CN110859223A

CN110859223A - Non-fried cured easy-to-brew coarse grain whole flour and preparation method thereof

Info

Publication number: CN110859223A
Application number: CN201911128441.9A
Authority: CN
Inventors: 迟原龙; 龚川杰; 姚开; 贾冬英
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2020-03-06

Abstract

The invention discloses non-fried cured easy-to-brew coarse grain whole flour and a preparation method thereof, and the non-fried cured easy-to-brew coarse grain whole flour is prepared by mixing 177-250 mu m of tartary buckwheat flour, oat flour, millet flour, 125-177 mu m of black bean flour, red bean flour and 149-177 mu m of purple sweet potato flour. The tartary buckwheat, the oat, the millet, the black bean, the red bean and the purple sweet potato are treated by adopting modes of extrusion puffing, germination accelerating, microwave drying, low-temperature baking and the like, starch gelatinization can be effectively improved, insoluble dietary fibers are promoted to be converted into soluble dietary fibers, glycated protein in food is reduced, and compared with the method for frying raw materials, the tartary buckwheat, the oat, the millet, the black bean, the red bean and the purple sweet potato are completely preserved in nutrition and are not easy to get inflamed. Meanwhile, the raw materials are endowed with specific particle sizes, and the husk of the coarse food grain is reserved. Adding warm water of 5 times, brewing, and making the paste product have the advantages of uniform suspension of insoluble dietary fiber particles, good solubility, good fluidity, easy swallowing, and fine and smooth taste, and is suitable for the middle-aged and the elderly to swallow and digest. The coarse grain whole flour prepared by the invention has rich nutritive value, is suitable for middle-aged and elderly people to eat daily or after sports, and simultaneously utilizes each part of the coarse grain, thereby improving the economic benefit.

Description

Non-fried cured easy-to-brew coarse grain whole flour and preparation method thereof

Technical Field

The invention relates to the technical field of food processing, relates to coarse grain whole powder and a preparation method thereof, and particularly relates to the coarse grain whole powder which is cooked with low heat, rich in nutrient components, rich in dietary fiber, good in solubility, fine and smooth in taste after being brewed, good in fluidity and easy to swallow, and is suitable for middle-aged and elderly people to eat daily or after exercise, and the preparation method thereof.

Background

With the improvement of economic level and living level, a plurality of varieties of meal replacement powder for increasing various nutritional factors and functional elements according to the requirements of different crowds are available on the market. The coarse grain powder is a single or comprehensive reconstituted meal replacement powder product mainly prepared from cereals, beans and potato food materials. Because the dietary fiber content is high, the taste is coarse, residues exist after eating, and people need to rinse mouth, the problem can be solved by adopting superfine grinding and sieving, namely, the coarse grain fine processing. However, if the coarse grains are too fine, the husks rich in nutritional ingredients and functional factors in the coarse grains are screened away, and although the coarse grains have fine and smooth mouthfeel, the nutritional value is greatly reduced. And the caking rate of the coarse grain powder is increased along with the reduction of the granularity, and the smaller the grain size is, the more easy the caking is during the brewing.

In the middle-aged and old people, the cell function and the metabolic capability are reduced, the contents of cholesterol, blood sugar and blood fat are higher, the coarse food grain and the products thereof are required to be properly ingested to control the blood sugar and promote the intestinal tract movement, but the coarse food grain powder is not suitable for the middle-aged and old people to swallow and digest due to the rough characteristic of insoluble dietary fibers and higher viscosity after the conventional brewing. And the coarse grain paste has the function of quenching thirst for middle-aged and elderly people after exercise. Research shows that the pasty product with the viscosity range of 300-800 mPas is most suitable for middle-aged and elderly people to swallow, and the viscosity range is controlled to be 300-600 mPas in consideration of the characteristic of supplementing water after exercise. However, increasing the amount of water used to reduce viscosity during blending tends to cause precipitation and stratification of insoluble dietary fibers in the roughage paste, leading to dispersion problems.

CN108077735A discloses a coarse cereal powder and a preparation method thereof, aiming at different physical and chemical properties of various raw materials, different methods are adopted for pretreatment, and the raw materials are divided into water-soluble starch, fungus powder, plant powder, fruit and vegetable powder, non-water-soluble plant powder and grease plant powder, so that the coarse cereal powder has the advantages of reasonable ingredients, good taste, mellow aroma, strong water solubility, high absorption rate and long shelf life. CN105105023A discloses a germinated health-care coarse cereal powder and its preparation method, which is a formula germinated coarse cereal powder with nutrition and health-care functions suitable for people, prepared by using 15 kinds of coarse cereals as raw materials, germinating through scientific means to enrich various functional components, then formulating according to a proportion, and carrying out processes of puffing, crushing, sieving, blending, packaging and the like. CN105495314A discloses a dietary fiber porous coarse cereal powder, which is prepared by ultrasonically eluting coarse cereal shells by ethanol, adding amylase, saccharomycetes and lactobacillus into peel dregs, mixing and fermenting, thereby not only increasing the nutritive value of the coarse cereals, but also having very strong health care function, simultaneously reasonably utilizing each part of the coarse cereals, making the best use of the matters, reducing the cost to a certain extent and improving the economic benefit.

In the patent, on the basis that the main material is coarse cereals, fruits and vegetables and other substances are added or a probiotic fermentation enriching formula is utilized, so that the formula contains more components, and the product is richer in nutrition compared with single coarse grain powder; or pregermination and other treatments are carried out according to the properties of the raw materials so as to keep the nutrition of the coarse grains, but the problems of dissolubility after brewing and suitability for middle-aged and elderly people are not solved.

Based on the analysis, the coarse grain whole flour which utilizes all parts of the coarse grain, has full starch gelatinization, rich soluble dietary fiber content, low glycated protein content, complete nutrition preservation and difficult ignition, and has uniform suspension of insoluble dietary fiber particles and good solubility after being brewed is urgently needed by the industry.

Disclosure of Invention

By contrast, the present invention is substantially different from the above-disclosed patents. The invention aims to keep the nutrient substances such as coarse grain powder high dietary fiber and the like, and simultaneously ensure that the product has the characteristics of easy brewing, good dispersibility, fine and smooth mouthfeel and suitability for middle-aged and elderly people to eat. The raw material proportion is determined by using a linear programming equation according to the nutrient recommended intake of middle-aged and elderly sports people and the nutrient components of each raw material by using the cereal, bean and potato coarse grains rich in dietary fibers and functional factors as auxiliary materials, wherein the auxiliary materials are skimmed milk powder and xylitol and referring to a Chinese resident dietary nutrient reference Intake Scale (DIRs). Corresponding low-heat curing technologies are selected according to different coarse grain characteristics, and wall breaking and secondary curing are performed by adopting stone grinding, so that the nutrition of the coarse grain is retained to the maximum extent, and the solubility is improved. The physiological function and nutritional requirement of middle-aged and elderly people are researched in food nutrition and fluidics, and by combining the raw material particle size regulation and control technology and the colloid stable dispersion technology, the developed product is rich in nutrition, easy to brew, and good in appearance, taste and fluidity and dispersibility of coarse grains after being brewed, and is suitable for being eaten by the middle-aged and the elderly people after daily life and exercise.

Based on the above analysis, the present invention is realized by the following means:

firstly, linear programming is carried out on the mixture ratio of raw materials to solve:

typically lysine is the first limiting amino acid of cereal proteins, while methionine (a sulfur-containing amino acid) is the first limiting amino acid of most non-cereal plant proteins. In addition, oats lack threonine and millet lacks tryptophan. Beans are one of varieties with the highest protein content in plants, the amino acid composition in the protein is similar to that of egg and milk proteins, except for slightly lower methionine and cystine, the content of other essential amino acids is rich, and the protein is complete vegetal protein; the protein is equivalent to animal protein in nutritive value, and belongs to high-quality protein. Therefore, the beans can be fully utilized and matched with other grains for eating, the condition of lysine deficiency in other grains is compensated, the deficiency of cystine and methionine of the beans is also supplemented by the content of homocystine and methionine in other grain proteins, and the biological value of the beans is obviously improved after the protein complementation effect.

TABLE 1 nutrient composition table of raw materials

。

TABLE 2 dietary nutrient reference intake Scale (DIRs) for Chinese residents

。

According to the analysis of the table 1 and the table 2, the energy intake ratio of breakfast, lunch and dinner on the diet is 3:4:3, the coarse grain whole flour is generally eaten in the morning or evening meal or matched with other foods, the energy is the lowest as a target function, 30% of dietary nutrients provided by 100 g of the product are used as constraint conditions to design a linear equation set, and the planning solution is utilized to obtain a sample, wherein the energy intake ratio of the coarse grain whole flour to the meal is 3:4: 3: 18% of tartary buckwheat, 10% of oat, 11% of millet, 8% of black bean, 15% of red bean, 9% of purple sweet potato, 12% of skimmed milk powder and 17% of xylitol.

Secondly, the problem that insoluble dietary fibers in the coarse grain whole powder are dispersed more stably is solved:

due to the increase of age, the physiological function and the capability of mutual coordination between functions of the middle-aged and the elderly are reduced to different degrees, wherein the reduction of swallowing capability directly influences the diet and nutrition of the middle-aged and the elderly. Rational texture modification of food is considered to be an effective means of improving the quality of life and ensuring safe swallowing in persons with swallowing disorders in the middle and old age. The viscosity of the liquid food is adjusted to avoid out-of-phase. And the timely supplement of water and nutrient substances is also fully ensured, so that the risk of malnutrition is avoided. The liquid food is divided into a thin type (1-50 mPas), a nectar type (51-350 mPas), a honey type (351-1750 mPas) and a pudding type (1750 mPas) in turn by taking an apparent shear hardness value corresponding to a shear rate of 50 r/s at room temperature of 25 ℃ as a standard. Wherein the thick soup-shaped and low-consistency nectar type and the yoghourt-shaped and medium-consistency honey type mixed product is most suitable for the middle-aged and the elderly people to eat. Aiming at the characteristic that water needs to be supplemented after movement, the viscosity range is controlled to be 300-600 mPas.

The invention relates to a processing method of non-stir-fried cured easy-brewing coarse grain whole powder, which comprises the following steps:

cleaning raw materials, removing impurities, soaking, accelerating germination, curing, drying, crushing, blending and packaging to obtain a finished product.

Grain → sifting and removing impurities → crushing → adjusting water content → extruding → drying → crushing → sealing and storing;

beans → cleaning and impurity removal → soaking → accelerating germination → steaming → microwave drying → hot air drying → crushing → sealing → preservation;

purple sweet potato → washing → steaming → chopping mud → low-heat baking → hot air drying → crushing → sealing for preservation.

The method comprises the following specific steps:

1. selecting high-quality tartary buckwheat rice, oat rice and millet, screening out mildewed grains and impurities, crushing, and sieving with a 60-mesh sieve. Adding water into the raw materials, and controlling the moisture by using a rapid moisture tester to enable the moisture content of the fed material to reach 16-18%. The temperature of a machine barrel is set (the temperature of the five zones is respectively 90 ℃, 100 ℃, 110 ℃, 130 ℃ and 165 ℃), the rotating speed of a screw is 140-160 r/min, and the feeding speed is 30 r/min. And after the material is discharged stably, collecting extruded materials to respectively obtain puffed tartary buckwheat grains, oat grains and small rice grains, and drying the extruded products in a thermostat at 50 ℃ for 3 hours. The puffing degree of the product reaches 4-4.3, and the gelatinization degree reaches 85-95%.

2. Selecting high-quality black beans and red beans, cleaning and removing impurities, baking with hot air at 40-45 ℃ for 30 min, soaking at 25 ℃ for 24h, removing excessive water, and accelerating germination at 25 ℃ for 48 h to obtain germinated black beans and red beans. Steaming the mixture for 120min in boiling water at 100 ℃, steaming until the mixture is soft and rotten, and drying the mixture for 6-8 min by using 300-500 w of microwave, wherein the water content is reduced by 50%. Drying the mixture by hot air at 70-75 ℃ to constant weight.

3. Selecting high-quality purple potatoes, cleaning surface soil, steaming the purple potatoes for 40-60 min in boiling water at 100 ℃, steaming the purple potatoes until the purple potatoes are soft and rotten, grinding the purple potatoes into slurry, baking the purple potatoes in an oven at 100-115 ℃ with an upper fire and 120-125 ℃ with a lower fire for 100-120 min, reducing the water content by 40% at the moment, and drying the purple potatoes to constant weight at 70-75 ℃.

4. Pulverizing the cured and dried raw materials by a stone mill pulverizer. The particle size of the pulverized tartary buckwheat powder, the oat powder and the millet powder is 177-250 mu m, the particle size of the black bean powder and the red bean powder is 125-177 mu m, and the particle size of the purple sweet potato powder is 149-177 mu m.

5. In the sample, determined by the linear programming equation: 18 parts of tartary buckwheat, 10 parts of oat, 11 parts of millet, 8 parts of black bean, 15 parts of red bean, 9 parts of purple sweet potato, 12 parts of skimmed milk powder and 17 parts of xylitol. 1-1.5 parts of konjak fine powder.

6. Mixing the raw materials and adjuvants with a food processor, sealing, and storing.

The invention has the beneficial effects that:

1. the method adopts the modes of extrusion puffing, accelerating germination, microwave drying and low-temperature baking to promote the conversion of insoluble dietary fibers into soluble dietary fibers, improve the solubility of the insoluble dietary fibers, furthest retain the nutritional value of the insoluble dietary fibers, prolong the shelf life and improve the utilization rate of nutrients for human bodies.

2. The process can pertinently break the valence bonds between the molecules of the porous sponge-state fiber formed by the raw materials, crack the molecules, and change the polarity of the molecules, thereby promoting the conversion of insoluble dietary fiber to soluble dietary fiber; the molecular structure of the protein is stretched and recombined, the redistribution of surface charges tends to be uniform, and intermolecular hydrogen bonds, disulfide bonds and other parts are broken, so that the protein is finally denatured; other factors such as growth inhibitory factor, lipoxygenase and lipohydrolase are all destroyed, and based on the change in the processing process, the utilization rate of the human body to starch, protein and the like is improved.

3. According to the characteristics of the components of the raw materials, the raw materials are ground to different particle sizes by a traditional stone mill, the husk and the fine particle sizes of the coarse food are reserved, the coarse food is mixed, the coarse food state of the final product is obvious, the color of the food material is reserved to the maximum extent, the glycated protein in the food is reduced, the nutrition is completely preserved, and the raw materials are not easy to get inflamed. The paste is brewed by warm water at 60-80 ℃ with the mass-volume ratio of 1:5 by combining a colloid stable dispersion technology, and insoluble dietary fiber particles in the paste product after brewing are uniformly suspended, so that the paste product has good solubility and fine and smooth mouthfeel, and is suitable for swallowing and digesting by middle-aged and old people.

4. The nutritional food comprises the following raw materials: grains, beans and potatoes which are rich in dietary fiber and have low glycemic index are used as raw materials, and the nutrition of the raw materials is complementary; the auxiliary materials are skimmed milk powder and xylitol, so that the low fat and low sugar content are realized, and the nutritional value of the beverage is improved.

5. According to the physiological characteristics of the middle-aged and the elderly groups with good sports love, the invention develops a coarse food grain powder product which has good fluidity, is easy to swallow and has good taste.

Drawings

FIG. 1 is a solid powder under-mirror representation of various groups of examples and commercial samples;

FIG. 2 shows the results of sensory evaluation of solid powders for each set of examples and commercial samples.

Detailed Description

The number of examples is 10.

Example 1: taking 18 parts of tartary buckwheat powder with the particle size of 250 microns, 10 parts of oat powder with the particle size of 250 microns, 11 parts of millet powder with the particle size of 250 microns, 8 parts of black bean powder with the particle size of 177 microns, 15 parts of red bean powder with the particle size of 177 microns, 9 parts of purple sweet potato powder with the particle size of 177 microns, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.5 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 2: taking 18 parts of tartary buckwheat powder with the particle size of 177 micrometers, 10 parts of oat powder with the particle size of 177 micrometers, 11 parts of millet powder with the particle size of 250 micrometers, 8 parts of black bean powder with the particle size of 125 micrometers, 15 parts of red bean powder with the particle size of 177 micrometers, 9 parts of purple sweet potato powder with the particle size of 149 micrometers, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.25 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 3: taking 18 parts of tartary buckwheat powder with the particle size of 250 microns, 10 parts of oat powder with the particle size of 250 microns, 11 parts of millet powder with the particle size of 177 microns, 8 parts of black bean powder with the particle size of 177 microns, 15 parts of red bean powder with the particle size of 149 microns, 9 parts of purple sweet potato powder with the particle size of 149 microns, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.5 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 4: taking 18 parts of tartary buckwheat powder with the particle size of 177 micrometers, 10 parts of oat powder with the particle size of 250 micrometers, 11 parts of millet powder with the particle size of 177 micrometers, 8 parts of black bean powder with the particle size of 149 micrometers, 15 parts of red bean powder with the particle size of 177 micrometers, 9 parts of purple sweet potato powder with the particle size of 177 micrometers, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.5 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 5: taking 18 parts of tartary buckwheat powder with the particle size of 250 microns, 10 parts of oat powder with the particle size of 177 microns, 11 parts of millet powder with the particle size of 177 microns, 8 parts of black bean powder with the particle size of 177 microns, 15 parts of red bean powder with the particle size of 149 microns, 9 parts of purple sweet potato powder with the particle size of 177 microns, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.3 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 6: taking 18 parts of tartary buckwheat powder with the particle size of 177 microns, 10 parts of oat powder with the particle size of 250 microns, 11 parts of millet powder with the particle size of 250 microns, 8 parts of black bean powder with the particle size of 125 microns, 15 parts of red bean powder with the particle size of 125 microns, 9 parts of purple sweet potato powder with the particle size of 149 microns, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.4 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 7: taking 18 parts of tartary buckwheat powder with the particle size of 250 microns, 10 parts of oat powder with the particle size of 250 microns, 11 parts of millet powder with the particle size of 250 microns, 8 parts of black bean powder with the particle size of 149 microns, 15 parts of red bean powder with the particle size of 149 microns, 9 parts of purple sweet potato powder with the particle size of 177 microns, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.25 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 8: taking 18 parts of tartary buckwheat powder with the particle size of 177 micrometers, 10 parts of oat powder with the particle size of 177 micrometers, 11 parts of millet powder with the particle size of 250 micrometers, 8 parts of black bean powder with the particle size of 177 micrometers, 15 parts of red bean powder with the particle size of 149 micrometers, 9 parts of purple sweet potato powder with the particle size of 177 micrometers, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.3 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 9: taking 18 parts of tartary buckwheat powder with the particle size of 250 microns, 10 parts of oat powder with the particle size of 177 microns, 11 parts of millet powder with the particle size of 250 microns, 8 parts of black bean powder with the particle size of 149 microns, 15 parts of red bean powder with the particle size of 125 microns, 9 parts of purple sweet potato powder with the particle size of 149 microns, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.4 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Example 10: taking 18 parts of tartary buckwheat powder with the particle size of 177 micrometers, 10 parts of oat powder with the particle size of 177 micrometers, 11 parts of millet powder with the particle size of 177 micrometers, 8 parts of black bean powder with the particle size of 125 micrometers, 15 parts of red bean powder with the particle size of 125 micrometers, 9 parts of purple sweet potato powder with the particle size of 149 micrometers, 12 parts of skimmed milk powder and 17 parts of xylitol. 1.5 parts of konjak fine powder, uniformly mixing by using a food processor, and sealing.

Test example 1

The indexes of the coarse grain whole powder of each group of examples and comparative examples are measured

Total dietary fiber and soluble dietary fiber

The dietary fiber is divided into soluble dietary fiber according to physicochemical properties such as water solubility and gel forming propertyWei (A)Soluble Dietary FibreSDF for short and insoluble dietary fiber: (Insoluble Dietary FibreIDF for short). The significance of the physiological function of dietary fiber is strongly related to the ratio of SDF to IDF. SDF can ferment in intestinal tract, increase viscosity of intestinal tract substance, relieve constipation, prevent and treat cholelithiasis, eliminate harmful metal ions, reduce serum and liver cholesterol, inhibit postprandial blood sugar increase, prevent hypertension and heart disease, etc., while IDF can reduce digestion rate, increase feces amount, and prevent obesity, constipation, colon cancer, etc. Thus, SDF has better physiological activity than IDF.

The content of total dietary fiber and soluble dietary fiber in the coarse grain whole powder is measured according to the method of GB 5009.88-2014 'determination of dietary fiber in national standard food for food safety'.

Degree of gelatinization

Starch is insoluble in water at normal temperature, but when the water temperature is above 53 ℃, the physical properties of the starch are obviously changed. The characteristic of starch that swells and splits at high temperature to form a homogeneous pasty solution is called gelatinization of starch. And measuring the gelatinization degree of the product by adopting a spectrophotometry method. After a series of treatments, the absorbance of the sample and the absorbance of the fully gelatinized sample were measured with a spectrophotometer at 420 nm, respectively. The formula is as follows:

。

dietary fiber and gelatinization indicators for each group of samples are shown in table 3:

TABLE 3 dietary fiber and gelatinization index of sample

。

The content of soluble dietary fibers in the grains is 25-30% of the total dietary fibers, the breakage of polysaccharide glycosidic bonds is caused by mechanical shearing force in the extrusion processing process, more oligosaccharides are released, and the conversion from insoluble dietary fibers to soluble dietary fibers is carried out, so that the content of the soluble dietary fibers is increased. According to the results in table 3, the total dietary fiber content and the soluble dietary fiber content of the coarse food grain whole powder are obviously higher than those of similar products sold in the market, and the coarse food grain whole powder belongs to food rich in dietary fiber.

The grains contain a large amount of starch, and the starch can be gelatinized by extruding, puffing and stone grinding and secondary curing, so that the dissolubility of the coarse grain whole powder is improved. The gelatinization degree of the coarse grain whole flour starch is higher than that of similar products sold in the market, so that the solubility is better, and more nutrition can be absorbed and utilized by human bodies.

Tri, gamma-aminobutyric acid

Glutamic Acid Decarboxylase (GAD) is the only enzyme catalyzing the decarboxylation of glutamic acid to generate gamma-aminobutyric acid, the activity of the GAD is high and low, the germination capacity, the emergence rate and the like of seeds are measured, and the activity of the GAD can be reflected more visually by measuring the generation amount of the product gamma-aminobutyric acid. The gamma aminobutyric acid content of each set of samples is shown in table 4:

TABLE 4 sample gamma-aminobutyric acid content

。

According to the results in table 4, it can be seen that the gamma-aminobutyric acid content of the beans after the pregermination treatment is significantly higher than that of the non-pregerminated samples. After the germination accelerating treatment, the nutritive value of the fertilizer is greatly improved.

Fourth, microscopic examination (10 is multiplied by 10)

0.1 g of the uniformly mixed powder of each group was uniformly spread on a glass slide, and the microstructure of the surface of the sample was observed by an optical microscope and photographed, and the result under the solid powder microscope is shown in FIG. 1.

It can be observed from the results of fig. 1 that the coarse grain whole flour products of examples 1-10 were coarsely mixed and the rich hull was retained. The dietary fiber is micronized and arranged orderly, which not only can improve the taste, but also can break chemical bonds therein, thereby increasing the contact with water molecules and leading some insoluble dietary fibers to become water-soluble. While the dietary fibers of the two commercial groups of roughage powders were not micronized and were dispersed in the distribution, especially the commercial 2 roughage powder performed the least. The formula and the process of the invention are adopted to prepare the coarse grain whole powder, which has outstanding performance on the capability of converting insoluble dietary fiber into soluble dietary fiber.

Test example 2

Various indexes of coarse grain after whole flour mixing

Taking the prepared coarse grain whole powder, brewing with warm water at 60-80 ℃ with the mass-volume ratio of 1:5, and measuring the properties of the coarse grain whole powder after brewing, such as viscosity, solubility index and the like.

Viscosity of

Weighing 5 g of sample by using an analytical balance, adding 25 mL of 80 ℃ hot water to prepare coarse grain paste with the mass fraction of 20%, fully stirring for 10min, and then standing for 10 min. And selecting a proper rotor, measuring the viscosity of the mixture by using an NDJ-5S type viscometer, and reading and recording data after 30 seconds.

Second, caking rate

Weighing 20 g of coarse grain whole powder in a beaker, adding 100 mL of hot water at 80 ℃, simulating the stirring speed of a human, and observing the phenomena of caking and delamination after stirring for 1 min at 200 r/min by a magnetic stirrer; and (3) filtering the coarse grain paste by using a 20-mesh screen, washing the agglomerates with clear water, putting the agglomerates into a drying oven, drying to constant weight, weighing the agglomerates with the screen, and subtracting the weight of the screen to obtain the weight of the agglomerates. The blocking rate is calculated as follows:

。

tri, dispersivity

Dispersibility refers to the property that some solid particle groups can be suspended in some homogeneous medium, such as water, to disperse into small particles without forming precipitates. The dispersion index is used in this experiment to indicate the difference in dispersion. Weighing about 5 g of coarse grain whole powder, accurately measuring to 0.01 g, recording the mass, placing in a 100 mL beaker, weighing 30 mL of 80 ℃ deionized water, adding the deionized water, stirring for 1 min at 500 r/min on a magnetic stirrer at 80 ℃, standing for 5 min, and adding 30 mL of 80 ℃ deionized water again for dilution. The diluted sample was screened through a 20 mesh screen, carefully rinsed with distilled water and the unscreened cake left on the screen was collected and placed in an oven at 105 ℃ to dry to constant weight. Three replicates were performed to reduce experimental error.

The dispersion index is calculated according to the formula as follows:

。

wherein: m is the mass of the dried caking, and the unit is g;

m is the total mass of the sample, and the unit is g;

w is the moisture content of the sample.

The evaluation criteria for the dispersibility index are: a dispersion index of more than 95% is very good, preferably 90% to 95%, more preferably 80% to 90%, and less preferably less than 80%.

Fourth, wettability

Wettability is a quality standard index of a wettable powder sample, and is expressed by spraying a certain amount of sample on a water surface and measuring the time for which the powder is completely wetted, namely a wettability index. Firstly, 100 mL of distilled water with the temperature of 30 ℃ is added into a 250 mL beaker for standby, and about 1 g of coarse grain whole powder is accurately weighed to be accurate to 0.01 g. A standard sieve of 60 meshes is placed above a beaker, weighed sample powder is carefully poured into the middle of the sieve, and a stopwatch is started to count time, so that the sieve is slightly flicked to enable the sample to be rapidly contacted with the water surface. The time was recorded when the powder of the sample subsided or had only a small amount of water floating but had a wet appearance, i.e., the particles considered to be sample powder were soaked with water. To reduce the test error, the test was performed in triplicate. The wettability was considered to be very good when the wetting time was 10 seconds or less, good when the wetting time was between 10 seconds and 30 seconds, general when the wetting time was between 30 seconds and 60 seconds, poor when the wetting time was between 60 seconds and 120 seconds, and very poor when the wetting time was 120 seconds or more.

Fifthly, stability of brewing

Weighing 5 g of prepared coarse grain whole powder, pouring the weighed coarse grain whole powder into a 50 mL clean beaker, adding 45 mL of distilled water at 80 ℃, stirring at the speed of 500 r/min for 1 min to form a uniform suspension, transferring the suspension into a 100 mL measuring cylinder, and standing for 10 min. The height of the suspension and the height of the supernatant were observed and recorded.

。

Wherein: h1 is the height of the supernatant;

h2 is the total height of the suspension.

The evaluation criteria of the brewing stability are as follows: the stability index is excellent at less than 5, preferably between 5 and 10, less preferably between 10 and 20, and very poor at more than 20.

VI Water absorption index and Water solubility index

Water Absorption Index (WAI) and Water Solubility Index (WSI) are the functional indexes of the product, and WAI is the volume occupied by starch particles and starch polymer after swelling in excessive Water; while WSI measures the amount of free polysaccharide or polysaccharide released from starch granules upon addition of excess water. In order to make the coarse grain whole powder have good swelling property and dispersibility, the WAI and WSI of the product are required to be improved as much as possible. Putting 1 g of sample into a weighed centrifuge tube with a cover, adding 30 mL of water, violently shaking to uniformly disperse the sample in the water, placing the centrifuge tube in a water bath at 30 ℃, shaking once every 5 min to maintain the suspension state of sample powder as much as possible, and taking out the centrifuge tube after 30 min. The WSI of the supernatant was determined by centrifugation at 4000 r/min for 30 min, and the WAI of the precipitate was determined.

Wherein M is₁G, the mass of the precipitate after centrifugation; m₂Is the dry matter mass of the supernatant. M is the mass of the sample.

The washout index for each group of samples is shown in table 5:

TABLE 5 Impulse performance index for each group of samples

。

After the coarse grain whole powder is conventionally blended into paste, the viscosity of the paste is 300-600 mPa & s, under the same blending mode, the viscosity of the paste of the similar products sold in the market is higher than that of the coarse grain paste, the paste is too thick, the paste is not suitable for being eaten by middle-aged and old people after sports, and the phenomenon of cup hanging and the like is easy to occur. The invention has low caking rate, very good dispersibility, quick wetting during brewing and excellent stability, forms uniform suspension after brewing, has good swelling property with a commercially available sample, and has better water solubility and dispersibility than the commercially available sample.

Seventh, sensory evaluation

And respectively organizing 20 food sensory evaluation personnel with sports hobbies and interested in the coarse grain paste at the age of 60-75 years to form a sensory evaluation group, and performing sensory evaluation on 10 products brewed by the coarse grain whole flour. The assessment time was set at the end of the morning at 9:00 am and the mouth was rinsed before the next sample was tasted. And (3) coding the sample by adopting a random number table, flushing the whole coarse grain powder with water of 80 ℃, uniformly stirring, grading the appearance, color, smell, solubility and taste of the soaked coarse grain paste by sensory evaluation personnel, and comparing the dissolvability and taste with similar products sold in the market. The evaluation index is shown in table 6, and the specific scoring results are shown in table 7 and fig. 2:

TABLE 6 sensory evaluation chart

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TABLE 7 sensory evaluation of the samples of each group

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As can be seen from the results of table 7 and fig. 2, the roughage flour of the present invention, when conventionally blended into a paste, has a higher sensory quality than similar products available on the market. Especially in the aspects of solubility and taste, the agglomeration phenomenon of the coarse grain powder products during the mixing is greatly improved, the coarse grain powder is easy to dissolve, is stable and uniform paste after being dissolved, and has obvious coarse grain state. Has certain fluidity, is convenient to eat by sucking with a straw or directly pouring for drinking, has fine and smooth taste without obvious powdery feeling and granular feeling, and has good palatability.

In conclusion, only under the process and the formula of the invention, the coarse grain whole powder with high starch gelatinization degree, rich content of soluble dietary fiber, low content of glycated protein in food, uniform suspension of insoluble dietary fiber particles in a paste product after being brewed and good solubility can be prepared.

The description and applications of the invention herein are illustrative and are not intended to limit the scope of the invention to the embodiments described above. Variations and modifications of the embodiments disclosed herein are possible, and alternative and equivalent various components of the embodiments will be apparent to those skilled in the art. It will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, and with other components, materials, and parts, without departing from the spirit or essential characteristics thereof. Other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.

Claims

1. The non-fried cured easy-brewing coarse grain whole flour is characterized by being prepared from the following raw materials in parts by weight: 18 parts of tartary buckwheat powder, 10 parts of oat powder, 11 parts of millet powder, 8 parts of black bean powder, 15 parts of red bean powder, 9 parts of purple sweet potato powder, 12 parts of skim milk powder, 17 parts of xylitol and 1-1.5 parts of konjac powder.

2. The coarse grain whole flour as claimed in claim 1, wherein the particle size of the tartary buckwheat flour, the oat flour and the millet flour is 177-250 μm, the particle size of the black bean flour and the red bean flour is 125-177 μm, and the particle size of the purple sweet potato flour is 149-177 μm.

3. A method of preparing the non-pan-fried, cured, easy-brew whole roughage flour according to claim 1 or 2, comprising the steps of:

crushing high-quality tartary buckwheat, oat grains and millet, sieving the crushed high-quality tartary buckwheat, oat grains and millet through a 60-mesh sieve, adding water into the raw materials, adjusting the temperature of a machine barrel, the rotating speed of a screw and the feeding speed, collecting extruded materials after discharging is stable, respectively obtaining puffed tartary buckwheat grains, oat grains and small rice grains, and drying the extruded products for later use;

selecting high-quality black beans and small red beans, cleaning and removing impurities, baking by hot air, soaking at room temperature, draining water, and respectively carrying out germination accelerating treatment on the black beans and the small red beans to obtain germinated black beans and small red beans; steaming with boiling water until soft, taking out, microwave drying to reduce water content, and drying in hot air oven to constant weight;

selecting high-quality purple sweet potatoes, cleaning, steaming the purple sweet potatoes in boiling water until the purple sweet potatoes are soft and rotten, grinding the purple sweet potatoes into slurry, baking the purple sweet potatoes in an oven to reduce the moisture, and then drying the purple sweet potatoes to constant weight for later use;

pulverizing the above cured and dried raw materials with stone mill pulverizer, mixing the raw materials and adjuvants with processor, sealing and storing.

4. The preparation method according to claim 3, wherein the moisture content of the raw material in the step (1) reaches 16-18%, the barrel temperature is adjusted according to five temperatures respectively, and the temperatures are sequentially 90 ℃, 100 ℃, 110 ℃, 130 ℃ and 165 ℃, the screw rotation speed is 140-160 r/min, the feeding speed is 30 r/min, and the drying is performed in a 50 ℃ incubator for 3 hours.

5. The preparation method of claim 3, wherein the product obtained in the step (1) has a swelling degree of 4-4.3 and a gelatinization degree of 85-95%.

6. The preparation method according to claim 3, wherein the hot air baking temperature in the step (2) is 40-45 ℃, and the baking time is 30 min; the warm water soaking temperature is 25 ℃, and the soaking time is 24 hours; the germination accelerating temperature is 25 ℃, and the germination accelerating time is 48 hours; the microwave drying power is 300-500 w, and the drying time is 6-8 min; the hot air drying temperature is 70-75 ℃.

7. The preparation method according to claim 3, wherein the baking time in the oven in the step (3) is 100-120 min, the temperature of the upper fire is 100-115 ℃, and the temperature of the lower fire is 120-125 ℃; the drying temperature is 70-75 ℃.

8. The preparation method according to claim 3, wherein the particle size of the tartary buckwheat flour, the oat flour and the millet flour in the step (4) is 177-250 μm, the particle size of the black bean flour and the red bean flour is 125-177 μm, and the particle size of the purple sweet potato flour is 149-177 μm.

9. The non-fried cured easy-brewing coarse grain whole powder prepared by the preparation method of any one of claims 3 to 8.

10. The use method of the non-fried cured easy-brewing coarse grain whole flour as claimed in claim 9, wherein the coarse grain whole flour is brewed with warm water at 60-80 ℃ at a mass-to-volume ratio of 1: 5.