Preparation method of low-beany-flavor bean flour and low-beany-flavor soybean formula nutrition powder

Abstract

The invention provides low-beany-flavor bean flour and a preparation method of low-beany-flavor soybean formula nutrition powder, belongs to the field of food processing, and particularly relates to the preparation method of the low-beany-flavor soybean formula nutrition powder. By providing the low-beany-flavor bean flour and the preparation method of the low-beany-flavor soybean formula nutrition powder, the problems that existing soybean formula nutrition powder is inharmonious in amino acid composition, single in nutrition composition, serious in beany flavor and the like are solved. The soybean formula nutrition powder with low beany flavor and balanced nutrition provided by the invention ensures that an organism obtains comprehensive and balanced amino acid combinations, vitamins, minerals and polyunsaturated fatty acids, and the sensitization is also greatly reduced.

Description

Technical Field

[0001] The invention relates to the field of food processing, and in particular to a method for preparing a soybean formula nutrient powder with low beany smell. Background Art

[0002] In modern society, the pace of life is accelerating, work pressure is increasing, and bad habits such as long working hours and staying up late are common, which has led to irregular and unhealthy eating habits, and health problems are becoming increasingly prominent. Therefore, consumers are paying more and more attention to the nutritional value of food, and are looking for products that can provide balanced nutrition to improve their daily diet structure.

[0003] As a high-quality plant protein source, soybeans can significantly improve the protein quality and optimize the amino acid quality in daily diets, especially supplementing essential amino acids such as lysine and tryptophan that are lacking in other cereal proteins. The soluble protein content of soybeans after salt stress germination treatment increased, and functional components such as γ-aminobutyric acid (GABA), ascorbic acid, isoflavones, glutathione and soluble dietary fiber were enriched. In addition, germination treatment accelerated the decomposition of soybean antigen protein and greatly reduced the allergenicity. However, the content of methionine and cystine in soybean protein is relatively low, so the single intake of soybean protein may still have the problem of amino acid imbalance. Therefore, it is very necessary to develop a nutritious soybean functional food.

[0004] And the unpleasant beany smell in soy protein seriously limits its application in food processing. The beany smell is unique to soybeans. At present, in order to remove the beany smell, peeling method, heat treatment method, acid-base method, enzyme method, and microbial fermentation method are often used. However, these methods have various disadvantages. For example, the peeling method cannot remove the lipoxygenase in the soybean cotyledons, the high temperature treatment of the heat treatment method will cause protein denaturation and reduce the yield, the acid-base method requires a strong pH and pollutes the environment, the enzyme method is expensive and cannot be reused, and the microbial method is only for liquid fermented sour soy milk. Therefore, a method for reducing the beany smell of soy protein is urgently needed. Summary of the invention

[0005] The invention solves the problems of unharmonious amino acid composition, single nutritional composition and severe beany smell in the existing soybean formula nutritional powder.

[0006] A method for preparing low beany smell soy flour, the method comprising the following steps:

[0007] S1: Soak the soybeans in NaClO solution for disinfection and then rinse them;

[0008] S2: Add the sterilized soybeans to distilled water and soak them in a 26°C constant temperature box in the dark for 6 hours;

[0009] S3: Place filter paper soaked with NaCl solution on the bottom of the culture dish, add the soaked soybeans, and germinate in a constant temperature and humidity incubator away from light, keeping the filter paper moist during the germination process;

[0010] S4: drying and grinding the germinated soybeans, sieving, and defatting with n-hexane for 3 times to obtain germinated soybean powder;

[0011] S5: adding deionized water to the germinated soybean powder, adjusting the pH to 8.0 with a NaOH solution to obtain a suspension, and ultrasonically treating the suspension to obtain an ultrasonically treated suspension;

[0012] S6: The suspension after ultrasonic treatment is mixed with β-cyclodextrin, and Maillard reaction is carried out in a water bath at pH 9.0 and temperature 55° C. for 3 h to obtain low beany flavor soybean powder.

[0013] Furthermore, the concentration of the NaClO solution in S1 is 1%.

[0014] Furthermore, the amount of distilled water added in S2 is 3 times the mass of soybeans.

[0015] Furthermore, the NaCl solution in S3 is 200 mL of 0.2 M NaCl solution.

[0016] Furthermore, the concentration of germinated soybean powder in the suspension in S5 is 3%.

[0017] Furthermore, the ultrasound in S5 is carried out at a frequency of 20 kHz and an ultrasonic power of 200-600 W for 10-15 min.

[0018] Furthermore, the mixing ratio of the suspension after ultrasonic treatment in S6 and β-cyclodextrin is 5:3 or 1:1.

[0019] A method for preparing a soybean formula nutritional powder with low beany smell, the method comprising:

[0020] S1: mixing spirulina mud with citric acid and breaking the spirulina wall to obtain spirulina powder;

[0021] S2: subjecting the spirulina powder to freeze-thaw extraction, combined enzymatic extraction, hot water extraction, filtration and concentration to obtain the spirulina extract;

[0022] S3: The low beany smell soy powder according to claim 1 is mixed with the spirulina extract in a mass ratio of 5:2, and then sieved, homogenized, and irradiated to obtain a low beany smell and balanced nutritious soy formula nutrient powder.

[0023] Furthermore, the combined enzymatic extraction is performed by hydrolyzing with lysozyme for 2 hours, and then adding amylase, papain, pepsin and trypsin for hydrolysis for 30 minutes to 1 hour respectively.

[0024] A soybean formula nutritious powder with low beany smell is prepared by the method.

[0025] Beneficial Effects

[0026] 1. The method first germinates soybeans (salt stress), which increases the content of soybean soluble protein and makes it easier for human body to absorb; enriches functional components such as γ-aminobutyric acid (GABA), ascorbic acid, isoflavones, glutathione and soluble dietary fiber; accelerates the decomposition of soybean antigen protein and greatly reduces the allergenicity; in addition, the germination process reduces the influence of anti-nutritional factors such as phytic acid and trypsin inhibitors, improves the quality of soybean protein, and facilitates human digestion.

[0027] 2. The soy protein was modified by ultrasonic pretreatment combined with glycosylation reaction, which weakened the binding affinity between the protein structure and the beany substances, thereby reducing the beany smell and increasing its solubility.

[0028] 3. Spirulina is rich in methionine and cysteine ​​that are lacking in soy protein, and contains iron, calcium, magnesium that are lost during the germination of soybeans, as well as polyunsaturated fatty acids and β-carotene. The balanced combination of the two ensures that the body obtains a comprehensive and balanced combination of amino acids, vitamins, minerals and polyunsaturated fatty acids. DETAILED DESCRIPTION

[0029] Example 1. Preparation of nutritional powder.

[0030] 1. Preparation of soybean powder.

[0031] 1kg of selected high-quality soybeans were placed in a 1% (v / v) NaClO solution for disinfection. After rinsing, 3kg of distilled water was added to the cleaned soybeans and soaked in a 26°C constant temperature incubator for 6 hours in the dark. Two layers of filter paper were laid on the bottom of the culture dish, and 200mL of 0.2M NaCl solution was added to completely wet the filter paper. The soybeans were germinated in a constant temperature and humidity incubator at 26°C and 90% humidity for 4 days in the dark; and during the germination process in the dark, water was sprinkled on the surface of the filter paper every 5 hours to keep the two layers of filter paper completely moist.

[0032] The germinated soybeans were dried and powdered, passed through a 60-mesh sieve, and defatted three times with n-hexane. A certain amount of germinated soybean powder was weighed and dissolved in deionized water to prepare a 3% (w / v) suspension, stirred at room temperature for 2 h to fully dissolve it, and the pH was adjusted to 8.0 with a 2M NaOH solution to obtain a suspension.

[0033] Place a beaker containing 3% (w / v) suspension in an ice-water bath, place it in a soundproof box, insert the ultrasonic probe 1.5 cm below the liquid surface, and use 600W ultrasonic power at 20kHz frequency for 15 minutes. Set the ultrasonic parameters: work for 4 seconds, interval for 2 seconds, keep the beaker in an ice-water bath during this period, and control the temperature at around 5°C. After the ultrasonic treatment, place the sample solution in a refrigerator for pre-freezing for 24 hours and then perform vacuum freeze drying to obtain the suspension after ultrasonic treatment.

[0034] The suspension after ultrasonic treatment was mixed with beta-cyclodextrin in a mass ratio of 5:3, and then the Maillard reaction was carried out in a water bath at pH 9.0 and temperature 55°C for 3 hours to remove the beany smell and obtain bean powder.

[0035] 2. Preparation of Spirulina extract.

[0036] Spirulina mud was mixed with 10 mM citric acid (1:1, m / V), placed in an ultrasonic cell disruptor for 10 min at 200 W to break the cell wall, and spirulina powder was obtained for pretreatment.

[0037] Freeze-thaw extraction: Soak Spirulina powder in distilled water (1:1, m / V) and stir magnetically at 40°C for 1 hour. Freeze at -20°C, thaw in a water bath at 35°C, repeat freeze-thaw 4 times, centrifuge at 8000r / min for 10 minutes, obtain freeze-thaw supernatant, which contains Spirulina protein and phycocyanin, and obtain freeze-thaw algae residue.

[0038] Combined enzymatic extraction: add 8 times the mass of distilled water to the frozen and thawed algae residue, add lysozyme and pectinase to hydrolyze for 2 hours. Then add 0.04% amylase, 0.02% papain, 0.06% pepsin, and 0.01% trypsin to hydrolyze for 30 minutes each, centrifuge, obtain the enzymatic supernatant, which contains free amino acids, oligopeptides, oligosaccharides, etc., and obtain the algae residue after enzymatic hydrolysis.

[0039] Hot water extraction: add 10 times the mass of distilled water to the algae residue after enzymatic hydrolysis, stir and extract twice at 80°C, centrifuge and combine the supernatant to obtain the supernatant after hot water extraction, which contains active polysaccharides.

[0040] Filtration and clarification: The freeze-thaw supernatant, enzymatic supernatant and hot water extraction supernatant are combined and initially filtered through a filter to remove large particles and suspended matter. A microporous filter membrane is then used to further remove fine impurities and microorganisms.

[0041] Concentration: The extract is concentrated by reduced pressure evaporation to remove excess water. Pre-freeze at low temperature and then vacuum freeze-dry to obtain spirulina extract rich in functional ingredients such as protein, free amino acids, and active polysaccharides.

[0042] The germinated bean powder after the Maillard reaction is mixed with the spirulina extract in a ratio of 5:2 (m:m), and then sieved, homogenized, and irradiated to obtain a nutritional powder preparation.

[0043] Example 2. Nutritional powders prepared under different conditions.

[0044] 1. Preparation of soybean powder.

[0045] 1kg of selected high-quality soybeans were placed in a 1% (v / v) NaClO solution for disinfection. After rinsing, 3kg of distilled water was added to the soybeans and soaked in a 26°C constant temperature incubator for 4 hours in the dark. Two layers of filter paper were laid on the bottom of the culture dish, and 300mL of 1M NaCl solution was added to completely wet the filter paper. The soybeans were germinated in a constant temperature and humidity incubator at a temperature of 23°C and a humidity of 70% in the dark for 6 days; and during the germination process in the dark, water was sprinkled on the surface of the filter paper every 5 hours to keep the two layers of filter paper completely moist.

[0046] The germinated soybeans were dried and powdered, passed through a 60-mesh sieve, and defatted three times with n-hexane. A certain amount of germinated soybean powder was weighed and dissolved in deionized water to prepare a 3% (w / v) suspension, stirred at room temperature for 2 h to fully dissolve it, and the pH was adjusted to 8.0 with a 2M NaOH solution.

[0047] Place a beaker containing 3% (w / v) suspension in an ice-water bath, place it in a soundproof box, insert the ultrasonic probe 1.5 cm below the liquid surface, and use 200W ultrasonic power at 20kHz frequency for 10 minutes. Set the ultrasonic parameters: work for 4 seconds, interval for 2 seconds, keep the beaker in an ice-water bath during this period, and control the temperature at around 5°C. After the ultrasonic treatment, place the sample solution in a refrigerator for pre-freezing for 24 hours and then perform vacuum freeze drying to obtain the suspension after ultrasonic treatment.

[0048] The suspension after ultrasonic treatment was mixed with β-cyclodextrin in a mass ratio of 1:1, and the Maillard reaction was carried out in a water bath at pH 9.0 and temperature 50°C for 2 h to achieve the purpose of removing the beany smell.

[0049] 2. Preparation of Spirulina extract.

[0050] The spirulina mud and 10 mM citric acid (1:1, m / V) were placed in an ultrasonic cell disruptor for 150 W for 20 min for pretreatment to obtain spirulina powder.

[0051] Freeze-thaw extraction: Soak Spirulina powder in distilled water (1:1, m / V) and stir magnetically at 40°C for 1 hour. Freeze at -20°C, thaw in a water bath at 35°C, repeat freeze-thaw 4 times, centrifuge at 6000r / min for 8 minutes, obtain freeze-thaw supernatant, which contains Spirulina protein and phycocyanin, and obtain freeze-thaw algae residue.

[0052] Combined enzymatic extraction: add 10 times the mass of distilled water to the frozen and thawed algae residue, add lysozyme and pectinase to hydrolyze for 2 hours. Then add 0.04% amylase, 0.02% papain, 0.06% pepsin, and 0.01% trypsin to hydrolyze for 1 hour each, centrifuge, obtain the enzymatic supernatant, which contains free amino acids, oligopeptides, oligosaccharides, etc., and obtain the algae residue after enzymatic hydrolysis.

[0053] Hot water extraction: add 6 times the mass of distilled water to the algae residue after enzymatic hydrolysis, stir and extract twice at 80°C, centrifuge and combine the supernatant to obtain the supernatant after hot water extraction, which contains active polysaccharides.

[0054] Filtration and clarification: The freeze-thaw supernatant, enzymatic supernatant and hot water extraction supernatant are combined and initially filtered through a filter to remove large particles and suspended matter. A microporous filter membrane is then used to further remove fine impurities and microorganisms.

[0055] Concentration: The extract is concentrated by reduced pressure evaporation to remove excess water. Pre-freeze at low temperature and then vacuum freeze-dry to obtain spirulina extract rich in functional ingredients such as protein, free amino acids, and active polysaccharides.

[0056] The germinated bean powder after the Maillard reaction and the spirulina extract are mixed in a ratio of 5:2 (m:m), and then sieved, homogenized, and irradiated to obtain a nutritional powder preparation.

[0057] Example 3. Comparison of different nutritional powders.

[0058] Comparative Example 1: Compared with Example 1, soybeans were germinated by culture in distilled water, and the germination time and other conditions remained unchanged, but no ultrasound-Maillard reaction was performed; the Spirulina extract was consistent with that in Example 1, and the germinated soybean powder and the Spirulina extract were mixed in a ratio of 5:2 (m:m).

[0059] Comparative Example 2: Compared with Example 1, the soybeans were not germinated, but were still subjected to ultrasound-Maillard reaction. The ultrasound parameters were the same as those in Example 1, controlled at 200 W for 10 min. The spirulina extract was consistent with that in Example 1, and the germinated soybean powder and the spirulina extract were mixed in a ratio of 5:2 (m:m).

[0060] Comparative Example 3: Compared with Example 2, soybeans were subjected to salt stress germination treatment, the NaCl concentration was 1 M, and other conditions were consistent with Example 2, but no ultrasound-Maillard reaction was performed; the Spirulina extract was consistent with that in Example 2; the germinated soybean powder and the Spirulina extract were mixed in a ratio of 5:2 (m:m).

[0061] Table 1 Solubility and beany smell of the nutritional powder preparations prepared in Examples 1 and 2 and Comparative Examples 1, 2 and 3.

[0062] Table 1

[0063] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Solubility No caking No caking No caking No caking 5mm agglomerate Beany smell No obvious bean smell Slight bean smell Slight bean smell No obvious bean smell Strong bean smell

[0064] Table 2 Contents of anti-nutritional factors and allergenic proteins of the nutritional powder preparations prepared in Examples 1 and 2 and Comparative Examples 1, 2 and 3.

[0065] Table 2

[0066]

Claims

1. A method for preparing low beany smell soybean powder, characterized in that: The method steps are as follows: S1: Soak the soybeans in NaClO solution for disinfection and then rinse them; S2: Add the sterilized soybeans to distilled water and soak them in a 26°C constant temperature box in the dark for 6 hours; S3: Place filter paper soaked with NaCl solution on the bottom of the culture dish, add the soaked soybeans, and germinate in a constant temperature and humidity incubator away from light, keeping the filter paper moist during the germination process; S4: drying and grinding the germinated soybeans, sieving, and defatting with n-hexane for 3 times to obtain germinated soybean powder; S5: adding deionized water to the germinated soybean powder, adjusting the pH to 8.0 with a NaOH solution to obtain a suspension, and ultrasonically treating the suspension to obtain an ultrasonically treated suspension; S6: The suspension after ultrasonic treatment is mixed with β-cyclodextrin, and Maillard reaction is carried out in a water bath at pH 9.0 and temperature 55° C. for 3 h to obtain low beany flavor soybean powder.

2. The method according to claim 1, characterized in that: The concentration of the NaClO solution in S1 is 1%.

3. The method according to claim 1, characterized in that: S2: The amount of distilled water added is 3 times the mass of soybeans.

4. The method according to claim 1, characterized in that: S3 The NaCl solution is 200 mL of 0.2 M NaCl solution.

5. The method according to claim 1, characterized in that: The concentration of the germinated soybean powder in the suspension in S5 is 3%.

6. The method according to claim 1, characterized in that: The ultrasound in S5 is carried out at a frequency of 20 kHz and a power of 200-600 W for 10-15 min.

7. The method according to claim 1, characterized in that: S6 The mixing ratio of the suspension after ultrasonic treatment and β-cyclodextrin is 5:3 or 1:

1.

8. A soybean formula nutritional powder with low beany flavor, characterized in that: The method is: S1: mixing spirulina mud with citric acid and breaking the spirulina wall to obtain spirulina powder; S2: subjecting the spirulina powder to freeze-thaw extraction, combined enzymatic extraction, hot water extraction, filtration and concentration to obtain the spirulina extract; S3: The low beany smell soy powder according to claim 1 is mixed with the spirulina extract in a mass ratio of 5:2, and then sieved, homogenized, and irradiated to obtain a low beany smell and balanced nutritious soy formula nutrient powder.

9. The method according to claim 8, characterized in that: The combined enzymatic extraction comprises hydrolyzing with lysozyme for 2 hours, and then respectively adding amylase, papain, pepsin and trypsin for hydrolysis for 30 minutes to 1 hour.

10. A soybean formula nutritional powder with low beany smell, characterized in that: The nutritional powder is prepared according to any one of claims 8-9.

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