阅读说明：本技术 一种采用豆粕为原料制备酸豆乳发酵剂的工艺 (Process for preparing acid soybean milk leaven by taking soybean meal as raw material ) 是由 陈慎 杨成龙 黄颖颖 陆东和 于 2020-06-12 设计创作，主要内容包括：本发明公开了一种采用豆粕为原料制备酸豆乳发酵剂的工艺,包括以下步骤：1)原料处理、2)酶解、3)离心、4)高压均质、5)灭菌、6)冷却、7)接种、8)保温发酵、9)破乳、10)离心、11)冻干、12)分装。本发明通过对豆粕进行利用制备直投式发酵剂产品,一方面可对大豆副产物进行充分利用,提高植物蛋白的利用率,另一方面促进发酵剂产业发展,降低发酵乳饮品的成本。本发明艺通过添加破乳剂,提升水乳分离效果,降低离心强度,减少离心对活菌的破坏；本发明缩短了冻干时间,降低能耗,最大限度的保留活菌数,制得的酸豆乳发酵剂,包含嗜热链球菌及保加利亚乳杆菌的活菌数保留率可达到60%-70%。(The invention discloses a process for preparing an acid soybean milk leaven by taking soybean meal as a raw material, which comprises the following steps: 1) raw material treatment, 2) enzymolysis, 3) centrifugation, 4) high-pressure homogenization, 5) sterilization, 6) cooling, 7) inoculation, 8) heat preservation fermentation, 9) demulsification, 10) centrifugation, 11) freeze-drying and 12) subpackaging. According to the invention, the soybean meal is utilized to prepare the direct vat set starter product, so that on one hand, soybean byproducts can be fully utilized, the utilization rate of vegetable protein is improved, on the other hand, the development of starter industry is promoted, and the cost of fermented milk drinks is reduced. According to the invention, the demulsifier is added, so that the water-milk separation effect is improved, the centrifugal strength is reduced, and the damage of centrifugation to live bacteria is reduced; the invention shortens the freeze-drying time, reduces the energy consumption, and furthest reserves the viable count, and the retention rate of the viable count of the prepared sour soybean milk leaven containing the streptococcus thermophilus and the lactobacillus bulgaricus can reach 60-70%.)

1. A process for preparing an acid soybean milk leaven by taking soybean meal as a raw material is characterized by comprising the following steps: which comprises the following steps:

1) raw material treatment: pouring the soybean meal into a grinder for grinding;

2) enzymolysis: mixing the crushed soybean meal with water, adjusting the pH value to 7.8-8.2, adding alkaline protease, and carrying out enzymolysis at 54-56 ℃ to obtain soybean meal enzymolysis liquid;

3) centrifuging: centrifuging the bean pulp enzymolysis liquid, carrying out residue-liquid separation, and collecting bean pulp soymilk;

4) high-pressure homogenization: homogenizing the soybean meal soymilk under the conditions of pressure of 25-28 mPa and temperature of 65-75 ℃ for 10-15 min;

5) and (3) sterilization: sterilizing the feed liquid;

6) and (3) cooling: cooling the sterilized feed liquid to 35-45 ℃;

7) inoculation: inoculating passage type microbial inoculum activated in advance, wherein the microbial inoculum contains viable bacteria of Streptococcus thermophilus and Lactobacillus bulgaricus, and the viable bacteria number is not less than 10⁸CFU/g, the usage amount of the microbial inoculum is 0.05 to 0.1 percent of the total weight of the feed liquid

8) And (3) heat preservation fermentation: uniformly stirring the inoculated feed liquid, culturing for 3-5 h at 37-42 ℃ in a constant temperature and humidity box, and stopping fermentation when the inoculated feed liquid reaches a solidification state;

9) demulsifying: adding a demulsifier accounting for 0.05-0.1 percent of the total weight of the feed liquid into the feed liquid, and reacting for 30-60min at 40-50 ℃;

10) centrifuging: centrifuging the feed liquid, collecting bacterial sludge, adding freeze-drying protective agent, mixing, and packaging;

11) freeze-drying: placing the obtained bacterial mud into a freeze dryer, and spreading to a thickness of 20-40 mm; after the plate is paved, pre-freezing is carried out, the pre-freezing temperature is from minus 40 ℃ to minus 30 ℃, the pre-freezing time is 2h to 4h, and then freeze-drying is carried out in four stages;

12) subpackaging: and (3) crushing the powder cake obtained after freeze-drying, and subpackaging to obtain the sour soybean milk starter.

2. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 2), the dosage ratio of the soybean meal to the water is 1g:8 mL-1 g:10 mL.

3. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 2), the enzyme dosage is 1200 u/g-1400 u/g, and the enzymolysis time is 1.5h-2 h.

4. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 3), the rotating speed of the centrifugation is 4000-5000 r/min, and the centrifugation time is 10-15 min.

5. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 5), the sterilization mode is pasteurization or high-temperature sterilization or ultrahigh-temperature instant sterilization.

6. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 9), the demulsifier is sodium chloride, sodium sulfate, calcium carbonate or potassium carbonate.

7. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 10), the components and the mass percentage of the freeze-drying protective agent are as follows: 3-6% of glycerol, 3-6% of trehalose, 0.5-1% of cysteine hydrochloride and the balance of water, wherein the total amount of all the components is 100%.

8. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 10), the volume ratio of the freeze-drying protective agent to the bacterial sludge is 4: 1.

9. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in the step 10), the rotating speed of the centrifugation is 3000rpm-5000rpm, and the centrifugation time is 5min-15 min.

10. The process for preparing the acid soybean milk starter by using the soybean meal as the raw material according to claim 1, which is characterized in that: in step 11), after pre-freezing, freeze-drying is carried out according to the following four stages:

a first freeze-drying stage, wherein the temperature is controlled to be between 50 ℃ below zero and 40 ℃ below zero, the freeze-drying time is 2 to 4 hours, and the vacuum degree is 30 to 40 Pa;

freeze-drying for 2-4 h at-30 deg.C to-20 deg.C under vacuum degree of 20Pa to 30 Pa;

a third freeze-drying stage, wherein the temperature is controlled to be between 10 ℃ below zero and 5 ℃ below zero, the freeze-drying time is 15 to 20 hours, and the vacuum degree is 15 to 20 Pa;

and a fourth freeze-drying stage, wherein the temperature is controlled to be 0-10 ℃, the freeze-drying time is 2-5 h, and the vacuum degree is 10-15 Pa.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to a process for preparing an acid soybean milk leavening agent by taking soybean meal as a raw material.

Background

The rich vegetable protein in the soybean can solve the problem of insufficient intake of high-quality protein in the dietary structure, and simultaneously, the soybean milk does not contain lactose, so the soybean milk is very suitable for lactose intolerance people to drink. Second floor 200

The soybean meal is a byproduct of oil extraction of soybeans by a low-temperature prepressing extraction method, the protein content is high, the essential amino acid composition is reasonable, and the water-soluble protein accounts for more than 80%. Therefore, the soybean meal is one of the resources with quite rich vegetable protein content which can be developed and utilized as a byproduct of oil and fat processing. Currently, soybean meal is mainly used for producing animal feed and extracting soybean protein, and only a small part of soybean meal is used as a raw material for producing fermented foods, so that a great deal of waste of protein resources is caused.

Meanwhile, the current domestic leavening agent mainly depends on import, so that the price of the fermented milk product is high, and the development of the industry is restricted. At present, the technology for preparing the soymilk by using soybean raw materials such as soybeans, black beans and the like is mature, the application of soybean meal is less, and meanwhile, relevant reports for preparing fermented beverages by using the soybean meal as the raw material are not seen, so that the development of the soybean meal as the fermented sour soymilk has feasibility.

Disclosure of Invention

The invention aims to provide a process for preparing an acid soybean milk leaven by taking soybean meal as a raw material.

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

a process for preparing an acid soybean milk leaven by taking soybean meal as a raw material comprises the following steps:

1) raw material treatment: pouring the soybean meal into a grinder for grinding;

2) enzymolysis: mixing the crushed soybean meal with water, adjusting the pH value to 7.8-8.2, adding alkaline protease, and carrying out enzymolysis at 54-56 ℃ to obtain soybean meal enzymolysis liquid;

3) centrifuging: centrifuging the bean pulp enzymolysis liquid, carrying out residue-liquid separation, and collecting bean pulp soymilk;

4) high-pressure homogenization: homogenizing the soybean meal soymilk for 10-15min under the conditions of the pressure of 25-28 mPa and the temperature of 65-75 ℃, and further refining the soybean meal soymilk particles to form uniform and stable feed liquid;

5) and (3) sterilization: sterilizing the feed liquid;

6) and (3) cooling: cooling the sterilized feed liquid to 35-45 ℃;

7) inoculation: inoculating passage type microbial inoculum activated in advance, wherein the microbial inoculum contains viable bacteria of Streptococcus thermophilus and Lactobacillus bulgaricus, and the viable bacteria number is not less than 10⁸CFU/g, the usage amount of the microbial inoculum is 0.05-0.1 percent of the total weight of the feed liquid, and the process keeps sterility to avoid the pollution of mixed bacteria;

8) and (3) heat preservation fermentation: stirring the inoculated material liquid, culturing at 37-42 deg.C for 3-5 h in a constant temperature and humidity chamber, stopping fermentation when the material liquid reaches solidification state, and stopping fermentation until the viable count reaches 10¹⁰CFU/g；

9) Demulsifying: adding a demulsifier accounting for 0.05-0.1 percent of the total weight of the feed liquid into the feed liquid, and reacting for 30-60min at 40-50 ℃;

10) centrifuging: centrifuging with a horizontal centrifuge or a disc separator, collecting bacterial sludge after centrifuging the feed liquid, adding freeze-drying protectant, mixing, and packaging;

11) freeze-drying: placing the obtained bacterial mud into a freeze dryer, and spreading to a thickness of 20-40 mm; after the plate spreading is finished, pre-freezing is carried out, the pre-freezing temperature is from minus 40 ℃ to minus 30 ℃, the pre-freezing time is 2h to 4h, and then freeze-drying is carried out in four stages;

12) subpackaging: and (3) crushing the powder cake obtained after freeze-drying, crushing to the fineness of 40-80 meshes, and subpackaging to obtain the fermented soybean milk.

In the step 2), the dosage ratio of the soybean meal to the water is 1g:8 mL-1 g:10 mL.

In the step 2), the enzyme dosage is 1200 u/g-1400 u/g, and the enzymolysis time is 1.5h-2 h.

In the step 3), the rotating speed of the centrifugation is 4000-5000 r/min, and the centrifugation time is 10-15 min.

In the step 5), the sterilization mode is pasteurization or high-temperature sterilization or ultrahigh-temperature instant sterilization.

In the step 9), the demulsifier is sodium chloride, sodium sulfate, calcium carbonate or potassium carbonate.

In the step 10), the components and the mass percentage of the freeze-drying protective agent are as follows: 3-6% of glycerol, 3-6% of trehalose, 0.5-1% of cysteine hydrochloride and the balance of water, wherein the total amount of all the components is 100%.

In the step 10), the volume ratio of the freeze-drying protective agent to the bacterial sludge is 4: 1.

In the step 10), the rotating speed of the centrifugation is 3000rpm-5000rpm, and the centrifugation time is 5min-15 min.

In step 11), after pre-freezing, freeze-drying is carried out according to the following four stages:

a first freeze-drying stage, wherein the temperature is controlled to be between 50 ℃ below zero and 40 ℃ below zero, the freeze-drying time is 2 to 4 hours, and the vacuum degree is 30 to 40 Pa;

freeze-drying for 2-4 h at-30 deg.C to-20 deg.C under vacuum degree of 20Pa to 30 Pa;

a third freeze-drying stage, wherein the temperature is controlled to be between 10 ℃ below zero and 5 ℃ below zero, the freeze-drying time is 15 to 20 hours, and the vacuum degree is 15 to 20 Pa;

and a fourth freeze-drying stage, wherein the temperature is controlled to be 0-10 ℃, the freeze-drying time is 2-5 h, and the vacuum degree is 10-15 Pa.

According to the invention, the soybean meal is utilized to prepare the direct vat set starter product, so that on one hand, soybean byproducts can be fully utilized, the utilization rate of vegetable protein is improved, on the other hand, the development of starter industry is promoted, and the cost of fermented milk drinks is reduced. The invention has the following advantages:

1. through adding the demulsifier, promote the water-milk separation effect, reduce centrifugal strength, reduce the centrifugal destruction to the live bacteria.

2. The freeze-drying time is shortened, the energy consumption is reduced, and the viable count is kept to the maximum extent. The sour soybean milk starter obtained by the method has the viable count retention rate of 60-70% and contains streptococcus thermophilus and lactobacillus bulgaricus.

3. Experiments prove that compared with the microbial inoculum prepared by the conventional process, the sour soybean milk starter prepared by centrifugal freeze-drying on the basis of adding the demulsifier has obvious advantages, the viable count retention rate reaches 90.3 +/-0.1 percent, the freeze-drying time is shortened to 20-36h, and the water content of the microbial inoculum is reduced to 1.3 +/-0.2 percent.

Detailed Description

A process for preparing an acid soybean milk leaven by taking soybean meal as a raw material comprises the following steps:

1) raw material treatment: screening the bean pulp, removing impurities of the non-bean pulp under the conditions of no color change and no peculiar smell, and then pouring the bean pulp into a grinder for grinding;

2) enzymolysis: mixing the crushed soybean meal with water according to a feed-liquid ratio of 1g:8 mL-1 g:10mL, adjusting the pH value to 7.8-8.2, adding alkaline protease with the enzyme dosage of 1200 u/g-1400 u/g, and carrying out enzymolysis for 1.5h-2h at 54-56 ℃ to obtain soybean meal enzymolysis liquid;

3) centrifuging: centrifuging the bean pulp enzymatic hydrolysate for 10-15min under the condition of 4000-5000 r/min, carrying out residue-liquid separation, and collecting bean pulp soymilk;

4) high-pressure homogenization: homogenizing the soybean meal soymilk for 10-15min under the conditions of the pressure of 25-28 mPa and the temperature of 65-75 ℃, and further refining the soybean meal soymilk particles to form uniform and stable feed liquid;

5) and (3) sterilization: sterilizing the above feed liquid by pasteurization, high temperature sterilization or ultrahigh temperature instantaneous sterilization;

6) and (3) cooling: cooling the sterilized feed liquid to 35-45 ℃;

7) inoculation: inoculating passage type microbial inoculum activated in advance, wherein the microbial inoculum contains viable bacteria of Streptococcus thermophilus and Lactobacillus bulgaricus, and the viable bacteria number is not less than 10⁸CFU/g, the usage amount of the microbial inoculum is 0.05-0.1 percent of the total weight of the feed liquid, and the process keeps sterility to avoid the pollution of mixed bacteria;

8) and (3) heat preservation fermentation: stirring the inoculated material liquid, culturing at 37-42 deg.C for 3-5 h in a constant temperature and humidity chamber, stopping fermentation when the material liquid reaches solidification state, and stopping fermentation until the viable count reaches 10¹⁰CFU/g；

9) Demulsifying: adding a demulsifier accounting for 0.05-0.1 percent of the total weight of the feed liquid into the feed liquid, and reacting for 30-60min at 40-50 ℃;

the demulsifier is sodium chloride, sodium sulfate, calcium carbonate or potassium carbonate;

10) centrifuging: centrifuging with a horizontal centrifuge or a disc separator at 3000-5000 rpm for 5-15 min; centrifuging, collecting bacterial sludge, adding a freeze-drying protective agent, uniformly mixing the freeze-drying protective agent and the bacterial sludge according to the volume ratio of the freeze-drying protective agent to the bacterial sludge of 4: 1, and subpackaging;

the freeze-drying protective agent comprises the following components in percentage by mass: 3-6% of glycerol, 3-6% of trehalose, 0.5-1% of cysteine hydrochloride and the balance of water, wherein the total amount of all the components is 100%;

11) freeze-drying: placing the obtained bacterial mud into a freeze dryer, and spreading to a thickness of 20-40 mm; pre-freezing at the temperature of minus 40 ℃ to minus 30 ℃ for 2h to 4h after the laying of the plate is finished; lyophilization was then performed in four stages:

a first freeze-drying stage, wherein the temperature is controlled to be between 50 ℃ below zero and 40 ℃ below zero, the freeze-drying time is 2 to 4 hours, and the vacuum degree is 30 to 40 Pa;

freeze-drying for 2-4 h at-30 deg.C to-20 deg.C under vacuum degree of 20Pa to 30 Pa;

a third freeze-drying stage, wherein the temperature is controlled to be between 10 ℃ below zero and 5 ℃ below zero, the freeze-drying time is 15 to 20 hours, and the vacuum degree is 15 to 20 Pa;

a fourth freeze-drying stage, wherein the temperature is controlled to be 0-10 ℃, the freeze-drying time is 2-5 h, and the vacuum degree is 10-15 Pa;

12) subpackaging: and (3) crushing the powder cake obtained after freeze-drying, crushing to the fineness of 40-80 meshes, and subpackaging to obtain the fermented soybean milk.