CN113786367A

CN113786367A - Preparation method and application of lotus leaf extract

Info

Publication number: CN113786367A
Application number: CN202111200864.4A
Authority: CN
Inventors: 冯磊; 刘逸华; 贺青; 刘露
Original assignee: Baocui Biotechnology Co ltd
Current assignee: Baocui Biotechnology Co ltd
Priority date: 2021-10-14
Filing date: 2021-10-14
Publication date: 2021-12-14

Abstract

The invention provides a preparation method and application of a lotus leaf extract, wherein the preparation method comprises the following steps: (1) weighing a lotus leaf medicinal material, adding water for reflux extraction, extracting for 1-3 times, filtering to obtain a total flavone extracting solution, and concentrating the total flavone extracting solution to 0.5-2 times of the weight of the lotus leaf medicinal material, wherein the material-liquid ratio of the lotus leaf medicinal material to the water is 1g: 15-30 mL; (2) adding an acid solution into the concentrated solution, wherein the adding amount of the acid solution accounts for 1-6% of the mass of the concentrated solution, and heating, refluxing and hydrolyzing for 0.5-5 h; (3) filtering the hydrolysis solution while the hydrolysis solution is hot, and decoloring the filtrate to obtain a decoloring solution; (4) drying the decolorized solution to obtain folium Nelumbinis extract. The preparation process adopts an acid hydrolysis method to hydrolyze flavonoids in lotus leaves to obtain flavonoid aglycone, so that the antioxidation of the product is improved; in addition, a decoloring process is adopted, so that the color of a decolored product is lighter, and the color is not obviously changed in the standing process.

Description

Preparation method and application of lotus leaf extract

Technical Field

The invention belongs to the technical field of plant extraction, and particularly relates to a preparation method and application of a lotus leaf extract.

Background

The distribution of lotus roots in China is very wide, the cultivation area of the lotus roots is 900-1100 mu of a thousand, the lotus roots are mainly distributed in Anhui, Hubei, Hunan, Guangxi, Guangdong, Jiangxi, Fujian, Jiangsu, Zhejiang, Shandong, Hebei and other provinces, the yield of dry lotus leaves in one mu of lotus pond is about 300 kilograms according to the normal planting condition, the yield of dry lotus leaves in the market is about 15 yuan/kg, and the yield of lotus leaves in one mu of lotus pond can be increased by about 4500 yuan each year. However, the utilization rate of lotus leaf resources in China is very low and is less than 1% of the lotus leaf yield in China. Every year, a large area of lotus leaves are not harvested and are allowed to decay, so that great resource waste is caused, which is in contradiction with huge lotus leaf resources owned by China. As lotus leaves lack the research and development of related high-added-value deep-processed products, the reasonable utilization of lotus leaf resources in China is severely restricted by factors such as low market demand and the like, and the review shows that the development of the lotus leaves is carried out, the functional components in the lotus leaves are used as indexes to prepare raw materials with functional effects, scientific basis is provided for the conversion of the lotus leaves into important resources of high-added-value products, and the development and utilization of the lotus leaf resources in China are promoted.

The lotus leaves are rich in flavonoids which are scavengers of most oxygen free radicals, so the lotus leaf flavonoids are substances with great value and to be developed and can be widely applied to cosmetics, health-care foods and beverages. The flavonoid active substance in the lotus byproduct (lotus leaves) is extracted and processed by using modern high and new technology to be used as the development of cosmetics, so that the method conforms to the market demand, has very wide market sales space, greatly improves the economic value of lotus, and brings more additional value and profit space for lotus leaf production and processing. The flavone in folium Nelumbinis mainly comprises quercetin, kaempferol, hyperoside, quercetin-3-O-glucuronide, etc.

In patent CN 109467581A, quercetin-3-O-glucuronide products with purity of more than 99.22% are obtained by water extraction, resin adsorption and purification and the like; in patent CN 106749456A, weak base water extraction is adopted, and resin adsorption separation is carried out to obtain a high-purity hyperin product. The patent CN 103479731A purifies and separates the lotus leaf extract by a macroporous adsorption resin column to obtain the high-purity lotus leaf flavone. These patents all refer to the purification of total flavonoids from lotus leaves or the purification of flavonol glycosides in total flavonoids. In nature, flavonoids mostly exist in the form of flavonoid glycosides, and a very small amount exists in the form of free flavonoid aglycones. Although the naturally occurring free flavonoide aglycones are very low in content, they exhibit much higher activity than the bound glycosides. Research shows that the biological activity of the flavonoid aglycone for eliminating the oxygen free radical of the human body is obviously superior to that of the flavonoid glycoside, and the potency of the flavonoid aglycone is 7 times that of the flavonoid glycoside. Therefore, the configuration of the flavone is improved, and the antioxidation of the flavone can be improved.

In the aspect of raw materials of lotus leaf extract powder, the number of the lotus leaf extract powder is 10: 1. 20: 1. 30: 1, 2% of nuciferine, 4% of nuciferine, 98% of nuciferine, 10% of total flavonoids, 20% of total flavonoids and 30% of total flavonoids; these crude extracts were only isolated from the lotus leaf material. In the aspect of liquid raw materials, a cosmetic raw material which takes 40% of butanediol as a solvent and 1.5-3.5% of lotus leaf extract powder for dissolving and mixing is known, the main functional component is a flavonoid substance, cosmos certification is carried out on the raw material, and the functional effect of the raw material is researched, but the extract raw material has the defects of dark color, gradual dark color after the cosmetic finished product is prepared, and high price. The current market products are products prepared by extracting total flavonoids from lotus leaves, or products prepared by separating and purifying flavonol glycosides contained in the lotus leaves by technologies such as multi-step treatment and the like; the treatment has the defects that the product property is unstable, the color is continuously darkened, and the application of raw materials is influenced; or the process steps are multiple, the preparation cost is high, the economic benefit is not good, and meanwhile, the relationship between the product efficacy and the flavonoid substances is deeply researched, so that the development and the application of the lotus leaf extract are limited.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a preparation method and application of a lotus leaf extract.

In order to achieve the purpose, the invention adopts the technical scheme that:

in a first aspect, the present invention provides a method for preparing a lotus leaf extract, comprising the steps of:

(1) screening lotus leaf medicinal materials, selecting lotus leaf medicinal materials which are dried in the sun and cut into long strips from the market. Weighing folium Nelumbinis, coarse crushing or pulverizing, increasing contact area of extraction solvent water and medicinal material tissue, and facilitating fully extracting effective components of flavonoids. Adding water, extracting for 1-3 hours under reflux, wherein the material-liquid ratio of the lotus leaf medicinal material to the water is 1g: 15-30 mL, extracting for 1-3 times, filtering to obtain a total flavone extracting solution, and concentrating the total flavone extracting solution to 0.5-2 times of the weight of the lotus leaf medicinal material to obtain a concentrated solution;

(2) adding an acid solution into the concentrated solution prepared in the step (1), wherein the addition amount of the acid solution accounts for 1-6% of the mass of the concentrated solution, and heating, refluxing and hydrolyzing for 0.5-5h to obtain a hydrolyzed solution;

(3) filtering the hydrolysis solution while the hydrolysis solution is hot, and decoloring the filtrate to obtain a decoloring solution;

(4) drying the decolorized solution to obtain folium Nelumbinis extract.

The preparation process adopts an acid hydrolysis method to hydrolyze flavonoids in lotus leaves to obtain flavonoid aglycone, which is different from that the flavonoid in lotus leaves is not hydrolyzed in domestic common products, so that the antioxidation of the product is improved; in addition, the invention also adopts a decoloring process, so that the color of the decolored product is lighter, and the color is not obviously changed in the placing process, so that the product is darker in color in a way different from the placing process of the lotus leaf extracting solution in the market, and the application of the product in the formula of cosmetics is influenced. The lotus leaf extract is prepared through the steps of extraction, hydrolysis, decoloration and the like, and the prepared product is light and stable in color and has a good antioxidant effect.

Preferably, the material-liquid ratio of the lotus leaf medicinal material to the water solvent is 1g:15 mL. The preparation process adopts the hydrolyzed lotus leaf flavonol glycoside to obtain the flavonoid aglycone, is different from the purification of the lotus leaf total flavone or the purification of one flavonol glycoside in the lotus leaf total flavone in the prior art, also obtains products with stronger antioxidation, does not adopt solvents such as resin purification, ethanol and the like, has less processing steps, and is more beneficial to industrial production.

Preferably, after filtering to obtain a total flavone extract, concentrating the total flavone extract to 0.8-1 time of the weight of the lotus leaf medicinal material. The inventor finds that the acid reflux hydrolysis effect is better when the total flavone extracting solution is concentrated to the range.

Preferably, the acid solution in the step (2) is a sulfuric acid solution with the mass fraction of 98%, the adding amount of the sulfuric acid solution accounts for 1% of the mass of the concentrated solution, and the heating reflux hydrolysis time is 0.5-1.5 h.

Preferably, the acid solution in the step (2) is a hydrochloric acid solution with a mass fraction of 36%, the addition amount of the hydrochloric acid solution is 5% of the mass of the concentrated solution, and the heating reflux hydrolysis time is 3-5 h.

Preferably, activated carbon or decolorizing resin is adopted as a decolorizing agent in the decolorizing treatment in the step (3), and the decolorizing resin is alkaline anionic resin; when the activated carbon is used as a decoloring agent, the using amount of the activated carbon is 1-2% of the mass of the hydrolysis solution, the decoloring temperature is 50-60 ℃, and stirring is carried out for decoloring. The preparation process adopts decolorizing resin or active carbon for decolorizing treatment, and the treated raw materials have no color change in the investigation process, so that the preparation process is favorable for application in cosmetics. The weak alkaline ion resin decoloring process protects the color stability of the product.

Preferably, the step (4) treatment is spray drying or vacuum drying.

In a second aspect, the invention also provides the lotus leaf extract prepared by the preparation method.

In a third aspect, the invention also provides a composition containing the lotus leaf extract, which comprises the following components in percentage by weight: 0.1-1% of lotus leaf extract, 35-45% of butanediol and 55-65% of water.

In a fourth aspect, the invention also provides a lotus leaf extract-containing cosmetic, which comprises the lotus leaf extract-containing composition, wherein the lotus leaf extract-containing composition accounts for 1-3% of the total mass of the cosmetic in percentage by weight. Specifically, the emulsion product comprises the following components in percentage by mass: the composition comprises lotus leaf extract 2%, caprylic/capric triglyceride 3%, mineral oil 3%, isononyl isononanoate 2%, cetearyl alcohol 1%, glycerin 5%, butanediol 5%, sucrose stearate 2%, carbomer 0.15%, 1, 2-hexanediol 0.6%, p-hydroxyacetophenone 0.6%, a proper amount of essence, and the balance of water.

Compared with the prior art, the invention has the beneficial effects that: the preparation process adopts an acid hydrolysis method to hydrolyze flavonoids in lotus leaves to obtain flavonoid aglycone, which is different from that the flavonoid in lotus leaves is not hydrolyzed in domestic common products, so that the antioxidation of the product is improved; in addition, the invention adopts a decoloring process, so that the color of the decolored product is lighter, and the color is not obviously changed in the placing process, so that the product is darker in color in a way different from the placing process of the lotus leaf extracting solution in the market, and the application of the product in the formula of cosmetics is influenced. The lotus leaf extract is prepared through the steps of extraction, hydrolysis, decoloration and the like, and the prepared lotus leaf extract is light and stable in color and has a good antioxidant effect. The lotus leaf extract has good product stability, can remove excessive free radicals and promote skin barrier recovery, and can be used for daily care of various skins.

The product is prepared by extracting folium Nelumbinis total flavonoids with water, preparing flavonoid aglycone by acid hydrolysis, decolorizing to remove pigment impurities, and preparing folium Nelumbinis extract product with strong antioxidation, light and stable color and low cost; can promote the development and utilization of lotus leaf resources in China, improve the economic value of lotus and generate great market benefit.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

Example 1

The preparation method of the lotus leaf extract provided by the embodiment of the invention comprises the following steps:

(1) weighing 100g of lotus leaf medicinal material, and crushing; extracting with water under reflux twice, wherein the water amount is 15 times and 15 times of the weight of folium Nelumbinis respectively, filtering with a fine filter, mixing the two extractive filtrates, and concentrating to weight of about 100 g;

(2) slowly adding 5ml of hydrochloric acid solution with the mass fraction of 36% into the concentrated solution, uniformly mixing, and refluxing for 5 h.

(3) Filtering while hot, decolorizing the filtrate with alkaline anion resin, and collecting the decolorized solution.

(4) Concentrating the decolorized solution, drying to obtain folium Nelumbinis extract, mixing with water and butanediol, and membrane filtering to remove impurities to obtain folium Nelumbinis extract.

Example 2

(1) weighing 100g of lotus leaf medicinal material, and crushing; extracting with water under reflux twice, wherein the water amount is 30 times and 30 times of the weight of folium Nelumbinis respectively, filtering with a fine filter, mixing the two extractive filtrates, and concentrating to weight of about 100 g;

(4) Concentrating the decolorized solution, drying to obtain folium Nelumbinis extract, mixing with water and butanediol, and removing impurities with membrane to obtain folium Nelumbinis extract.

Example 3

(2) slowly adding 1ml of sulfuric acid solution with the mass fraction of 98% into the concentrated solution, uniformly mixing, and refluxing for 1 h.

Example 4

(3) Filtering while hot, adding 0.5% active carbon into the filtrate, stirring at 50 deg.C for decolorizing, and collecting decolorized solution.

Example 5

Comparative example 1

A method for preparing a lotus leaf extract as a comparative example of the present invention comprises the steps of:

(2) filtering while hot, decolorizing the filtrate with alkaline anion resin, and collecting the decolorized solution.

(3) Concentrating the decolorized solution, drying to obtain folium Nelumbinis extract, mixing with water and butanediol, and removing impurities with membrane to obtain folium Nelumbinis extract.

This comparative example is identical to example 1 in that it lacks only the acid hydrolysis step, and the rest of the preparation is identical to example 1.

Comparative example 2

(3) Filtering while hot, concentrating the filtrate, drying to obtain folium Nelumbinis extract, mixing with water and butanediol, and removing impurities with membrane to obtain folium Nelumbinis extract.

Comparative example 2 compared with example 1, only the decoloring step was omitted, and the remaining preparation process was completely the same as example 1.

Comparative example 3

(2) concentrating the decolorized solution, drying to obtain folium Nelumbinis extract, mixing with water and butanediol, and removing impurities with membrane to obtain folium Nelumbinis extract.

Comparative example 3 in comparison with example 1, the acid hydrolysis and decolorization steps were absent and the rest of the preparation process was exactly the same as example 1.

Comparative example 4

(1) weighing 100g of lotus leaf medicinal material, and crushing; extracting with alcohol solution twice under reflux, wherein the alcohol amount is 15 times and 15 times of the weight of folium Nelumbinis, filtering with fine filter, mixing the two extractive filtrates, and concentrating to weight of about 100 g;

Comparative example 4 compared with example 1, the aqueous solution was replaced by an alcoholic solution, and the rest of the preparation process was exactly the same as example 1.

Comparative example 5 is an imported commercially available lotus leaf extract, which is a cosmetic raw material prepared by dissolving and mixing 40% of butanediol as a solvent and 1.5-3.5% of lotus leaf extract powder, and the main effective component is a flavonoid.

Effect example 1

The lotus leaf extracts of the embodiments 1-5 and the comparative examples 1-4 of the invention are prepared into the composition containing the lotus leaf extract, and the composition comprises the following components in percentage by weight: lotus leaf extract 1%, butanediol 39% and water 60%. The compositions containing the lotus leaf extract obtained in examples 1 to 5 and comparative examples 1 to 4 and comparative example 5 were subjected to DPPH radical scavenging test.

1. DPPH free radical scavenging test of compositions containing lotus leaf extract.

The composition containing the lotus leaf extract is subjected to DPPH free radical scavenging measurement, and the national society for daily chemicals industry standard T/SHRH 006-2018 cosmetic-free radical (DPPH) scavenging experimental method is taken as an evaluation method.

TABLE 1 composition containing Nelumbo nucifera leaf extract for DPPH radical scavenging and product color stability

As can be seen from Table 1, compared with comparative example 5, examples 1-5 have slightly higher DPPH radical scavenging rate than comparative example 5, and examples 1-5 have significantly lower IC50 value of DPPH radical scavenging rate than comparative example 5, which indicates that the lotus leaf extract prepared by the invention has stronger radical scavenging ability; comparing examples 1-5 with comparative example 5, one month of accelerated investigation shows that the color of the products of examples 1-5 is unchanged, and the color of the product of comparative example 5 is obviously changed into dark brown, which shows that the lotus leaf extract prepared by the invention has stable color property and is more convenient for subsequent cosmetic preparation application.

Comparative example 1 the composition containing the lotus leaf extract has a lower DPPH free radical clearance than examples 1-5, and mainly has no influence on the clearance effect due to the fact that flavonoid aglycone is prepared by hydrolyzing the lotus leaf total flavonoid glycoside; but the color of the product is not changed in accelerated inspection and is relatively stable.

Comparative example 2 the composition containing lotus leaf extract has a DPPH radical scavenging rate equivalent to that of examples 1 to 5, but the color of the product is accelerated to darken, mainly because the product is not decolorized, which results in oxidative discoloration of the substances in the product and darkening of the color.

Comparative example 3 the compositions containing lotus leaf extract all have lower DPPH radical clearance than examples 1-5, the product color accelerated examination becomes darker, mainly without hydrolysis to produce more strongly oxidized aglycones and without removal of discoloring substances in the product, resulting in relatively low radical clearance of the product and unstable product color.

Comparative example 4 the composition containing lotus leaf extract has a DPPH radical scavenging rate equivalent to that of examples 1-5, and the color accelerated examination of the product has no obvious change, but the preparation cost is obviously higher than that of examples 1-5 by adopting alcoholic solution extraction (the extraction cost is 10 yuan/kg) compared with water extraction (the extraction cost is 6 yuan/kg).

In comprehensive comparison, the lotus leaf extract raw material has stronger free radical scavenging capacity, and the color investigation process of the composition containing the lotus leaf extract is not obviously changed.

Effect example 2

The test process comprises the following steps: the compositions containing the lotus leaf extract prepared in example 1, comparative example 1 and comparative example 2 and comparative example 5 (commercially available lotus leaf extract race) were used to prepare emulsions according to the following formulation:

an emulsion product comprises the following components in percentage by mass: composition containing folium Nelumbinis extract 2%, caprylic/capric triglyceride 3%, mineral oil 3%, isononyl isononanoate 2%, cetearyl alcohol 1%, glycerol 5%, butanediol 5%, sucrose stearate 2%, carbomer 0.15%, 1, 2-hexanediol 0.6%, p-hydroxyacetophenone 0.6%, and water to 100 g.

The preparation method of the emulsion comprises the following steps: (1) accurately weighing caprylic/capric triglyceride, mineral oil, isononyl isononanoate, cetostearyl alcohol and sucrose stearate, mixing, heating to 80-85 ℃, uniformly dispersing, and keeping the temperature for later use; (2) and cooling to 40-45 ℃, heating other raw materials after cooling, and finally adding the lotus leaf extracts prepared in the examples and the comparative examples and uniformly mixing.

The evaluation method comprises the following steps:

first, the emulsion was prepared and placed in an oven at 50 ℃ for 1 month, and the color change before and after the product was recorded.

Secondly, preparing emulsion for human body experiment, and observing the facial skin condition of the volunteers after using the product for evaluation by selecting 40 female volunteers with age of 35-40 years, slightly dark yellow face and severe skin aging, wherein 10 persons in each group and 4 groups in total have no significant difference. Before using the test object, carrying out image acquisition on the skin of the half face of the subject by using a VISIA image analysis system; the test object is used for more than one time after 30 minutes, the test object is used in the morning and evening every day, the fishtail line is used as a standard for testing, the test object is relaxed as much as possible in each test, and the skin in the same area is taken. The skin wrinkle improvement effect was compared between the skin before use and the skin after use for 30 days and 60 days, and each area was measured 3 times and averaged.

TABLE 2 emulsion color at 50 deg.C for 30 days

Ginseng test article	Colour(s)
		Example 1	Without change
Comparative example 1	Without change
		Comparative example 2	Darkening of color
Market contest	Darkening of color

As can be seen from Table 2, the lotus leaf extract has stable color, and the prepared emulsion product has stable color during the standing process; conversely, the emulsion darkens in color. The stability of the lotus leaf extract is related to the stability of a formula product, so that the lotus leaf extract with better stability is prepared, and the application of the lotus leaf extract in cosmetics is facilitated.

TABLE 3 evaluation criteria

Table 4 wrinkle improvement test results

As can be seen from table 4, comparative example 2 of example 1 has a better effect of relieving wrinkles, which is superior to market competitive products; comparative example 1 was the least effective. The emulsion product prepared by adopting hydrolysis and decoloration processes in the embodiment 1 has good and stable effect; comparative example 2 adopts hydrolysis process, and does not decolorize, and the prepared emulsion product has good effect but unstable color; comparative example 1, in which the hydrolysis process was not performed, prepared emulsion products were relatively poor in effect but stable in color despite the decoloring process.

In sum, the lotus leaf extract-containing emulsion can eliminate free radicals, and can lighten wrinkles and delay skin aging after long-term use.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. The preparation method of the lotus leaf extract is characterized by comprising the following steps:

(1) weighing a lotus leaf medicinal material, adding water for reflux extraction, extracting for 1-3 times, filtering to obtain a total flavone extracting solution, and concentrating the total flavone extracting solution to 0.5-2 times of the weight of the lotus leaf medicinal material, wherein the material-liquid ratio of the lotus leaf medicinal material to the water is 1g: 15-30 mL, so as to obtain a concentrated solution;

(4) drying the decolorized solution to obtain folium Nelumbinis extract.

2. The method for preparing lotus leaf extract as claimed in claim 1, wherein the ratio of lotus leaf to water solvent is 1g:15 mL.

3. The method for preparing folium Nelumbinis extract as claimed in claim 1, wherein the total flavone extractive solution is concentrated to 0.8-1 times of folium Nelumbinis medicinal material weight.

4. The preparation method of the lotus leaf extract as claimed in claim 1, wherein the acid solution in the step (2) is a sulfuric acid solution with a mass fraction of 98%, the addition amount of the sulfuric acid solution is 1% of the mass of the concentrated solution, and the heating reflux hydrolysis time is 0.5-1.5 h.

5. The preparation method of the lotus leaf extract as claimed in claim 1, wherein the acid solution in the step (2) is a hydrochloric acid solution with a mass fraction of 36%, the addition amount of the hydrochloric acid solution is 5% of the mass of the concentrated solution, and the heating reflux hydrolysis time is 3-5 h.

6. The method for preparing lotus leaf extract according to claim 1, wherein the decolorization treatment in step (3) uses activated carbon or decolorizing resin as a decolorizing agent, the decolorizing resin being a basic anionic resin; when the activated carbon is used as a decoloring agent, the dosage of the activated carbon is 0.5-2% of the mass of the hydrolysis solution, the decoloring temperature is 50-60 ℃, and stirring is carried out for decoloring.

7. The method for preparing lotus leaf extract according to claim 1, wherein the drying treatment in step (4) is spray drying or vacuum drying.

8. A lotus leaf extract produced by the production method according to any one of claims 1 to 8.

9. A composition containing lotus leaf extract, which is characterized by comprising the lotus leaf extract as claimed in claim 8, and comprises the following components in percentage by weight: 0.1-1% of lotus leaf extract, 35-45% of butanediol and 55-65% of water.

10. A cosmetic containing lotus leaf extract is characterized by comprising the composition containing lotus leaf extract according to claim 9, wherein the composition containing lotus leaf extract accounts for 1-3% of the total mass of the cosmetic in percentage by weight.