Preparation method of soybean germ fermented soybean milk with high retention rate

Abstract

According to the preparation method, active substances such as soybean germs are enriched through germination, protein is decomposed in advance by adopting enzymolysis fermentation, the fermentation time can be effectively shortened, the viable count and the conversion rate of a target product are increased, the fermentation efficiency is improved by using a compound strain, and the yield of the soybean germs is increased. And combined isoflavone is converted into aglycone with higher bioavailability, and finally, ultrahigh-pressure non-thermal sterilization is used, so that the nutrition, color and flavor of the product are reserved. Compared with the prior art, the method has the advantages that the production process is optimized, the combination of specific strains and fermentation conditions is adopted, the content of soybean isoflavone aglycones in soybean germs is reserved to the maximum extent, meanwhile, part of glycoside is efficiently converted into high-activity aglycones, and meanwhile, the loss of total isoflavone is reduced to the minimum; the aglycone form with higher bioavailability is generated through fermentation, and meanwhile, the product is rich in probiotics and metabolites thereof, so that the nutritional value of the product is more complete.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fermented soy milk preparation, in particular to a preparation method of high-retention soy germ fermented soy milk. BACKGROUND

[0002] Soybean products have a long history in China. They are not only nutritious but also have important health benefits. Soybeans are rich in phospholipids and soy isoflavones. Soybean phospholipids can enhance tissue function, lower cholesterol, improve lipid metabolism, and prevent and treat cerebral and coronary artery sclerosis. They also contribute to liver health and have some therapeutic effects on hepatitis and fatty liver. In addition, soybean phospholipids can promote the absorption of fat-soluble vitamins and prevent the acidification of the body and various tissues and organs. Soy isoflavones have anticancer, anticancer, and antiosteoporosis effects in postmenopausal women. Fermented soy milk is a beverage made by fermenting soybeans with lactic acid bacteria. It has the following advantages: improved nutritional value: the fermentation process improves the flavor of soy milk and increases its nutritional content, such as protein and vitamins. Functional ingredients: fermented soy milk contains rich functional ingredients that can enhance immunity and antioxidant capacity. Market products: there are various fermented soy milk products on the market, such as Bean Bean Plant Yogurt and Farmer's Spring Plant Yogurt. The total content of soy isoflavone aglycone in existing finished soy milk is low, and some are lost during the preparation process, resulting in a decrease in the nutritional value of the finished fermented soy milk. SUMMARY

[0003] In view of the problems existing in the prior art, the present application discloses a preparation method of high-retention soy germ fermented soy milk, comprising the following steps, Step one: take fresh and plump soybeans, wash them, and soak them in water for 8-10 hours. Then take them out and put them in a germinator at 20-25℃, and water them 2-3 times a day to ensure that the soil moisture content is 18-20%. Step two: take the germinated soybeans and soak them in a 0.2-0.4% NaHCO3 solution for 4-8 hours. Then add hot water at a weight ratio of 1:5 to 1:8 to grind the soybeans. After passing through a 300-mesh filter and then a 200-mesh filter, fine soy milk is obtained. Step three: add protease and enzymatically hydrolyze for 2-4 hours at 40-55℃. Then add a stabilizer and sterilize at high temperature. After cooling to room temperature, inoculate with a composite strain and ferment at 35-40℃ for 72 hours. The composite strain is a mixture of Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus plantarum at a ratio of 2:1:1. Step four: after fermentation, centrifuge at 3000r / min for 60s, and then pass through a high-pressure homogenizer at 70-90℃ and 20-23MPa. Step five, after high pressure homogenization is completed at 200 MPa, the finished product fermented soy milk is obtained after high pressure sterilization for 15 minutes.

[0004] As a preferred technical solution of the present application, in step one, the germination rate of the selected soybean is not less than 90%, the water content is not higher than 13%, and the soil temperature in the germination device is not less than 10℃.

[0005] As a preferred technical solution of the present application, in step one, the temperature of the clean water used for soaking is 40-45℃, and after cooling to room temperature, the soybeans are soaked for another 4 hours, and then the clean water is replaced and the soybeans are soaked again.

[0006] As a preferred technical solution of the present application, in step two, the length of the germinated soybean embryo is not more than 1 cm, and the germination time is not more than 48 hours.

[0007] As a preferred technical solution of the present application, in step three, the added protease is 0.02-0.04% of the total weight of the fine soy milk.

[0008] As a preferred technical solution of the present application, in step three, the stabilizer can be selected from one of lotus root powder, pectin, and soybean polysaccharide, and white granulated sugar and glucose can be added in a ratio of 2:1 while adding the stabilizer.

[0009] As a preferred technical solution of the present application, in step three, the inoculation amount of the compound strain is 3-4%, and after fermentation for 4-6 hours, the pH value is detected to be 4.5±0.1.

[0010] The present application has the following advantages: the production process is optimized, specific strains and fermentation conditions are combined, the content of soybean isoflavone aglycone in the soybean embryo is maximally retained, part of the glycosides is efficiently converted into high-activity aglycone, the total isoflavone loss is minimized, the fermented soy milk is rich in prebiotics and their metabolites, and the nutritional value is more complete. DETAILED DESCRIPTION

[0011] Example 1

[0012] The present application discloses a preparation method of fermented soy milk with high retention rate of soybean embryo nutrients, comprising the following steps, Step one, take fresh and full-grain soybeans, wash them and soak them in clean water for 8 hours, then take them out and put them into a germination device, germinate them at 20℃, and water them twice a day to ensure that the soil water content is 18%; Step two, take the germinated soybeans and peel them, soak them in a 0.2% NaHCO3 solution for 4 hours, then add hot water according to a weight ratio of 1:5 to grind the soybeans into a fine soy milk, pass the fine soy milk through a 300-mesh filter and then through a 200-mesh filter to obtain the fine soy milk; Step three, add protease and enzymolysis for 2 hours under 40℃ adjustment, then add stabilizer and high-temperature sterilization, cool to room temperature, inoculate complex strains for fermentation, the complex strains are Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus plantarum mixed in a ratio of 2:1:1, and fermentation is carried out under 35℃ adjustment for 72 hours; Step four, after fermentation, centrifugation is carried out at a speed of 3000r / min for 60s, and then high-pressure homogenization is carried out at 70℃ and 20MPa. Step five, after high-pressure homogenization, high-pressure sterilization is carried out at 200MPa for 15 minutes, and then the finished product fermented soy milk is obtained.

[0013] Example 2

[0014] The application discloses a preparation method of high-retention-rate soy germ fermented soy milk, and comprises the following steps. Step one, fresh granular and plump soybeans are taken, soaked in clean water for 10 hours, and then placed in a germinator for germination under the condition of 25℃, and water is poured 3 times a day to ensure that the soil moisture content is 20%; Step two, the germinated soybeans are peeled, soaked in a 0.4% NaHCO3 solution for 8 hours, hot water is added in a weight ratio of 1:8 for milling, and then passed through a 300-mesh filter and a 200-mesh filter to obtain fine soy milk; Step three, protease is added and enzymolysis is carried out for 2-4 hours under 55℃ adjustment, then stabilizer is added and high-temperature sterilization is carried out, and then complex strains are inoculated for fermentation after cooling to room temperature, the complex strains are Lactobacillus plantarum, Lactobacillus paracasei and Lactobacillus plantarum mixed in a ratio of 2:1:1, and fermentation is carried out under 35-40℃ adjustment for 72 hours; Step four, after fermentation, centrifugation is carried out at a speed of 3000r / min for 60s, and then high-pressure homogenization is carried out at 90℃ and 23MPa. Step five, after high-pressure homogenization, high-pressure sterilization is carried out at 200MPa for 15 minutes, and then the finished product fermented soy milk is obtained.

[0015] Example 3

[0016] The application discloses a preparation method of high-retention-rate soy germ fermented soy milk, and comprises the following steps. Step one, fresh granular and plump soybeans are taken, soaked in clean water for 8 hours, and then placed in a germinator for germination under the condition of 25℃, and water is poured 2 times a day to ensure that the soil moisture content is 20%; Step two, the germinated soybeans are peeled, soaked in a 0.2-0.4% NaHCO3 solution for 4-8 hours, hot water is added in a weight ratio of 1:5 for milling, and then passed through a 300-mesh filter and a 200-mesh filter to obtain fine soy milk; Step three, add protease and enzymolysis for 2 hours under 55℃ adjustment, then add stabilizer, high temperature sterilization, cool to room temperature, inoculate complex strain fermentation, complex strain is lactobacillus plantarum, paracasei lactobacillus, lactobacillus plantarum is mixed according to 2:1:1, ferment for 72 hours under 35℃ adjustment; Step four, after fermentation, centrifuge for 60s at 3000r / min, then put into high pressure homogenizer under 90℃, 20MPa condition for high pressure homogenization; Step five, after high pressure homogenization, high pressure sterilization for 15 minutes under 200MPa, then get finished product fermented soy milk.

[0017] The components not described in detail herein are prior art.

[0018] Although the specific embodiments of the present application have been described in detail above, the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application, and modifications or changes without creative labor are still within the protection scope of the present application.

Claims

1. A method for preparing fermented soybean milk with high retention rate of soybean germ protein, characterized in that: Includes the following steps, Step 1: Take fresh, plump soybeans, wash them, and soak them in clean water for 8-10 hours. After soaking, place them in a germination device and germinate them at 20-25℃. Water them 2-3 times a day to ensure the soil moisture content is 18-20%. Step 2: Peel the sprouted soybeans, soak them in a 0.2-0.4% NaHCO3 solution for 4-8 hours, then add hot water at a weight ratio of 1:5 to 1:8 and grind them into a paste. Filter the paste through a 300-mesh sieve and then through a 200-mesh sieve to obtain a smooth soy milk. Step 3: Add protease and hydrolyze at 40-55℃ for 2-4 hours. Then add stabilizer and sterilize at high temperature. After cooling to room temperature, inoculate with compound bacteria for fermentation. The compound bacteria is a mixture of Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus plantarum in a ratio of 2:1:

1. Ferment at 35-40℃ for 72 hours. Step 4: After fermentation, place the mixture in a centrifuge at 3000 r / min for 60 s, and then place it in a high-pressure homogenizer for high-pressure homogenization at 70-90℃ and 20-23 MPa. Step 5: After high-pressure homogenization, sterilize at 200MPa for 15 minutes to obtain the finished fermented soy milk.

2. The method for preparing fermented soybean milk with high retention rate of soybean germ protein according to claim 1, characterized in that: In step one, the selected soybeans have a germination rate of no less than 90%, a moisture content of no more than 13%, and a soil temperature in the germinator of no less than 10°C.

3. The method for preparing fermented soybean milk with high retention rate of soybean germ protein according to claim 1, characterized in that: In step one, the temperature of the water used for soaking is 40-45℃. After cooling to room temperature, soak for 4 hours, then change the water and repeat the soaking process.

4. The method for preparing fermented soybean milk with high retention rate of soybean germ protein according to claim 1, characterized in that: In step two, the length of the germinated soybean germ should not exceed 1 cm, and the germination time should not exceed 48 hours.

5. The method for preparing fermented soybean milk with high retention rate of soybean germ protein according to claim 1, characterized in that: In step three, the added protease is 0.02-0.04% of the total weight of the refined soy milk.

6. The method for preparing fermented soybean milk with high retention rate of soybean germ protein according to claim 1, characterized in that: In step three, the stabilizer can be one of lotus root powder, pectin, or soybean polysaccharide. When adding the stabilizer, white sugar and glucose can be added in a 2:1 ratio.

7. The method for preparing fermented soybean milk with high retention rate of soybean germ protein according to claim 1, characterized in that: In step three, the inoculation amount of the compound strain is 3-4%, and after fermentation for 4-6 hours, its pH value is measured to be 4.5±0.1.