet potato different parts protein, lipid, crude fibre and ash content)；

Fig. 2 is that (note: same letter indicates that difference is gone out to influence schematic diagram of the different enzyme deactivation modes to sweet potato leaves and stems total phenol content Significant difference p < 0.05 is not present between enzyme mode)；

Fig. 3 is that (note: same letter indicates different to influence schematic diagram of the different enzyme deactivation modes to sweet potato leaves and stems antioxidant activity Significant difference p < 0.05 is not present between enzyme deactivation mode)；

Fig. 4 is the high-efficient liquid phase chromatogram (326nm) of polyphenol in the sweet potato leaves and stems of different enzyme deactivation modes；

Fig. 5 is the phase in sweet potato leaves and stems between polyphenol monomer content (mg/g, DW) and antioxidant activity (μ g TE/mg, DW) Guan Xing；A:5-CQA (R²=0.0270)；B:3-CQA (R²=0.0158)；C:4-CQA (R²=0.4554)；D:CA (R²= 0.0002)；E:4,5-CQA (R²=0.8267)；F:3,5-CQA (R²=0.7474)；G:3,4-CQA (R²=0.8148)；H: 3,4,5-CQA (R²=0.5830)；

Fig. 6 is influence schematic diagram of the different drying modes to sweet potato leaves and stems powder total phenol content and antioxidant activity；(different words Matrix shows the otherness (< 0.05) between different characteristics；HAD is heated-air drying, VFD is vacuum freeze drying, MVD is that microwave is true Empty drying, SPL are sweet potato leaves and stems；

Fig. 7 is the influence schematic diagram that different crushing mesh numbers reconstitute stability to sweet potato leaves and stems powder；

Fig. 8 is the outside drawing (storage 0 day) of the sweet potato leaves and stems green juice powder of difference storage time provided by test example 9；

Fig. 9 is the outside drawing (storage 6 months of the sweet potato leaves and stems green juice powder of difference storage time provided by test example 9 Afterwards)；

Figure 10 is the outside drawing (storage 12 months of the sweet potato leaves and stems green juice powder of difference storage time provided by test example 9 Afterwards)；

Figure 11 is the outside drawing (storage 18 months of the sweet potato leaves and stems green juice powder of difference storage time provided by test example 9 Afterwards).

Specific embodiment

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention..

Embodiment 1

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, specifically comprise the following steps:

(1) destroy the enzyme treatment: after the sweet potato leaves and stems cutting after clean drying is 1-3cm, 100 DEG C of steam blanching 120s；

(2) dry: use vacuum freeze drying, step include: first -39 DEG C pre-freeze 12 hours, then be dried in vacuo, Condition is that temperature is -56 DEG C, and vacuum degree is 45Pa, and the time is 72 hours；

(3) it crushes: Ultramicro-powder is crushed to micronizer.

Wherein, the kind of the sweet potato is Simon No.1；The cauline leaf is plantation in April, the cauline leaf of late September harvesting.

Embodiment 2

(1) 100 DEG C of steam blanching 2min of sweet potato leaves and stems after drying will destroy the enzyme treatment: be cleaned；

(2) dry: use vacuum freeze drying, step include: first -45 DEG C pre-freeze 10 hours, then carry out vacuum refrigeration Dry, condition is that temperature is -50 DEG C, and vacuum degree is 40Pa, and the time is 80 hours；

(3) it crushes: Ultramicro-powder is crushed to micronizer.

Wherein, the kind of the sweet potato is Simon No.1；The cauline leaf is plantation in April, the cauline leaf harvested by the end of August.

Embodiment 3

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: step (1) destroy the enzyme treatment: by the sweet potato leaves and stems in boiling water blanching 2min.

Embodiment 4

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: step (1) destroy the enzyme treatment: by the sweet potato leaves and stems with fire processing 2min high in 1000W micro-wave oven.

Embodiment 5

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: step (2) dry: the temperature of heated-air drying is 50 DEG C, and the time is 12 hours.

Embodiment 6

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: step (2) dry: the microwave power of micro-wave vacuum is 350W, and vacuum degree is -0.95MPa, and temperature is 40 DEG C, and the time is 2 hours.

Embodiment 7

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: step (3) crush: Universalpulverizer is crushed to 80 mesh.

Embodiment 8

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: step (3) crush: Universalpulverizer is crushed to 100 mesh.

Embodiment 9

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: described Cauline leaf is the cauline leaf that August just harvests.

Embodiment 10

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: described Cauline leaf is plantation in April, the cauline leaf of harvesting mid-August.

Embodiment 11

The present embodiment provides a kind of sweet potato leaves and stems green juice powders and preparation method thereof, and the difference with embodiment 1 is only that: (1) Destroy the enzyme treatment: the sweet potato leaves and stems after clean drying are without cutting, the blanching 2min directly in boiling water.

Comparative example 1

This comparative example provides a kind of sweet potato leaves and stems green juice powder and preparation method thereof, and the sweet potato leaves and stems are that August just harvests Sweet potato leaves and stems (kind: quotient's potato 19), it is non-divided, without any scalding treatment, 60 DEG C of heated-air dryings are used after directly cleaning 12h, Universalpulverizer are crushed to 80 mesh.Test example 1

This test example provides the nutrition and functional characteristic test of sweet potato different parts.

The whole strain sweet potato plant of cassia lignea flour 3, osmanthus potato 10, eastern emperor potato 1 are divided into leaf, stem, stalk, root tuber leading portion, block Root middle section and root tuber back segment.The nutrition of detection sweet potato different parts and functional components and antioxidant activity by the following method.

1 specific detection method

(1) measurement of protein: referring to the first method of GB 5009.5-2016；

(2) fatty measurement: referring to the second method of GB 5009.6-2016；

(3) coarse-fibred measurement: referring to GB 5009.88-2014；

(4) ash content: referring to the first method of GB 5009.4-2016；

(5) measurement of sodium: referring to the second method of GB 5009.268-2016；

(6) measurement of magnesium: referring to the second method of GB 5009.241-2017；

(7) phosphorus yield: referring to the first method of GB 5009.87-2016；

(8) measurement of potassium: referring to GB 5009.91-2017 third method；

(9) calcium catalyst: referring to GB 5009.92-2016 third method；

(10) measurement of iron: referring to the second method of GB 5009.90-2016；

(11) measurement of manganese: referring to the second method of GB 5009.242-2017；

(12) Cupper determination: referring to the 4th method of GB 5009.13-2017；

(13) Direct spectrophotometry: referring to the second method of GB 5009.14-2017；

(14) preparation of polyphenol crude extract: weighing 0.5g sweet potato leaves and stems or stem tuber powder, and 10mL is added by solid-liquid ratio 1:20 70% ethyl alcohol, under conditions of 50 DEG C, 53KHz ultrasound extraction 30min, after be centrifuged under conditions of centrifugal force 7000g 10min collects supernatant, and precipitating same procedure repeats to extract twice, merges supernatant, and 45 DEG C of rotary evaporations remove ethyl alcohol, Content is settled to 50mL with distilled water, obtains sample polyphenolic extract.

(15) measurement of total phenol content: take 0.5mL crude extract that 1.0mL 10% (v/v) forint phenol reagent is added, at 30 DEG C After keeping the temperature 30min in water-bath, 2.0mL 10% (w/v) sodium carbonate liquor is added, is uniformly mixed, continuation is kept the temperature in water-bath 30min, after immediately at 736nm measure light absorption value.Compound concentration is 0.02,0.04,0.06,0.08,0.10mg/mL Chlorogenic acid standard solution, measures light absorption value according to the method described above, establishes standard curve.

(16) 7.4mmol/L ABTS diammonium salting liquid, 2.6mmol/L K ABTS free radical scavenging ability method: are prepared₂S₂O₈ Solution.Two kinds of solution evens are mixed, 12h is kept in dark place at room temperature, generates free radicals it, ABTS is made⁺Mother liquor is used Dehydrated alcohol about dilutes 50 times, and it is 0.70 ± 0.02 that light absorption value is controlled at 734nm, obtains ABTS⁺Working solution.It takes 2.4mL ABTS is added in 0.6mL sample solution (blank control replaces sample with dehydrated alcohol)⁺Working solution is protected from light 6min reads light absorption value at 734nm immediately.Compound concentration is the ascorbic acid solution of 5,7.5,10,12.5,15 μ g/mL, is pressed Light absorption value is measured according to the above method, establishes standard curve.

(17) 40mmol/L HCl solution, 0.3mol/L ferric ion reduction activation measuring method (FRAP method): are prepared PH=3.6 acetate buffer solution, prepares 10mmol/L TPTZ solution with HCl solution, prepares 20mmol/L with acetate buffer solution FeCl3 solution.By TPTZ solution obtained, FeCl3 solution and acetate buffer solution, 1:1:10 is mixed by volume, in 37 DEG C of water-baths 30min is sufficiently reacted in pot, obtains FRAP solution.According to the difference of sample solution polyphenol content, it is diluted with distilled water.It takes 0.15mL sample solution (blank control replaces sample with distilled water), is added 2.85mL FRAP solution, and room temperature is protected from light incubation 30min, reaction terminate to measure light absorption value under 593nm wavelength immediately.Compound concentration is 10,20,50,70,100,200 μ g/mL Watermiscible vitamin E solution, measure light absorption value according to the method described above, establish standard curve.

2 measurement results

(1) the basic nutrition ingredient of sweet potato different parts

Referring to attached drawing 1, the protein in cassia lignea flour 3, osmanthus potato 10 and eastern emperor's No. 1 Sweet Potato Leaf of potato can be seen that from Fig. 1 (A) It is followed successively by leaf, stem, stalk from high to low, it is approximately sweet potato that the protein content of the leading portion of sweet potato root tuber, middle section and back segment is roughly the same The 1/6 of protein content in leaf.For cassia lignea flour 3, it is approximately 2 of content in sweet potato root tuber that stalk is suitable with the protein content of stem Times；Protein content in osmanthus potato 10 stalks and stem is roughly the same with the content in root tuber；Protein in No. 1 stem of eastern emperor's potato contains Amount is 2 times of content in stalk, is 3 times of content in root tuber.

From Fig. 1 (B) it can be seen that No. 3 lipid contents of cassia lignea flour it is highest be leaf, the lipid content in leaf is 2 of content in stem Times, it is that it is approximately content in leaf that the lipid content of the leading portion of sweet potato root tuber, middle section and back segment is roughly the same 3.5 times of content in stalk 1/4.Lipid content highest in No. 10 leaves of osmanthus potato, stem and the lipid content in stalk are roughly the same, lipid content in sweet potato root tuber Sequence from high to low is back segment, middle section, leading portion.The stem of eastern emperor's potato 1 and the lipid content of stalk are roughly the same, are higher than in leaf Lipid content, content does not have significant difference in the lipid content and leaf of sweet potato root tuber each section.

From Fig. 1 (C) it can be seen that unification is presented in the crude fiber content distribution of cassia lignea flour 3, osmanthus potato 10 and eastern emperor potato 1 Trend, i.e. crude fiber content in crude fiber content > leaf in crude fiber content > stem in stalk, the crude fibre that cassia lignea flour three contain Amount is up to 25.00g/100 gDW, and the crude fiber content at each position of sweet potato root tuber does not have significant difference, about 4g/100gDW.

From Fig. 1 (D) it can be seen that the content of ashes highest of the stem of cassia lignea flour 3, osmanthus potato 10 and eastern emperor potato 1, significantly high In the other positions of sweet potato；Secondly it is sweet potato stalk and leaf that content of ashes is higher, and the content of ashes of sweet potato root tuber is minimum, about 4g/ 100gDW, and there is no significant difference between different parts.

(2) mineral matter element of sweet potato different parts

The Mineral element content (μ g/kg, DW) of 1 sweet potato different parts of table

Continuous upper table

The regularity of distribution of the variant position Mineral Elements in Jadeite Shellfish of sweet potato as can be seen from Table 1.Sodium content in Sweet Potato Leaf Highest is significantly higher than the sodium content at the other positions of sweet potato；Content of magnesium is up to 3204.60 ± 17.81 μ g/kg in the leaf that cassia lignea flour 3, DW, content of magnesium reaches 2943.73 ± 36.22 μ g/kg, DW, content of magnesium highest in osmanthus potato 10 in the leaf of followed by eastern emperor potato 1 Position be stalk, be 2940.38 ± 182.82 μ g/kg, DW.The phosphorus content range of the different parts of the sweet potato of three kinds is 1318.69 ± 2.00~7375.88 ± 40.21 μ g/kg, DW are distributed in sweet potato leaves and stems mostly.Potassium content in Sweet Potato is significant Higher than other positions, and the high position of calcium content is then the stem of sweet potato.The leaf of sweet potato is also a good source for supplementing iron, Iron content in middle cassia lignea flour 3 is up to 1006.47 ± 131.19 μ g/kg, DW.At the same time, also containing suitable in sweet potato leaves and stems The microelements such as manganese abundant, copper, zinc.

(3) sweet potato different parts total phenol content and antioxidant activity

The total phenol content and antioxidant activity of 2 sweet potato different parts of table

It can be obtained from table 2, the highest total phenol content of three sweet potato variety different parts is leaf, and the total phenol of No. 3 leaves of cassia lignea flour contains Amount is 6.904 ± 0.245 mg CAE/g DW, and the total phenol content of No. 10 leaves of osmanthus potato is 7.718 ± 0.056mg CAE/g DW, east The total phenol content of No. 1 leaf of emperor's potato is 7.735 ± 0.041mg CAE/g DW.It is measured using ABTS free radical scavenging ability method sweet The antioxidant activity of potato different parts finds that the antioxidant activity of No. 3 sweet potato root tuber back segments of cassia lignea flour is most strong.Using ferric ion Reducing power measures the antioxidant activity of sweet potato different parts, it is found that the oxidation resistance of the leaf of three sweet potato varieties is most strong, The oxidation resistance of middle osmanthus potato 10 is up to 282.964 ± 8.128mg TE/g DW.

In conclusion by the comparative analysis of nutrition and functional components and antioxidant activity to sweet potato different parts, It was found that sweet potato leaves and stems nutrition and functional components are significantly higher than sweet potato stem tuber, it is a kind of quality vegetables resource full of nutrition.

Test example 2

This test example verifies the nutrition of different cultivars sweet potato leaves and stems and functional components and antioxidant activity.

The stem and leaf part for taking 40 sweet potato leaves and stems kind sweet potato vine top 10-15cm, clean, drain after (take part sample Product are used for the measurement of moisture content), -39 DEG C of pre-freeze 12h, -56 DEG C, 45Pa carry out 72h at vacuum freeze drying.After freeze-drying Sweet potato leaves and stems crush, cross 40 meshes, and gained cauline leaf blueness powder is placed in aluminium foil valve bag in 4 DEG C of spare (moisture contents of refrigerator storage 6.0-8.0%), the nutrition and functional components and antioxidant activity of sweet potato different parts are detected by the following method.

1 specific detection method

(1) protein, lipid, crude fibre, ash content, calcium, potassium, phosphorus, magnesium, sodium, iron, manganese, zinc, Cupper determination method are the same as test Example 1；

(2) measurement of moisture: referring to the first method of GB 5009.3-2016；

(3) measurement of energy: referring to GB/Z 21922-2008；

(4) measurement of carbohydrate: referring to GB/Z 21922-2008；

(5) preparation of polyphenol crude extract and the measurement of total phenol content: method is the same as test example 1；

(6) measurement of lead: referring to the first method of GB 5009.12-2017；

(7) measurement of chromium: referring to GB 5009.123-2014；

(8) Cadmium detrmination: referring to GB 5009.15-2014；

(7) measurement of oxidation resistance: sample is measured using supper-fast antioxidant and free radical fully-automatic analyzer O2- scavenging capacity.It is specific as follows, it is marked after above-mentioned polyphenolic extract is diluted 400 times with distilled water according to water-soluble ACW Quasi- kit specification is measured.Specifically:

Reagent 1 (R1): dilution (is directly used)；

Reagent 2 (R2): buffer (is directly used)；

Reagent 3 (R3): photosensitizer and detection agent；

Reagent 4 (R4): ascorbic acid dry powder is as standard reagent.

Solution is formulated as follows:

1) preparation (R3-WS) of 3 working solution of reagent: being added the R2 of 750 μ L after R3 is thawed, spare after vortex；

2) the R1 mixed liquor of 10 μ L dense H2SO4 and 490 μ L the preparation (R4-WS) of 4 working solution of reagent: are added to standard examination In agent bottle, it is configured to the ascorbic acid standard items stock solution (R4-SS) of 10mmol/L, is then diluted to the stock solution with R1 The ascorbic acid standard items working solution of 0.1mmol/L.

Determination step:

1) measurement of blank control: the R1,1000 μ LR2,25 μ LR3-WS of 1500 μ L, fierceness shake are sequentially added in test tube Loading to supper-fast antioxidant and free radical fully-automatic analyzer is measured immediately after swinging, and measurement item is chosen as blank, survey Determine parameter are as follows: detection time, 250s；Smoothing factor, 40；Zeroing function is opened；Correction and measurement parameter, a time lag lag- lag0；Cleaning, 1 × every measurement are primary.Replication, up to detection curve peak shape is sharp and favorable reproducibility.

2) measurement of ascorbic acid standard curve: being added 1000 μ LR2 in test tube, is separately added into 5,10,20,30,50 μ LR4-WS is settled to 2.5mL with R1 respectively, is configured to the standard solution of various concentration, is separately added into 25 μ LR3-WS, fierce Loading measures item and chooses standard, be measured according to above-mentioned condition, each concentration point repeats to analyzer immediately after concussion Measurement 3 times or more, until coefficient R 2 >=0.9900.

3) 1490 μ LR1,1000 μ LR2,10 μ L sample solution, 25 μ LR3- the measurement of sample: are sequentially added in Reagent Tube WS, loading measures item and chooses as sample, be measured according to above-mentioned condition to analyzer immediately after fierceness concussion.Sample is molten The measured value of liquid is automatically derived by instrument software, and measured value is converted into ascorbic acid, is as a result expressed as μ g ascorbic acid Equivalent (ascorbic acid, ACE)/mL sample solution.Using ascorbic acid as standard items, the O2- scavenging capacity of sample It is expressed as μ g ascorbic acid (ascobic acid equivalent, ACE)/mL.

2 measurement results

(1) basis is analyzed

The measurement result of sweet potato leaves and stems main component is shown in Table 3 and table 4.The moisture content range of 40 kind sweet potato leaves and stems is 84.09-88.92 g/100g FW, average content is 87.61 ± 1.07g/100g FW.The highest kind of moisture content is Xu's potato 053601, it is 88.92 ± 0.34 g/100g FW, it is 84.09 ± 0.81g/100g FW that the minimum kind of content, which is Soviet Union's potato 16,. Such as Chinese cabbage (about 95g/100g FW), rape (about 92g/100g FW), spinach compared with common leafy vegetable moisture content (about 91g/100g FW), leek (about 91g/100 g FW), the moisture content of sweet potato leaves and stems is relatively low.Moisture is nutritional ingredient Carrier, directly affects the physiological activity of food, but the aqueous more easy breeding microorganism of food and go bad, be unfavorable for protecting Fresh, storage and transport, therefore, comparatively sweet potato leaves and stems preservation more more resistance to than Vegetables.

The average content of crude protein is 24.14 ± 3.51g/100g DW in sweet potato leaves and stems, and the highest kind of content is food 5, For 31.08 ± 0.09 g/100g DW, it is 16.69 ± 0.09g/100g DW, separately that the minimum kind of content, which is quotient's potato 19 (spring), Outside, different cultivars sweet potato leaves and stems, the content difference of crude protein are anisotropic significant (P < 0.05).In addition it has been reported that, fresh sweet potato cauline leaf The content (2.99g/100g FW) of crude protein is higher than crude protein content (1.28-2.13g/100g FW) in sweet potato root tuber and often See the crude protein content (1.3-2.8g/100g FW) (FAIS composition table of foods, 2013) in leaf vegetables.Protein is that the mankind rely With basis for the survival nutrient, human body must constantly absorb various protein from food, just can guarantee the normal fortune of body Row.It is reported that sweet potato leaves and stems Amino Acids in Proteins rich content, only lysine slightly lacks, amino acid pattern and FAO That recommends is almost the same.Therefore, sweet potato leaves and stems can provide excellent vegetable protein for the diet of people.

Coarse-fibred average content is 11.55 ± 1.26g/100g DW (1.43g/100g FW), content in sweet potato leaves and stems Highest kind be Pu's potato 17,14.26 ± 0.38g/100g DW, the minimum kind of content be quotient's potato 19 (summer), 9.15 ± 0.49g/100g DW.Data with existing is it is found that coarse-fibred content is 1.4 times of sweet potato root tuber or so in fresh sweet potato cauline leaf 1.5-2.0 times of celery, 2-4 times of Chinese cabbage.Cellulose is one of maintenance essential substance of human health, referred to as 7th class nutrition needed by human.With promotion gastrointestinal peristalsis, enhancing digestive function, the absorption for preventing cholesterol, maintenance blood glucose Balance, to have the healthcare function for preventing and treating the diseases such as cerebrovascular sclerosis, diabetes, tumour.Therefore, sweet potato leaves and stems are The good food source of complementary diets fiber.

The highest kind of crude fat content is western agriculture No. 1,5.28 ± 0.15g/100g DW in sweet potato leaves and stems, and content is minimum Kind be Xu-shu No.22-1,2.08 ± 0.06g/100g DW, average content be 3.69 ± 0.88g/100g DW (0.46g/ 100g FW), the content difference of the sweet potato leaves and stems crude fat of different cultivars is anisotropic significant.The average content of crude fat in sweet potato leaves and stems (3.69±0.88g/100g DW；0.46g/100g FW) (0.33g/100g FW) higher than sweet potato root tuber.Lipid material it is main Function is composition biomembrane, provides energy, the solvent as liposoluble substance, and vegetable fat is mostly made of unsaturated fatty acid, Unsaturated fatty acid can reduce Blood Cholesterol and triglycerides, reduce blood viscosity, improve blood microcirculation；Improve brain The activity of cell, the various health care functions such as enhancing memory.

Sweet potato leaves and stems crude ash content is shown in Table 4, and the highest kind of content is Soviet Union's potato 14,13.72 ± 0.02g/100g DW, The minimum kind of content is Ji potato 65, and 7.39 ± 0.86g/100g DW, average content is 9.63 ± 1.78g/100g DW (1.26 ±0.26g/100g FW).The content of ash content is 0.5-1.5 times of content of ashes in celery in sweet potato leaves and stems, is the 2- of Chinese cabbage 4 times.High ash content shows that its inorganic elements total amount is high, and human nutriology has proven to a variety of inorganic elements in human life activity at present In have important physiology and pathology sense, many elements participate in the synthesis of enzymes, to promoting body metabolism, enhancing immune Power prevents disease, and performance plays an important role.

In sweet potato leaves and stems the content range of carbohydrate and gross energy be respectively 42.03-61.36g/100g DW and 375.40-438.48 kcal/100g DW, average content be respectively 51.00 ± 5.05g/100g DW and 415.34 ± 14.59kcal/g DW。

The content (g/100g DW) of 3 40 kinds of sweet potato leaves and stems moisture of table, crude protein, crude fibre, crude fat

Note: letter indicates the otherness (p < 0.05) between different cultivars；*: moisture content is in terms of fresh weight, (g/100FW)

The measurement result (g/100g DW) of the carbohydrate of 4 40 kinds of sweet potato leaves and stems of table, coarse ash, gross energy

Note: letter indicates the otherness (p < 0.05) between different cultivars；*: the measurement result of gross energy is expressed as Kcal/ 100g DW

(2) Mineral Concentrations are analyzed

Content of mineral substances measurement result in sweet potato is shown in Table 5, wherein table 5 be macroelement potassium (K), phosphorus (P), calcium (Ca), The measurement result of magnesium (Mg), sodium (Na), table 6 are the measurement result of trace elements iron (Fe), manganese (Mn), zinc (Zn), copper (Cu).

As can be seen from the results, in macroelement the content range of K element be 479.3 ± 1.0 (Beijing 553s) to 4280.6 ± 37.0 (Ji potato) mg/100 g DW；The content range of P element is 131.1 ± 3.3 (Jinyu 1s) to 2639.8 ± 1.3 (Xu's potatos 26)mg/100g DW；The content range of Ca element is 229.7 ± 0.4 (Xu-shu No.22s -1) to 1958.1 ± 24.1 (Soviet Union's potato 14) mg/ 100g DW,；The content range of Mg element is 220.2 ± 2.4 (Anhui potatos 5) to 910.5 ± 1.3 (heart is No. 1 fragrant) mg/100g DW；The content range of Na element is 8.06 ± 0.55 (simons 1) to 832.31 ± 68.84 (Ji potato) mg/100g DW.

In macroelement, highest content is K element, and average content is 1625.1mg/100g DW；Followed by P member Element, average content are 1248.2mg/100g DW；It is again Ca, average content is 744.9mg/100g DW；It is Mg member later Element, average content are 405.2mg/100g DW；It is finally Na element, average content is 159.98mg/100g DW.

The acid-base balance of the potassium element adjustable osmotic pressure for being suitable for into the cell and body fluid, participates in endocellular sugar and protein Metabolism.Help to maintain neurological health, the rhythm of the heart normal, can be pre- anti-stroke, and assist muscle normal contraction.Taking in high sodium And when leading to hypertension, potassium has hypotensive activity.Potassium element is rich in sweet potato leaves and stems, it may be said that sweet potato leaves and stems are with higher Health-care efficacy, but at present from the angle of nutrition, the nutriture value of substance is evaluated with a kind of content height of nutrient merely It is worth not comprehensive enough, potassium sodium ratio theory is in conjunction with body to the absorption equilibrium effect of potassium and sodium element, with the potassium of food, sodium content Than come the criterion of evaluating the high-quality degree of food.It is low that the high food of potassium sodium ratio is significantly larger than potassium sodium ratio to the healthy meaning of human body Food.As shown in Table 5, in the potassium sodium ratio of all kinds, Simon No.1 (520.39), Xu's potato 53 (189.73), corridor potato 9 ((81.26), Jinyu 1 (67.16), agricultural university 6-2 (65.31), food 5 (54.64), Xu's potato 55-2 (52.73) Xu's potato 038008 (49.88), corridor potato 7-12 (48.12), Soviet Union potato 14 (47.86), Ji potato 14 (47.86), Ji potato 65 (37.64), quotient's potato 19 (summer) (35.37), Ji potato 22 (34.45) Soviet Union potato 16 (34.39), Anhui potato 5 (25.21), good fortune potato 2 (23.99), it is former No. 6 close (20.08), cigarette potato 25 (19.59), river potato 294 (18.48) potassium sodium ratio be above the spinach (18.10) of the measurements such as Taira With the potassium sodium ratio of water spinach (11.56).

In this research, average content (the 405.2mg/100g DW of sweet potato leaves and stems Mg element；50.2mg/100g FW), with The report of Ishida etc. is consistent: 79mg/100g FW.Mg member procatarxis can be interacted with P, be the necessary mineral member of worthwhile synthesis Element, human body Mg shortage can cause asthma, diabetes and osteoporosis diseases.It may thus be appreciated that sweet potato leaves and stems are human body intake magnesium members The good food material of element.

As shown in table 6, by determination of trace elements result each in sweet potato leaves and stems it is found that the content range of Fe be 1.92 ± 0.00 (Xu-shu No.22-1) to 21.77 ± 0.33 (Xu-shu No.22) mg/100g DW；The content range of Mn is 1.71 ± 0.00 (Xu's potatos 22-1) to 10.92 ± 0.18 (Xu-shu No.22) mg/100g DW；The content range of Zn is to arrive in 1.20 ± 0.00 (19 spring of quotient's potato) 3.23 ± 0.04 (Xu's potato 23) mg/100g DW；The content range of Cu is 0.67 ± 0.00 (19 spring of quotient's potato) to 1.86 ± 0.25 (Ji potato) mg/100g DW.

In microelement, highest content is Fe element, and average content is 8.15mg/100g DW；It is followed successively by later Mn, average content are 4.10mg/100g DW；The average content of Zn is 2.27mg/100g DW；The average content of Cu is 1.28mg/100g DW.Although the absorption of human body utilization rate of nonheme iron is lower than the heme iron in meat, blood in plant The intake of red pigment iron can increase the risk that human body suffers from colon cancer.

Mn participates in the oxidative stress system of human body, and related with the transport of glucose homeostasis and calcium.In GB28050-2011 The NRV value for providing Mn is 3mg, and therefore, edible 73.17g DW sweet potato leaves and stems (i.e. 590.56g FW sweet potato leaves and stems) can meet The demand of human body Mn element.It is close to be higher than the content in sweet potato root tuber, with spinach for the content of Zn and Cu in sweet potato leaves and stems.Zn is The constituent of several metalloenzyme participates in the metabolism of DNA and RNA, and with signal transduction, gene expression etc. is closely related；Cu and machine The absorption of body iron is related, participates in a variety of enzyme reactions and the synthesis of collagen.

The content of several frequently seen poisonous and harmful element lead (Pb), chromium (Cr) and cadmium (Cd) is shown in Table 2.2 in sweet potato leaves and stems (B), Pb content highest in Xu's potato -22 (spring), for 1.40 ± 0.18mg/kg DW (0.17 ± 0.01mg/kg FW)；Cr content Highest kind is quotient's potato 19 (summer), is 1.40 ± 0.00mg/kg DW (0.17 ± 0.01mg/kg FW)；40 sweet potato leaves and stems The highest content of kind Cd is only 0.29 ± 0.04mg/kg DW (0.04 ± 0.00mg/kg FW)；In addition, all sweet potato varieties Arsenic element (As) is not detected.GB2762-2012, which defines fresh vegetables, common are malicious harmful element such as Pb, Cr, Cd, As Limit standard be respectively 0.1,0.5,0.05,0.5mg/kg FW.Know that Pb, Cr, Cd, As content are significant in sweet potato leaves and stems Lower than the limit standard of national standard, safety nuisance free.

The content (mg/100g DW) of macroelement in 5 40 kinds of sweet potato leaves and stems of table

The content of trace quantity mineral substance element and poisonous and harmful element in 6 40 kinds of sweet potato leaves and stems of table

Note: Pb, Cr, Cd content are expressed as mg/kg DW；"-" is to be not detected

(3) total phenol content and antioxidant activity

Sweet potato leaves and stems total phenol content is shown in Table 7, and the content range of sweet potato leaves and stems total phenol is 2.73-12.46g CAE/100g DW, average content are 7.08g CAE/100g DW, and consistent with the report such as Islam, this report points out total phenol in sweet potato leaves and stems Content range be 1.42-17.1g CAE/100g DW.The purple No. 7 total phenol content highests of Ji potato 04150 and Chongqing, respectively 12.46 ± 0.62and, 12.30 ± 0.65g CAE/100 g DW, and otherness is not significant；The total phenol content of food 5 is minimum, is 2.73±0.02g CAE/100g DW.Different cultivars sweet potato leaves and stems total phenol content is different, this may be due to sweet potato leaves and stems product Caused by kind, polyphenol oxidase activity, maturity, harvest post processing mode, storage condition, trophic component difference.

The antioxidant activity of sweet potato leaves and stems is shown in Table 7, and it is 0.80 ± 0.01mg ACE/ that purple No. 7 antioxidant activities in Chongqing are most strong Secondly mg DW eats 5 antioxygen for Ji potato 04150 and capital 6, respectively 0.73 ± 0.00 and 0.73 ± 0.01mg ACE/mg DW It is minimum to change activity, is 0.08 ± 0.01mg ACE/mg DW.Chongqing is purple No. 7 higher with Ji 04150 total phenol content of potato, and difference Not significant, the antioxidant activity of the two but has significant difference.The polyphenol of two kinds can be speculated in composition or the ratio of component Example is upper, and there may be differences, in addition it could also be possible that the other compositions of two kinds have to the antioxidant activity of polyphenol cooperate with or Antagonism leads to the difference in antioxidant activity.The difference of sweet potato stem leaf polyphenol antioxidant activity may be with total phenol content, phenol Class is constituted and the factors such as the composition of other nutriments are related.

7 40 kinds of sweet potato leaves and stems total phenol contents of table and antioxidant activity

Note: the different letters of same row indicate that there are significant difference (p < 0.05) between different cultivars.

In conclusion sweet potato leaves and stems are excellent compared with storage tolerance rich in nutrients such as protein, cellulose, carbohydrate The Vegetable Resources of matter.Sweet potato leaves and stems content of mineral substances is abundant, is rich in the elements such as potassium, calcium, magnesium, iron, and the sweet potato of most of kind Cauline leaf K/Na ratio with higher, has effects that the prevention of potential quality to hypertension and atherosclerosis；

Sweet potato stem leaf polyphenol total phenol content is high, and average content is 6.97 ± 2.89g CAE/100g DW；Different cultivars sweet potato The antioxidant activity significant difference (p < 0.05) of cauline leaf, the stronger kind of antioxidant activity have Chongqing purple 7 etc.；

In short, sweet potato leaves and stems nutrition is balanced and is rich in bioactivity polyphenol, a kind of novel leafy vegetable resource can be used as And the plant origin of active polyphenol is subject to development and application.

Test example 3

This test example verifies different harvest times for the nutrition of sweet potato leaves and stems green juice powder and functional components and anti-oxidant Activity.

Take three harvest times (harvest time 1 (H1): on August 10th, 2017；Harvest time 2 (H2): August 30 in 2017 Day；Harvest time 3 (H3): on September 20th, 2017；Implantation time is five months bottoms) sweet potato vine top 10-15cm cauline leaf Part (takes measurement of the sample segment for moisture content) after cleaning, draining, -39 DEG C of pre-freeze 12h, -56 DEG C, 45Pa carry out it is true 72h at vacuum freecing-dry.Sweet potato leaves and stems after freeze-drying are crushed, cross 40 meshes, gained cauline leaf powder is placed in aluminium foil valve bag in 4 DEG C refrigerator storage is spare (moisture content 6.0-8.0%), detects the color of the sweet potato leaves and stems of different harvest times by the following method With nutrition and functional components and antioxidant activity.

1 detecting step

(1) protein, fat, ash content, calcium, potassium, phosphorus, magnesium, sodium, iron, manganese, zinc and Cupper determination method are the same as test example 1；

(2) measuring method of moisture, energy, carbohydrate and lead is the same as test example 2；

(3) measurement of selenium: referring to the first method of GB 5009.93-2017；

(4) measurement of lead: referring to the first method of GB 5009.12-2017；

(5) measurement of mercury: referring to first the first method of GB 5009.17-2014；

(6) measurement of arsenic: referring to first the second method of GB 5009.11-2014；

(7) vitamin B₁: referring to the second method of GB 5009.84-2016；

(8) vitamin B₂: referring to the second method of GB 5009.85-2016；

(9) vitamin B₃: referring to the first method of GB 5009.89-2016；

(10) vitamin E: referring to the first method of GB 5009.82-2016；

(11) measurement of dietary fiber, soluble dietary fiber and insoluble dietary fiber: referring to GB 5009.88- 2014；

(12) it the measurement of color: is measured using color evaluating, wherein L value represents brightness, and L=0 indicates black, L= 100 indicate white；A, b value constitutes a rectangular coordinate system, determines tone, and+a value is bigger, and close to pure red ,-a value is bigger, close It is pure green；+ b is bigger, and yellow increases, and-b value is bigger, and blue increases.It takes sample powder to be placed in instrument connection, is compacted, measures the coloration of powder Value.

(13) preparation of polyphenol crude extract and the measurement of total phenol content: method is the same as test example 1；

(14) ABTS free radical scavenging ability method and ferric ion reduction activation measuring method (FRAP method): method is the same as examination Test example 1；

(15) sweet potato stem leaf polyphenol crude extract the measurement of DPPH oxidation resistance: is configured to mass concentration point with distilled water Not Wei 5.0,7.0,10.0,15.0,20.0 μ g/mL sample solutions, take 2.0mL sample solution be added 2.0mL 6 × 10^-5mol/L DPPH ethanol solution is protected from light after fierceness concussion and keeps 60min, measures light absorption value at 517nm immediately.Using ascorbic acid as Standard items, the DPPH scavenging capacity of sample be expressed as mg ascorbic acid (ascobic acid equivalent, ACE)/ 100g DW。

2 measurement results

(1) color of the sweet potato leaves and stems of different harvest times

The color of the sweet potato leaves and stems of the different harvest times of table 8

Note: the different letters of same row indicate that there are significant difference (p < 0.05) between different harvest times；

*: moisture content is in terms of fresh weight, (g/100FW)

As known from Table 8, the brightness (L value) of the sweet potato leaves and stems of different goods receiving times, has significant difference, wherein when harvesting Between be H3 when, color is most bright；From a value can be seen that wherein harvest time be H3 when, color is most green.

(2) Principle components analysis

The basic nutrition ingredient of the sweet potato leaves and stems of the different harvest times of table 9

As known from Table 9, the content of the basic nutrition ingredient of the sweet potato leaves and stems of different harvest times has significant difference (p < 0.05).Harvest time is that moisture, ash content, fat, the protein content of H3 is minimum, and dietary fiber includes soluble dietary fibre Peacekeeping insoluble diedairy fiber content does not have significant difference (p < 0.05).

(3) minerals and vitamins content analysis

The minerals and vitamins content of the sweet potato leaves and stems of the different harvest times of table 10

Note: with a line, different letters indicate that there are significant difference (p < 0.05) between different harvest times；

As known from Table 10, the minerals and vitamins content of the sweet potato leaves and stems powder of different harvest times has significant difference (p < 0.05).All kinds of minerals and vitamins contents are higher in the sweet potato leaves and stems of H1 harvest, each in the sweet potato leaves and stems of H2 harvest Quasi-mineral and vitamin content take second place, and calcium, potassium, zinc, magnesium, selenium, the vitamin B that the sweet potato leaves and stems of H3 harvest contain₃It is higher. Lead detected by the sweet potato leaves and stems of three harvest times, mercury, arsenogen cellulose content are extremely low, illustrate sweet potato leaves and stems safety non-pollution.

(4) total phenol content and antioxidant activity

The total phenol content and antioxidant activity of the sweet potato leaves and stems of the different harvest times of table 11

Note: CHAE represents chlorogenic acid equivalent；ACE represents ascorbic acid；TE represents trolox equivalent；

With a line, different letters indicate that there are significant difference (p < 0.05) between different harvest times.

As known from Table 11, the total phenol content of the sweet potato leaves and stems of different harvest times and antioxidant activity have conspicuousness poor It is different.The total phenol content highest of the sweet potato leaves and stems of H3 harvest, the sweet potato leaves and stems of followed by H2 harvest, least total phenol content is that H1 is received The sweet potato leaves and stems obtained.It is analyzed using DPPH antioxidation method, the antioxidant activity of the sweet potato leaves and stems of three harvest times is not significant Sex differernce；The anti-oxidant of the sweet potato leaves and stems of H3 harvest is obtained using ferric ion reduction activation measuring method (FRAP method) analysis Active highest is significantly higher than the antioxidant activity of the sweet potato leaves and stems of other two harvest times；Using ABTS radical scavenging activity Force method analysis, it is the sweet potato leaves and stems of H3 harvest that antioxidant activity is highest, is secondly the sweet potato leaves and stems of H2, H1 harvest respectively.

Test example 4

Whether this test example verifies the cutting of sweet potato leaves and stems for the nutrition of sweet potato leaves and stems green juice powder and functional components and Antioxidant activity influences (corresponding embodiment 3 and embodiment 11).

Sweet potato leaves and stems are divided into the sweet potato leaves and stems group for being cut into 1-3cm and the whole sweet potato leaves and stems group without cutting, then Be respectively put into blanching 2min in the stainless steel pan for fill boiling water, finally in -39 DEG C of pre-freeze 12h, -56 DEG C, 45Pa carry out it is true 72h at vacuum freecing-dry.Sweet potato leaves and stems after freeze-drying are crushed, cross 40 meshes, gained cauline leaf powder is placed in aluminium foil valve bag in 4 DEG C refrigerator storage is spare (moisture content 6.0-8.0%), detect by the following method the sweet potato leaves and stems of different disposal nutrition and Functional components and antioxidant activity.

1 detecting step

(1) moisture, protein, fat, carbohydrate, dietary fiber (soluble dietary, insoluble dietary fiber) Energy, ash content, vitamin B1, vitamin B2, vitamin B3, vitamin E, calcium, potassium, phosphorus, magnesium, sodium, iron, manganese, zinc, copper, selenium, Lead, mercury, arsenic measuring method with test example 3；

(2) ascorbic measurement: referring to the second method of GB 5009.86-2016；

(3) measurement of folic acid: referring to GB 5009.211-2014；

(4) beta carotene: referring to GB 5009.83-2016；

The measurement of (5) 16 kinds of amino acid composition: referring to GB 5009.124-2016；

(6) measurement of color, the preparation of polyphenol crude extract, the measurement of total phenol content, the measurement of ferric ion reduction activation Method (FRAP method) is the same as test example 3.

2 measurement results

(1) influence of the different disposal to sweet potato leaves and stems main component

As known from Table 12, different processing modes has significant impact (p < to the main component in sweet potato leaves and stems 0.05).Energy, carbohydrate and the protein content of the sweet potato leaves and stems of whole blanching freeze-drying are high；Cutting blanching is lyophilized sweet The protein of potato cauline leaf, dietary fiber (soluble dietary fiber, insoluble diedairy fiber) content are high.

The main component (g/100g DW) of the sweet potato leaves and stems of 12 different disposal of table

Note: with a line, different letters indicate that there are significant difference (p < 0.05) between different disposal；

* the unit of energy is kJ/100g.

(2) influence of the different disposal to sweet potato leaves and stems content of mineral substances

As known from Table 13, different processing modes has significant impact (p < to the content of mineral substances in sweet potato leaves and stems 0.05).The content of the phosphorus of sweet potato leaves and stems of whole blanching freeze-drying, copper and selenium is high；The sodium of the sweet potato leaves and stems of cutting blanching freeze-drying, Phosphorus, the content of calcium are high.

The content of mineral substances (mg/100g DW) of the sweet potato leaves and stems of 13 different disposal of table

* the content of selenium is indicated with μ g/100g.

(3) influence of the different disposal to sweet potato leaves and stems contents of heavy metal elements

As known from Table 14, contents of heavy metal elements is all satisfied the country of solid beverage in the sweet potato leaves and stems of Different treatments Standard (limitation of arsenic is 0.5mg/100g)

The contents of heavy metal elements (mg/100g DW) of the sweet potato leaves and stems of 14 different disposal of table

(4) influence of the different disposal to sweet potato leaves and stems vitamin content

As known from Table 15, Different treatments have significant impact (p < 0.05) to the vitamin content of sweet potato leaves and stems. The vitamin B2 of sweet potato leaves and stems of whole whole blanching freeze-drying, vitamin B3, the content of folic acid and vitamin E are high；Cutting blanching β-carrotene, vitamin B3, folic acid and the ascorbic content of the sweet potato leaves and stems of freeze-drying are high.

The vitamin content (mg/100g DW) of the sweet potato leaves and stems of 15 different disposal of table

* the content of beta carotene and folic acid is indicated with μ g/100g.

(5) influence of the different disposal to sweet potato leaves and stems amino acid content

As known from Table 16, Different treatments have significant impact (p < 0.05) to the amino acid content of sweet potato leaves and stems. Whole blanching freeze-drying sweet potato leaves and stems Mid-Heaven Gate aspartic acid, threonine, serine, glutamic acid, alanine, valine, tyrosine, The content of phenylalanine and lysine is high；Cutting blanching freeze-drying sweet potato leaves and stems in threonine, serine, glutamic acid, proline, Glycine, alanine, valine, isoleucine, leucine, phenylalanine, lysine, histidine and arginic content are high.

The amino acid content (g/100g DW) of the sweet potato leaves and stems of 16 different disposal of table

(6) influence of the different disposal to sweet potato leaves and stems total phenol content and antioxidant activity

The total phenol content of gained sweet potato leaves and stems powder is shown in Table 17 after blanching is lyophilized, and as can be seen from the table, non-blanching is straight The total phenol content highest of freeze-drying sweet potato leaves and stems is connect, is 6.42 ± 0.25g CAE/100g DW, after blanching color protection, sweet potato The total phenol content conspicuousness of cauline leaf has dropped (p < 0.05), and the total phenol content of whole blanching freeze-drying sweet potato leaves and stems has lost 23.66%, and the total phenol content of the sweet potato leaves and stems of cutting blanching freeze-drying has lost 54.87%.The reason is that during blanching, Sweet potato leaves and stems cell is destroyed, and many active material outflows are dissolved in the water, thus cause damages, and phase is lyophilized in cutting blanching For than whole blanching freeze-drying, the broken area of sweet potato leaves and stems is less, protects the loss of active material to a certain extent.

The antioxidant activity of the sweet potato leaves and stems of different disposal is shown in Table 17, as can be seen from the table, what non-blanching was directly lyophilized The antioxidant activity highest of sweet potato leaves and stems is 14.76 ± 0.29g TE/100g DW, cutting blanching freeze-drying and whole blanching freeze-drying Antioxidant activity compared with control group all there is significant difference (p < 0.05), the antioxidant activity decline of whole blanching freeze-drying 20.26%, and the antioxidant activity of cutting blanching freeze-drying has dropped 56.41%, is shown by data it is found that its antioxidant activity It is with uniformity with total phenol content.

Influence of 17 different disposal of table to sweet potato leaves and stems total phenol content and antioxidant activity

Note: letter indicates the otherness (p < 0.05) between different disposal

(7) influence of the different disposal to sweet potato leaves and stems color

Influence of the different blanching modes of table 18 to sweet potato leaves and stems color

Note: letter represents the otherness (p < 0.05) between different blanching modes

After different disposal, the L* values of sweet potato leaves and stems, a* value, the situation of change of b* value and △ E* value are as shown in table 17.From As can be seen that the L* value that non-blanching is directly lyophilized is 43.25 ± 0.45 in table, the L* of cutting blanching freeze-drying and whole blanching freeze-drying Value is respectively 41.14 ± 0.34,40.83 ± 0.63, and non-blanching is directly lyophilized and compares with the sweet potato leaves and stems being lyophilized after blanching, There are significant difference (p < 0.05) for L* value, and the L* value between cutting blanching freeze-drying and whole blanching freeze-drying does not have notable difference (p < 0.05) illustrates that the sweet potato leaves and stems brightness being lyophilized after blanching is partially dark.Non- blanching be directly lyophilized and blanching after the Sweet Potato that is lyophilized There were significant differences (p < 0.05) for the a* value of leaf, and the a* value between cutting blanching freeze-drying and whole blanching freeze-drying does not have notable difference (p < 0.05), the a* value of the sweet potato leaves and stems after blanching exist significant difference (p < 0.05) compared with the control group, but all in green.No B* value with processing illustrates that sweet potato leaves and stems that non-blanching is directly lyophilized are lyophilized compared with cutting blanching there are significant difference (p < 0.05) Sweet potato leaves and stems powder, the obvious inclined yellow of color.In conclusion the sweet potato leaves and stems by different disposal, color there are notable difference, Two groups of colors that discovery is lyophilized by cutting blanching freeze-drying and whole blanching after reconstituting are obviously greener compared with control group, and can tie up It holds non-discolouring for a long time (> 1 hour).

Test example 5

This test example is verified different enzyme deactivation modes to the nutrition of the sweet potato leaves and stems green juice powder of preparation and functional components and is resisted Oxidation activity influences (corresponding embodiment 1,3,4).

Sweet potato leaves and stems are cleaned up with tap water, and are dried sweet potato leaves and stems with blotting paper.Accurately weigh 1200g sweet potato Cauline leaf is equally divided into 4 parts (every part of 300g), wherein 1 part without any processing, other 3 parts using following 3 kinds different enzyme deactivation modes Processing, and carry out 3 parallel tests.

Blanching enzyme deactivation: 100g sweet potato leaves and stems are put into the stainless steel pan for fill 500mL boiling water and boil 2min；Steam Enzyme deactivation: 100 g sweet potato leaves and stems are put into pallet, and the pallet for filling sweet potato leaves and stems is put into the steamer middle cover lid for filling boiling water 2 min are steamed at normal atmospheric pressure；Microwave deactivating enzyme: 100g sweet potato leaves and stems are put into glass saucer, then will fill sweet potato leaves and stems Glass saucer be put into business -1000W micro-wave oven in high fire processing 2min；By processing and sweet potato leaves and stems without any processing in- 39 DEG C of pre-freeze 12h, -56 DEG C, 45Pa carry out 72h at vacuum freeze drying.Sweet potato leaves and stems after freeze-drying are crushed, cross 40 meshes, Gained cauline leaf powder is placed in aluminium foil valve bag spare (moisture content 6.0-8.0%) in 4 DEG C of refrigerator storages.

1 determination step

(1) moisture, crude fat and crude protein content are measured according to the method for AOAC (2000).Ash content is sweet by weighing Potato cauline leaf sample heats the weight before and after 12h at 550 DEG C and determines.Crude fat content is surveyed according to the method for AOAC960.39 It is fixed.Crude protein content is measured by Kjeldahl's method, and the conversion coefficient of nitrogen to albumen is 6.25 (AOAC976.05).

(2) crude fiber content is measured according to the method for ISO5498:1981.Firstly, by a certain amount of sweet potato leaves and stems powder Sample boils 30min in 0.255 M sulfuric acid, by insoluble sludge filtering, the cleaning of generation, and in 0.313M sodium hydroxide It boils, after then cleaning sample filtering, in 130 ± 2 DEG C of dry 2h.In 350 ± 25 DEG C of measurement weight loss.Crude fiber content It is represented as g/100g DW.

(3) measurement of total phenol content

The measurement of sample total phenol content forint phenol reagent process referring to described in (2002) such as Yoshimoto.Specific steps are such as Under: weigh under ethyl alcohol → Ultrasonic Conditions of the 1.0g sample by solid-liquid ratio 1:20 (w/v) addition 20mL 70% (50 DEG C, 30min → centrifugation (5000g, 4 DEG C) 10min → collection supernatant 59KHz) is extracted, residue repeats to extract two according to the method described above Secondary, combined extract, 45 DEG C of rotary evaporations remove ethyl alcohol, are settled to 30mL with distilled water, and sweet potato stem leaf polyphenol crude extract is made.

It takes the above-mentioned crude extract of 0.5mL that the forint phenol reagent of 1.0mL10% (v/v) is added, is reacted in 30 DEG C of water-baths Then 30min is added the sodium carbonate liquor of 2.0mL10% (w/v), reacts 30min in 30 DEG C of water-baths after mixing well, stand Absorption photometric value is measured at 736nm.Using the chlorogenic acid standard solution of 0.02,0.04,0.06,0.08,0.10mg/mL Standard curve is established, equation of linear regression y=8.7671x+0.0068, R are obtained²=0.9994.Total phenol content is represented as the green original of g Acid equivalent (chlorogenic acid equivalent, CAE)/100g sample dry weight.

(4) oxygen radical absorbability

Specific step is as follows: all solution use 75mmol/L in this method, and pH=7.4 phosphate buffer solution is matched It sets and dilutes.Be added in 96 microwell plates 20 μ L samples to be tested (each sample measures 3 different 5,10,20 μ g/mL of concentration), After 37 DEG C of heat preservation 10min, 140 μ are added in the Fluress of 20 μ L phosphate buffer solutions, 20 μ L 63nmol/L immediately The AAPH solution of L18.28mmol/L is placed in multi-function microplate reader (Chameleon V, Hidex, Finland), in excitation wave Fluorescent value is measured under long 485nm and launch wavelength 535nm, time interval is set as 2.0min, and measurement number is 60 times, measuring temperature It is 37 DEG C.Fluorescent value of each reaction solution when no AAPH is acted on is measured simultaneously (to be replaced with the phosphate buffer solution of equivalent AAPH solution), relative intensity of fluorescence value is calculated by formula 1.Fluorescence decay AUC is calculated by formula 2 using approximate integration.Use phosphorus Hydrochlorate buffer solution replaces sample solution to indicate each sample as blank control, and with sample solution and the netAUC of blank control Oxygen radical absorbability, as shown in formula 3.Using watermiscible vitamin E as standard items, the oxygen radical of sample solution is inhaled Receipts ability is expressed as μ g watermiscible vitamin E equivalent (trolox equivalent, TE)/mL sample solution.

F_i=f_i(+AAPH)/f_i(-AAPH)(formula 1)

AUC=2 × (F₀+F₁+ ﹒ ﹒ ﹒+F_n)-F₁-F_n(formula 2)

Net AUC=AUC_sample–AUC_blank(formula 3)

Wherein f_i(+AAPH)For absolute fluorescence intensity value of the reaction solution in i-th of minute point for adding AAPH； f_i(-AAPH)For absolute fluorescence intensity value of the reaction solution in i-th of minute point for not adding AAPH；Fi is that reaction solution exists The relative intensity of fluorescence value of i-th of minute point；AUC is area under fluorescence decay curve；AUC_sampleFor the glimmering of sample solution Optical attenuation area under the curve；AUC_blankFor area under blank control fluorescence decay curve；NetAUC is sample solution and blank pair According to difference in areas under fluorescence decay curve.

(5) quantitative analysis of polyphenols each component

Sweet potato stem leaf polyphenol sample after dissolving different disposal with 80% methanol, the sample for being configured to 200 μ g/mL are molten Liquid carries out chromatography after crossing 0.45 μm of film.Chromatographic condition is as follows: ZORBAX Eclips Plus C18 chromatographic column (4.6 × 150mm, 5 μm), Detection wavelength 326nm, flow velocity 1BV/h, sample volume 20 μ L, 30 DEG C of column temperature, mobile phase A: 0.5% (w/v) phosphorus Acid buffering solution, B: acetonitrile.Gradient elution program: 0-15min:20-65%B, 15-15.1:65-80%B, 15.1-20min: 80%B.The retention time of each absorption peak and peak area in map is absorbed according to sample to carry out sample composition and each component content Analysis.

2 measurement results

(1) influence that enzyme deactivation mode forms sweet potato leaves and stems substantially

The influence that different enzyme deactivation modes form sweet potato leaves and stems substantially is as shown in table 19.With the Sweet Potato without any processing The protein content (24.04 ± 0.08g/100g DW) of leaf is compared, and blanching enzyme deactivation (25.56 ± 0.05g/100g DW), steam go out Enzyme (28.66 ± 0.14g/100g DW) and microwave deactivating enzyme (28.11 ± 0.13g/100g DW) cause the significant increasing of protein content Add (p < 0.05).Analyzing reason may are as follows: during blanching and steam enzyme deactivation, other compositions in sweet potato leaves and stems (as fat, Dietary fiber etc.) it is partially lost or destroys, lead to the relative increase of protein content.

Crude fat content is 4.39 ± 0.12g/100g DW, blanching enzyme deactivation (3.19 in sweet potato leaves and stems without any processing ± 0.14g/100g DW), steam enzyme deactivation (3.32 ± 0.12g/100g DW) and microwave deactivating enzyme (2.90 ± 0.06g/100g DW) Cause the significant decrease (p < 0.05) of crude fat content.During blanching enzyme deactivation, steam enzyme deactivation and microwave deactivating enzyme, sweet potato leaves and stems Middle effumability and water-soluble fatty acid can be partially lost or destroy, and cause the decline of fat content.

Blanching enzyme deactivation (10.47 ± 0.11g/100g DW), steam enzyme deactivation (10.41 ± 0.25g/100g DW) and microwave go out Enzyme (10.05 ± 0.08g/100g DW) significantly reduces the crude fiber content (p < 0.05) in sweet potato leaves and stems.The above results table Bright, blanching process causes a large amount of losses of water-soluble dietary fiber.During steam enzyme deactivation and microwave deactivating enzyme, although sweet Potato cauline leaf does not leak in water cruelly, but a large amount of cell liquid outflows, also results in a large amount of losses of water-soluble dietary fiber.

Blanching enzyme deactivation (7.44 ± 0.01g/100g DW), steam enzyme deactivation (8.16 ± 0.01g/100g DW) and microwave deactivating enzyme (8.17 ± 0.12 g/100g DW) processing and the ash in the sweet potato leaves and stems without any processing (7.84 ± 0.62g/100g DW) Point content is compared, and significant difference is not present.

The influence (g/100g dry weight) that the different enzyme deactivation modes of table 19 form sweet potato leaves and stems substantially

Note: same letter indicates that significant difference (p < 0.05) is not present between different enzyme deactivation modes.

(2) influence of the enzyme deactivation mode to sweet potato leaves and stems total phenol

Influence of the different enzyme deactivation modes to sweet potato leaves and stems total phenol content is as shown in Figure 2.With the Sweet Potato without any processing Leaf (12.30 ± 0.26%, DW) is compared, blanching enzyme deactivation (8.55 ± 0.16%, DW) and microwave deactivating enzyme (9.14 ± 0.12%, DW) The total phenol content of sweet potato leaves and stems is significantly reduced, and steam enzyme deactivation (13.46 ± 0.18%, DW) significantly improves sweet potato leaves and stems Total phenol content (p < 0.05).Steam enzyme deactivation makes sweet potato leaves and stems total phenol content improve 9.44%, and blanching enzyme deactivation and microwave deactivating enzyme Total phenol content is set to reduce 30.51% and 25.70% respectively.In this research, after blanching enzyme deactivation and microwave deactivating enzyme in sweet potato leaves and stems The decline of total phenol content may be because enzyme deactivation process results in the decomposition of phenolic substances.For Sweet Potato during steam enzyme deactivation The reason of total phenol content increases in leaf, there is no final conclusion, however, it is the possible reason is tannin is degraded into sweet potato leaves and stems Small molecule phenols substances.

(3) antioxidant activity

Influence of the different enzyme deactivation modes to sweet potato leaves and stems antioxidant activity is as shown in Figure 3.Sweet Potato without any processing The antioxidant activity of leaf is 1.28 ± 0.07 μ g TE/mg, DW.Compared with the sample without any processing, blanching enzyme deactivation (0.46 ± 0.07 μ g trolox equivalent/mg, DW) and microwave deactivating enzyme (0.87 ± 0.05 μ g trolox equivalent/ Mg, DW) significantly reduce the antioxidant activity of sweet potato leaves and stems, and steam enzyme deactivation (2.32 ± 0.03 μ g trolox Equivalent/mg, DW) significantly improve the antioxidant activity (p < 0.05) of sweet potato leaves and stems.Blanching enzyme deactivation and microwave deactivating enzyme point So that the antioxidant activity of sweet potato leaves and stems is had dropped 63.82% and 32.35%, matches with the downward trend of total phenol content.It is micro- The lower antioxidant activity of sample can be attributed to biggish fuel factor after wave enzyme deactivation, rather than microwave itself.In contrast, it steams Vapour enzyme deactivation makes the antioxidant activity of sweet potato leaves and stems improve 81.40%, different with the variation tendency of total phenol content in sweet potato leaves and stems It causes.This can be attributed to the generation of other redox Secondary metabolites and its catabolite, but very likely with its His the significantly more efficient release of antioxidant content is related, these antioxidant contents are from intracellular protein, plant cell wall construction Change the change with cellular matrix.

(4) quantitative analysis of polyphenols each component

The composition of polyphenols in 20 sweet potato leaves and stems of table

Influence (mg/g, DW) of the different enzyme deactivation modes of table 21 to sweet potato stem leaf polyphenol content of monomer

Obvious forint phenol colorimetric method for determining total phenol content can not completely determine the polyphenols in sweet potato leaves and stems Property and it is quantitative.Therefore, we determine the polyphenols after different enzyme deactivation modes are handled in sweet potato leaves and stems using HPLC method, tie Fruit is as shown in Fig. 4 and table 20.By compared with the retention times of standard items and ultraviolet spectra that are measured under the same terms, 8 kinds Polyphenols (5-CQA, 3-CQA, 4-CQA, CA, 4,5-CQA, 3,5-CQA, 3,4-CQA and 3,4,5-CQA) is identified out Come, the content of this 8 kinds of polyphenols is calculated by regression equation.

It is mapped according to peak area (y) and concentration (x, mg/g, DW), the regression equation of 8 kinds of polyphenols in sweet potato leaves and stems And related coefficient (R2) is as follows: 5-CQA, y=11.372x-0.428 (R2=0.996)；3-CQA, y=9.909x+ 0.286 (R2=0.999)；4-CQA, y=25.894x-17.128 (R2=0.998)；Caffeic acid, y=28.183x-1.211 (R2=0.999)；4,5-CQA, y=9.208x-7.244 (R2=0.998)；3,5-CQA, y=18.056x-18.405 (R2 =0.998)；3,4-CQA, y=15.353x-12.021 (R2=0.998)；3,4,5-CQA, y=6.218x-5.158 (R2= 0.995).The content of the polyphenols monomer in sweet potato leaves and stems handled through different enzyme deactivation modes is as shown in table 21.Pass through ratio Compared with the content of 8 kinds of polyphenols in the sweet potato leaves and stems without any processing, it has been found that: 4,5-CQA (27.23mg/g DW) > 3,5-CQA(25.02mg/g DW)>3,4-CQA(14.18mg/g DW)>4-CQA (13.55mg/g DW)>3,4,5-CQA (10.68mg/g DW) > caffeic acid (4.62mg/g DW) > 3-CQA (3.06mg/g DW) > 5-CQA (2.58mg/g DW).

For 5-CQA, blanching enzyme deactivation and steam enzyme deactivation significantly reduce its content, and microwave deactivating enzyme does not cause significantly to become Change.For 3-CQA, blanching enzyme deactivation, steam enzyme deactivation and microwave deactivating enzyme significantly reduce its content.4-CQA is contained in sweet potato leaves and stems The most abundant monosubstituted caffeoylquinic acids are measured, in these adopted enzyme inactivating methods, only blanching enzyme deactivation causes it and contains The significant decrease of amount.For caffeic acid, three kinds of enzyme deactivation modes cause being remarkably decreased for its content.4,5-CQA is sweet potato leaves and stems The middle highest disubstituted caffeoylquinic acids of content, in these enzyme deactivation modes, only blanching enzyme deactivation causes the aobvious of its content Write decline.For 3,5-CQA, in all studied enzyme deactivation modes, only blanching enzyme deactivation significantly reduces its content.For 3,4-CQA, steam enzyme deactivation significantly improves its content, and blanching enzyme deactivation significantly reduces its content.For 3,4,5-CQA, steam Vapour enzyme deactivation causes significantly improving for its content, and other enzyme deactivation modes do not cause the significant changes of its content.We are difficult to sentence Break which kind of polyphenols monomer the antioxidant activities of sweet potato leaves and stems is contributed it is maximum.Palermo has found that different enzyme deactivation modes are drawn Significantly improving for arithoke total antioxidant activity has been played, and this increase is attributed to 5-CQA and 1, the increase of 5-CQA.However, I Result it is entirely different therewith.In order to more clearly in description sweet potato leaves and stems polyphenols monomer and antioxidant activity it Between relationship, we analyze the correlation (Fig. 5) in sweet potato leaves and stems between polyphenols content of monomer and antioxidant activity. It is (0.8267) 4,5-CQA that related coefficient is maximum between sweet potato leaves and stems antioxidant activity, followed by 3,4-CQA (0.8148)、3,5-CQA (0.7474)、3,4,5-CQA(0.5830)、4-CQA(0.4554)、5-CQA(0.0270)、3-CQA (0.0158) and caffeic acid (0.0002).Therefore, the antioxidant activity of sweet potato leaves and stems may be mainly due to 4,5-CQA, 3,4- The increase of CQA, 3,5-CQA and 3,4,5-CQA content.The antioxidant activity of polyphenols is primarily due to redox spy Property, it is free that this characteristic makes them be used as reducing agent, hydrogen donor, singlet oxygen quencher, heavy metal chelant and hydroxyl Base quencher.It is disubstituted with trisubstituted caffeoylquinic acids molecular structure in there are more hydroxyls, make they with it is monosubstituted Caffeoylquinic acids compare, have bigger activity.

It is interesting that the total phenol content gone out by HPLC Analysis result calculation contains lower than the total phenol that forint phenol colorimetric method measures Amount, this may be because we are when carrying out HPLC analysis, polyphenols standard items limited amount.

Test example 6

This test example verifies nutrition and physicochemical property shadow of the different drying process for prepared sweet potato leaves and stems green juice powder It rings (corresponding embodiment 1,5,6).

Sweet potato leaves and stems are cleaned up with tap water, and are dried sweet potato leaves and stems with blotting paper.Accurately weigh 1500g sweet potato Cauline leaf is equally divided into 3 parts (every part of 500g).

Micro-wave vacuum: optimum drying parameter is microwave power 350W, vacuum degree -0.95Mpa.By 500g sweet potato leaves and stems It is laid in micro-wave vacuum case, setting temperature range is 400~50 DEG C, 2 hours dry.Sweet Potato after crushing drying Leaf sieves with 100 mesh sieve, be stored in 4 DEG C be protected from light under the conditions of it is spare.

Heated-air drying: optimum drying parameter is 60 DEG C, 12 hours dry.Sweet potato leaves and stems after crushing drying cross 100 mesh Sieve, be stored in 4 DEG C be protected from light under the conditions of it is spare.

Vacuum freeze drying: optimum drying parameter is by sweet potato leaves and stems in -39 DEG C of pre-freeze 12h, -56 DEG C, 45Pa carry out it is true 72h at vacuum freecing-dry.Crush it is dry after sweet potato leaves and stems, sieve with 100 mesh sieve, be stored in 4 DEG C be protected from light under the conditions of it is spare.

1 determination step

(1) measurement for the injectivity index that absorbs water

Referring to introduced in United States Patent (USP) method measurement, that is, take the centrifuge tube of appropriate volume, after weighing be added 2g sample and 30mL distilled water, mixes well.By above-mentioned mixed liquor under conditions of 30 DEG C water-bath 30min, after every 15min mixing is primary 3000r/min is centrifuged 15min, discards supernatant liquid, weighs after being inverted 2min.

(2) measurement of holding oiliness

It takes 0.5g sweet potato leaves and stems powder to be placed in centrifuge tube, 10mL maize germ oil is added, stands 18h after mixing, It is centrifuged 30min under the conditions of 2000r/min, weighs after discarding supernatant liquid.

Holding oiliness (g/g)=(sweet potato leaves and stems powder is by weight-sweet potato leaves and stems powder initial weight after oil saturation)/Sweet Potato The initial weight of leaf powder

(3) measurement of Expansion Potential and solubility

Take 0.35g sweet potato leaves and stems powder that 12.5mL distilled water, water-bath 30min under the conditions of 85 DEG C, later 7500r/min is added It is centrifuged 15min.Supernatant is collected to dry 2 hours and weigh at 105 DEG C.The Expansion Potential and solubility test formula of sweet potato leaves and stems It is as follows:

Solubility (%)=(weight of supernatant/sweet potato leaves and stems powder weight) * 100

Expansion Potential (g/g)=precipitating weight/(the weight * (100- solubility) of sweet potato leaves and stems powder)

(4) (soluble dietary is fine for moisture, ash content, crude protein, crude fibre, carbohydrate, fat, energy, dietary fiber Dimension, insoluble dietary fiber), vitamin C, vitamin E, beta carotene, vitamin B1, vitamin B2, total phenol and antioxygen Change activity with test example 4.

2 measurement results

(1) influence of the different drying modes to sweet potato leaves and stems powder physicochemical property

Influence of the different drying modes of table 22 to sweet potato leaves and stems powder physicochemical property

g/g

Note: same row letter indicates the otherness (p < 0.05) between different characteristics；

HAD is heated-air drying, VFD is vacuum freeze drying, MVD is micro-wave vacuum, SPL is sweet potato leaves and stems；

* the unit for representing solubility is %

The physicochemical property of sweet potato leaves and stems powder is shown in Table 22.Micro-wave vacuum sweet potato leaves and stems injectivity index highest (5.68 ± It 0.07g/g), is sweet potato leaves and stems powder (4.29 ± 0.00g/ of vacuum freeze drying (5.43 ± 0.04g/g) and heated-air drying later g).The ability of retaining oil range of three kinds of sweet potato leaves and stems samples is 1.66 to 3.86g/g.

The solubility of micro-wave vacuum sample is most strong (7.14 ± 0.50%), and the solubility of heated-air drying sample is most weak (4.29 ± 0.58%).Microwave drying (14.92 ± 0.71g/g) and heated-air drying (11.40 ± 0.20g/g) sweet potato leaves and stems powder are in Higher Expansion Potential.

(2) basis is analyzed

The measurement result of the main component of the sweet potato leaves and stems powder of different drying modes is shown in Table 23.What three kinds of drying modes obtained The average moisture content of sweet potato leaves and stems powder is 4.87g/100g DW.Highest moisture content is the resulting sweet potato of vacuum freeze drying Cauline leaf powder, content it is minimum be the resulting sweet potato leaves and stems powder of heated-air drying.Highest protein content is that heated-air drying is resulting Sweet potato leaves and stems powder (27.70 ± 0.11g/100g DW), content it is minimum be the resulting sweet potato leaves and stems powder of micro-wave vacuum (25.40±0.63g/100g DW).Crude fiber content is highest be the resulting sweet potato leaves and stems powder of micro-wave vacuum (9.60 ± 1.12g/100g DW), content it is minimum be the resulting sweet potato leaves and stems powder of heated-air drying (8.30 ± 0.08g/100g DW), it is average Content is 8.90 ± 0.52g/100g DW.The crude fat content range of three kinds of samples is 2.12 ± 0.65~3.20 ± 0.48g/ 100g DW, the crude fat content highest (3.20 ± 0.48 g/100g DW) of the resulting sweet potato leaves and stems powder of vacuum freeze drying are micro- It is minimum (2.12 ± 0.65g/100g DW) that wave is dried in vacuo resulting sweet potato leaves and stems powder crude fat content.The ash content of three kinds of samples Content range is 9.87 ± 0.18~12.56 ± 0.11g/100g DW, carbohydrate content range is 50.32 ± 0.59~ 50.73 ± 0.67 g/100g DW, energy range are 1053.00 ± 0.74~1169.00 ± 0.42kJ/100g DW.

Dietary fiber content is as shown in table 23.The total dietary fiber of vacuum freeze drying sweet potato leaves and stems powder is highest (37.90 ± 0.29 g/100g DW) is the dry resulting sweet potato leaves and stems powder (36.10 ± 0.63g/ of microwave vacuum freeze later 100g DW) and heated-air drying sweet potato leaves and stems powder (34.70 ± 0.11g/100g DW).Three kinds of drying modes sweet potato leaves and stems The average insoluble diedairy fiber content of powder is 32.01 ± 0.21g/100g DW.Obtained by vacuum freeze drying and heated-air drying Sweet potato leaves and stems powder soluble dietary fibre content it is higher, the minimum (3.80 ± 0.24g/ of micro-wave vacuum sweet potato leaves and stems powder 100g DW)。

Influence of the different drying modes to vitamin content is as shown in table 23.The resulting sweet potato leaves and stems powder of vacuum freeze drying Vitamin C content highest (92.50 ± 1.33mg/100g DW), heated-air drying sweet potato leaves and stems powder it is minimum (25.20 ± 0.89mg/100g DW).Content of vitamin E highest (6.42 ± 1.23mg/100g of vacuum freeze drying sweet potato leaves and stems powder DW), heated-air drying sweet potato leaves and stems powder is minimum (0.34 ± 0.71 mg/100g DW).β-the Hu Luo of heated-air drying sweet potato leaves and stems powder Foretell the minimum (21.50 ± 0.35mg/ of cellulose content highest (34.80 ± 0.93mg/100g DW) micro-wave vacuum sweet potato leaves and stems powder 100g DW).The vitamin B1 content highest (0.10 ± 0.04mg/100g DW) of vacuum freeze drying sweet potato leaves and stems powder, hot wind Dry sweet potato leaves and stems powder content is minimum (0.06 ± 0.00mg/100g DW).The vitamin B2 of vacuum freeze drying sweet potato leaves and stems powder Content highest (1.31 ± 0.49mg/100g DW), minimum (0.77 ± 0.02 mg/100g of heated-air drying sweet potato leaves and stems powder content DW)。

Influence of the different drying modes of table 23 to the basis of sweet potato leaves and stems powder, dietary fiber and vitamin content

* the unit for representing ability is kJ/100g DW.

(3) total phenol content and antioxygenic activity analysis

Fig. 6 is shown in influence of the different drying modes to the total phenol content of sweet potato leaves and stems powder.Vacuum freeze drying sweet potato leaves and stems powder Total phenol content highest (6.30 ± 0.06g CAE/100g DW), is micro-wave vacuum (6.06 ± 0.02g CAE/ later 100g DW) and heated-air drying (4.72 ± 0.09g CAE/100g DW).

Fig. 6 is shown in the result influence of antioxidant activity.Vacuum freeze drying sweet potato leaves and stems powder antioxidant activity is most strong by 20.58 ± 1.01g TE/100g DW is followed by the sweet potato leaves and stems powder of micro-wave vacuum, is 18.96 ± 0.98g TE/100g DW, resists It is the sweet potato leaves and stems powder of heated-air drying that oxidation activity is the smallest, is 8.04 ± 0.30g TE/100g DW.

Test example 7

The influence for reconstituting stability of this test example verifying embodiment 1,7-9 products obtained therefrom.

No.1 Simon sweet potato cauline leaf is taken, after cleaning, draining, -39 DEG C of pre-freeze 12h, -56 DEG C, 45Pa progress vacuum freeze drying Locate 72h.By after freeze-drying sweet potato leaves and stems Universalpulverizer or micronizer crush, obtain 80 mesh, 100 mesh, 200 mesh sweet potatoes Cauline leaf powder and Ultramicro-powder analyze its particle diameter distribution by laser fineness gage.Measure the different sweet potatoes for crushing mesh number respectively again The stratification rate of cauline leaf powder, preferably sample reconstitute the best crushing mesh number of stability.

1 determination step

(1) measurement of partial size

400mL ultrapure water is added in the disperser of laser fineness gage, a small amount of sweet potato leaves and stems powder is added, concentration is 10%~20% (w/v) is uniformly mixed, and continues the measurement of partial size under room temperature after circulation dispersion 5min.

(2) measurement of stability is reconstituted

It takes 2g difference to crush the sweet potato leaves and stems powder of mesh number respectively, 100mL boiling water is added, after being stirred evenly with glass bar, by quiet It sets layering ratio observation measurement sweet potato leaves and stems powder and reconstitutes stability, stratification rate value is smaller, and it is better to illustrate that sample reconstitutes stability. Stratification rate (%)=(volume/solid beverage total volume is precipitated in upper water) * 100.

2 measurement results

(1) the different influences for crushing mesh number to sweet potato leaves and stems powder particle diameter distribution

The particle diameter distribution of sweet potato leaves and stems powder that difference crushes mesh numbers is shown in Table 24, and it is as shown in the table, compare volume mean diameter D [4, 3], 80 mesh > 100 mesh > 200 mesh > Ultramicro-powder；Comparative surface area average diameter D [3,2], 80 mesh > 100 mesh > 200 mesh > Ultramicro-powder；80 Purpose sweet potato leaves and stems powder cumulative distribution to 50%, 90% partial size corresponding to it be respectively 128.57 ± 0.86 μm, 322.94 ± 3.36 μm are approximately Ultramicro-powder cumulative distribution to 50%, 4 times of partial size corresponding to 90%；Sweet potato leaves and stems powder by ultramicro grinding There is 92.73% partial size less than 100 μm, 73.10% partial size is less than 50%；Thus it can illustrate that the partial size of Ultramicro-powder is minimum, Secondary is the sweet potato leaves and stems powder of 100 mesh and 80 mesh.

The different influences for crushing mesh number to sweet potato leaves and stems powder particle diameter distribution of table 24

(2) the different influences for crushing mesh number and reconstituting stability to sweet potato leaves and stems powder

According to Stokes (Stokes) rule, the solids diameter in suspension system is smaller, then suspension system is more stable. Difference crushes the influence that mesh number reconstitutes stability to sweet potato leaves and stems powder and sees Fig. 7, as shown, in 0~10 minute, stratification The sweet potato leaves and stems powder of maximum 100 mesh of rate, followed by 80 mesh, 200 mesh and Ultramicro-powder, then illustrate sinking speed it is most fast be 100 Purpose sweet potato leaves and stems powder, sinking speed it is most slow be Ultramicro-powder.In 10~30 minutes, maximum stratification rate is that 80 mesh are sweet Potato cauline leaf powder, followed by 100 mesh, 200 mesh and Ultramicro-powder.In 30~60 minutes, the variant sweet potato leaves and stems powder for crushing mesh number Stratification rate no longer change substantially.It follows that sweet potato leaves and stems powder sinking speed is most slow with the extension of time of repose It is Ultramicro-powder, followed by 100 mesh and 200 mesh samples, 80 mesh sweet potato leaves and stems powder sinking speed are most fast, so by ultramicro grinding Sweet potato leaves and stems powder reconstitutes that stability is good, therefore Ultramicro-powder is selected to be used to processing raw material as sweet potato leaves and stems powder.And material is through super After Crushing of Ultrafine, the dispersibility and digestibility of material can be improved.

Test example 8

This test example demonstrates the guarantor of 1 products obtained therefrom of embodiment digestion front and back soluble protein, polyphenol and antioxidant activity Stay rate.

By Mouthsimulator, stomach and intestinal digestion system research Sweet Potato Leaf powder digestion front and back soluble protein, polyphenol and anti- The variation of oxidation activity.The result shows that soluble protein and polyphenol content and antioxidant activity are equal in Sweet Potato Leaf powder after digestion It is significant be higher than digestion before.

25 sweet potato leaves and stems powder product of table digestion front and back soluble protein content, total phenol content and antioxidant activity

Test example 9

According to a kind of resulting sweet potato leaves and stems green juice powder of embodiment 1,4 different storage time (just production, 6 are taken respectively Month, 12 months and 18 months) sweet potato leaves and stems green juice powder, the sweet potato leaves and stems for detecting different storage times by the following method are green The color of juice powder and nutrition and functional components and antioxidant activity.

1 detecting step

(1) protein, fat, dietary fiber, sodium, vitamin C, potassium, calcium, iron and Direct spectrophotometry method are the same as test example 1；

(2) measurement of energy, carbohydrate: method is the same as test example 2；

(3) dietary fiber, ascorbic measurement: method is the same as test example 3；

(4) measurement of color: method is the same as test example 3；

(6) measurement of oxidation resistance: method is the same as test example 1；

2 measurement results

(1) color of the sweet potato leaves and stems green juice powder of different storage times

The color of the sweet potato leaves and stems green juice powder of the different storage times of table 26

The color change situation of the sweet potato leaves and stems green juice powder of different storage times is (can refer to attached drawing 8-11) as shown in table 26, As seen from table, the brightness value for storing 12 months sweet potato leaves and stems green juice powders does not differ significantly, and emerald green color is presented, and When storage time reaches 18 months, brightness increases than before, is but the sweet potato because chlorophyll has the reason of slight decomposition The color of cauline leaf green juice powder still presents emerald green.

The sweet potato leaves and stems green juice powder nutritional ingredient of the different storage times of table 27

The nutritional ingredient situation of change of the sweet potato leaves and stems green juice powder of different storage times is as shown in table 27, as seen from table, After 18 months storages, the protein of sweet potato leaves and stems, fat, dietary fiber, sodium, calcium, potassium content without conspicuousness Variation, energy, carbohydrate, iron, zinc and ascorbic content still retention rate are 95% or more.

The sweet potato leaves and stems green juice powder total phenol content and antioxidant activity of the different storage times of table 28

The total phenol content and antioxidant activity situation of change of the sweet potato leaves and stems green juice powder of different storage times are as shown in table 28, As seen from table, after the storage by 18 months, the retention rate of the total phenol contents of sweet potato leaves and stems and antioxidant activity 90% with On.

In conclusion although present invention sweet potato leaves and stems green juice powder obtained is not added with the products such as any preservative, still Shelf life is long.

Test example 10

This test example verifies sensory testing's experiment of green juice powder provided by embodiment 1-11.

Subjective appreciation group is formed by 10 trained Majors of Food students, from color, smell, tissue morphology and taste 4 aspects of taste score to the sweet potato leaves and stems green juice powder after reconstituting, and full marks are 100 points, remove best result and minimum point, put down It is respectively then the sensory evaluation scores of the product, sensory evaluation scores detailed rules and regulations are shown in Table 2

29 sweet potato leaves and stems green juice powder sensory evaluation criteria of table

Analyses Methods for Sensory Evaluation Results is as follows:

30 sweet potato leaves and stems green juice powder Analyses Methods for Sensory Evaluation Results of table

Sweet potato leaves and stems green juice powder Analyses Methods for Sensory Evaluation Results is as shown in table 30, and as seen from table, highest sensory evaluation scores are embodiments 1 Sweet potato leaves and stems green juice powder obtained, color is emerald green, sweet potato leaves and stems fragrant is suitable for, and dissolubility is good, delicate mouthfeel.

Although above having used general explanation, specific embodiment and test, the present invention is made to retouch in detail It states, but on the basis of the present invention, it can be made some modifications or improvements, this is apparent to those skilled in the art 's.Therefore, these modifications or improvements without departing from theon the basis of the spirit of the present invention, belong to claimed Range.

Claims

1. a kind of preparation method of sweet potato leaves and stems green juice powder, which is characterized in that including carrying out destroy the enzyme treatment to the sweet potato leaves and stems The step of；

The destroy the enzyme treatment is selected from one or more of scalding treatment, steam treatment and microwave treatment；

The scalding treatment be by the sweet potato leaves and stems in boiling water 2~7min of blanching；

The steam treatment is by the sweet potato leaves and stems with 100 DEG C and 15~180s of temperatures above steam blanching；

The microwave treatment is by the sweet potato leaves and stems with 2~3min of fire processing high in 800~1000W micro-wave oven.

2. preparation method according to claim 1, which is characterized in that the destroy the enzyme treatment is the steam treatment.

3. preparation method according to claim 1 or 2, which is characterized in that the kind of the sweet potato is Simon No.1.

4. preparation method according to claim 1-3, which is characterized in that the sweet potato leaves and stems are Later growth Sweet potato leaves and stems are the 3-4 months sweet potato leaves and stems harvested of after planting growth.

5. preparation method according to claim 1-4, which is characterized in that after Yu Suoshu destroy the enzyme treatment, further include Dry step；The drying is selected from one or more of heated-air drying, micro-wave vacuum and vacuum freeze drying；

The temperature of the heated-air drying is 50~60 DEG C, and the time is 12~15 hours；

The microwave power of the micro-wave vacuum is 300~350W, and vacuum degree is -0.95~-1.0MPa, and temperature is 40~50 DEG C, the time is 2~3 hours；

The step of described vacuum freeze drying include: first -39 DEG C~-45 DEG C pre-freeze 10~12 hours, then to carry out vacuum dry Dry, the temperature of the vacuum freeze drying is -50~-56 DEG C, and vacuum degree is 40~45Pa, and the time is 72~80 hours；

It preferably, is the vacuum freeze drying.

6. preparation method according to claim 1-5, which is characterized in that further include crushing after the drying The step of: the sweet potato leaves and stems are crushed to 80-200 mesh or Ultramicro-powder；

Preferably, it is crushed to Ultramicro-powder and crosses 0.15mm sieve.

7. preparation method according to claim 1-6, which is characterized in that using by cutting or whole Sweet potato leaves and stems.

8. preparation method according to claim 1-7, which is characterized in that including successively being washed to the sweet potato leaves and stems Only, dry, the destroy the enzyme treatment, the drying, the crushing and packaging the step of.

9. preparation method according to claim 8, which is characterized in that with one of PE, PA, AL, PET, RCPP or several The packaging bag of kind material is packed.

10. a kind of sweet potato leaves and stems green juice powder, which is characterized in that obtained by the described in any item preparation methods of claim 1-9；

Preferably, the granularity of the sweet potato leaves and stems green juice powder is lower than 104.2 microns.