CN109517767B

CN109517767B - Lactobacillus plantarum strain, soymilk produced based on fermentation of strain and production method of soymilk

Info

Publication number: CN109517767B
Application number: CN201910054292.XA
Authority: CN
Inventors: 高秀芝; 易欣欣; 康建依; 陈孟; 刘一倩; 高逸; 刘慧�; 谢远红
Original assignee: Beijing University of Agriculture
Current assignee: Beijing University of Agriculture
Priority date: 2019-01-21
Filing date: 2019-01-21
Publication date: 2020-07-10
Anticipated expiration: 2039-01-21
Also published as: CN109517767A

Abstract

The invention provides a lactobacillus plantarum strain, soymilk produced based on the strain fermentation and a production method thereof, belonging to the technical field of soymilk production, the lactobacillus plantarum strain V02 and L actinobacillus plantarum with the preservation number of CGMCC No.16727 are used for soymilk fermentation, the fermentation period of the lactobacillus plantarum strain V02 is short, the soymilk obtained by fermentation has good coagulation property and higher sensory evaluation score.

Description

Lactobacillus plantarum strain, soymilk produced based on fermentation of strain and production method of soymilk

Technical Field

The invention belongs to the technical field of soymilk production, and particularly relates to a lactobacillus plantarum strain, soymilk produced based on the strain fermentation and a production method thereof.

Background

The soymilk has high nutritive value, contains functional components such as phospholipid, isoflavone and the like compared with milk, does not contain lactose and cholesterol, is particularly suitable for infants allergic to the milk and adults lack of lactase in vivo to drink, and is a milk substitute with development potential. The fermented soybean milk is prepared by fermenting soybean milk with or without fermentation promoter (milk or saccharide available for lactobacillus) with probiotic bacteria to obtain fermented soybean product similar to yogurt. The soybean milk has no loss of nutrient components, and the amino acid content is increased after the probiotic action, so that the soybean milk can have sour flavor in taste; the protease produced by the probiotics can destroy anti-nutritional factors in the soybeans, and the proteins in the soybeans are converted into small molecular short peptides through hydrolysis, so that the digestion and absorption of a human body are facilitated.

Probiotics (Probiotics) is a kind of active microorganisms beneficial to a host, and is a general term for active beneficial microorganisms which are planted in the intestinal tract and the reproductive system of a human body and can produce exact health effects so as to improve the microbial ecological balance of the host and play beneficial roles. The probiotics have good effects of reducing serum cholesterol, promoting the health of an intestinal tract digestive system, improving the immunity of a human body and the like. Dairy products, particularly fermented dairy products represented by yoghurt, are one of the best carriers for probiotics.

In the prior art, more probiotics are used for fermenting and producing the soymilk, but the problems of long fermentation period, poor sour-sweet degree, uneven texture, poor viscosity and fluidity and light yoghourt fragrance of the soymilk fermented by probiotics often exist, so that the taste is poor.

Disclosure of Invention

In view of the above, the invention aims to provide a lactobacillus plantarum strain, soymilk produced by fermentation based on the strain and a production method thereof, wherein the lactobacillus plantarum strain has the characteristics of short fermentation period, good fermentation coagulability of the fermented soymilk, and high sour-sweet degree and sensory evaluation.

The invention provides a lactobacillus plantarum strain V02, L actinobacillus plantarum for soybean milk fermentation, and the preservation number is CGMCC No. 16727.

The invention provides probiotic fermented soymilk which is prepared by fermenting the following raw materials by mass, 6-8% of fermentation liquor of lactobacillus plantarum strain V02, 15-20% of wet soybeans or soybean flour, 2-6% of additives and 65-80% of water, wherein the viable count of the lactobacillus plantarum strain V02 fermentation liquor is 4.0-7.0 × 10⁸CFU/g；

The preparation method of the fermentation liquor of the lactobacillus plantarum strain V02 comprises the following steps: inoculating the lactobacillus plantarum strain V02 into pure soymilk according to the inoculation amount of 2-5%, and fermenting at 37 ℃ until coagulation but no whey precipitation, thereby obtaining the fermentation liquid of the lactobacillus plantarum strain V02.

Preferably, the fermentation product is obtained by fermenting raw materials with the following mass concentrations: 7% of fermentation liquor of the lactobacillus plantarum V02, 18% of wet soybeans and 70% of water; the additive is a sweetener; the mass concentration of the sweetener is 5%.

Preferably, the fermentation product is obtained by fermenting raw materials with the following mass concentrations: 7% of fermentation liquor of the lactobacillus plantarum strain V02, 16% of bean flour and 74.5% of water; the additive is a sweetener; the mass concentration of the sweetener is 2.5%.

Preferably, the fermentation product is obtained by fermenting raw materials with the following mass concentrations: 8% of plant lactobacillus strain V02 fermentation liquor, 18% of wet soybeans and 70% of purified water; the additive is xylitol; the mass concentration of the xylitol is 4 percent.

Preferably, the wet soybeans are prepared by soaking dried soybeans and water for 8 hours according to the mass ratio of 1:5 and then peeling the soybeans.

The invention provides a preparation method of probiotic fermented soymilk, which is characterized by comprising the following steps:

1) mixing soybean milk obtained by grinding soybean powder or wet soybean with water, boiling, removing residue from the boiling liquid, and boiling again to obtain sterilized soybean milk;

2) and mixing the sterilized soymilk with a sweetening agent, boiling for the third time, cooling to below 40 ℃, inoculating fermentation liquor of lactobacillus plantarum strain V02 into the obtained mixed liquor, and fermenting at 37 ℃ until solidification is realized but no whey is separated out, thereby obtaining the probiotic fermented soymilk.

Preferably, when the raw material is soybean flour, the fermentation temperature is 37 ℃, and the fermentation time is 6-8 h.

Preferably, when the raw material is wet soybeans and the additive is a sweetening agent, the fermentation temperature is 37 ℃, and the fermentation time is 5-7 h.

Preferably, when the raw material is wet soybean and the additive is xylitol, the fermentation temperature is 37 ℃, and the fermentation time is 6-8 h.

The lactobacillus plantarum V02 and L actinobacillus plantarum for soymilk fermentation have the preservation number of CGMCC No. 16727. compared with other 5 lactobacillus plantarum strains derived from fermented vegetables, the lactobacillus plantarum V02 provided by the invention has shorter fermentation time of V02, and better performances in aspects of the coagulation degree and sensory evaluation (including appearance, color, flavor, taste, texture and the like) of fermented soymilk, and experiments prove that the lactobacillus plantarum V02 provided by the invention has the fermentation period of only 5-8 h, and the fermented product has good coagulation property, and through the sensory evaluation, the fermented soymilk has complete appearance, uniform texture, no whey precipitation, proper viscosity and fluidity, uniform and consistent color, milky white color, strong yogurt aroma, no unpleasant odor, proper sour and sweet taste, no rough lubrication, no obvious pores, uniform texture and higher sensory evaluation score.

Furthermore, the fermentation period of the lactobacillus plantarum strain V02 is short, and the fermented soybean milk not only has good coagulation property, but also has higher sensory evaluation score. Meanwhile, the sour soybean milk prepared from wet soybeans is suitable for people who like the taste of bean products, is suitable for people who do not like the beany flavor by taking the bean flour as a raw material and carrying out deodorization and homogenization treatment, and is also a sugar-free soybean milk suitable for people with milk allergy and diabetes. The main nutritional ingredients of the three kinds of soybean milk are vegetable protein, soybean phospholipid, calcium, phosphorus, iron, zinc and other mineral substances, and the soybean milk has the effects of improving nerve function, loosening bowel to relieve constipation, preventing and treating diabetes, increasing brain function, building body and the like.

Biological preservation information

Lactobacillus plantarum (L actinobacillus plantarum) is preserved in the common microorganism center of China Committee for culture Collection of microorganisms, the preservation time is 11 months and 12 days in 2018, the address is No. 3 of Xilu No.1 of Beijing university and Chaoyang district, the microorganism research institute of China academy of sciences, the biological preservation number is CGMCC No.16727, and the strain number is V02.

Detailed Description

The invention provides a lactobacillus plantarum strain V02, L actinobacillus plantarum with the preservation number of CGMCC No.16727 for soybean milk fermentation on MRS agar culture mediumThe size of a colony of bacillus (L actinobacillus plantarum) V02 strain is 2-3 mm, the colony has high viscosity, smooth surface, regular edge, circular bulge and milk white color, the individual shape is short rod-shaped, short chain-shaped and G⁺The fermented dairy product of lactobacillus plantarum (L actinobacillus plantarum) V02 strain derived from edible fermented vegetables can improve the immunity of organisms, adjust the structure of intestinal flora, increase the quantity of beneficial bacteria, reduce the quantity of harmful bacteria, prevent diarrhea and prevent gastric ulcer.

The invention provides probiotic fermented soymilk which is prepared by fermenting the following raw materials in mass concentration, wherein the raw materials comprise 6-8% of fermentation liquor of lactobacillus plantarum strain V02, 15-20% of wet soybeans or soybean flour, 2-6% of additives and 65-80% of water, and the viable count of the fermentation liquor of lactobacillus plantarum strain V02 is 4.0-7.0 × 10⁸CFU/g。

In the present invention, when the raw material is wet soybean, the fermented soybean milk is preferably obtained by fermenting raw materials including the following mass concentrations: 6-8% of fermentation liquor of lactobacillus plantarum strain V02, 15-20% of wet soybeans, 4-6% of additives and 66-80% of water; more preferably from fermentation of a feedstock comprising the following mass concentrations: 7% of fermentation liquor of the lactobacillus plantarum V02, 18% of wet soybeans, 5% of additive and 70% of water. The additive comprises sweetener or xylitol. When the additive is a sweetening agent, the sour soybean milk is prepared, and is suitable for people who like the taste of the soybean product. When the raw material is wet soybean and the additive is xylitol, the sugar-free soybean milk is prepared and is suitable for milk allergy people or diabetes patients. The wet soybeans are prepared by soaking dried soybeans and water for 8 hours according to the mass ratio of 1:5 and then peeling the soybeans. The water content of the wet soybeans is preferably 16-17%.

In the present invention, when the raw material is soybean flour, it is preferably fermented from the following raw materials by mass: 6-8% of fermentation liquor of lactobacillus plantarum strain V02, 15-17% of bean flour, 2-3% of sweetener and 70-83% of water; more preferably from fermentation of raw materials comprising the following mass concentrations: 7% of fermentation liquor of the lactobacillus plantarum strain V02, 16% of bean flour, 2.5% of sweetener and 74.5% of water. The soybean flour is subjected to flash evaporation deodorization tank deodorization and high-pressure homogenizer homogenization treatment.

In the invention, the sour soybean milk prepared from wet soybeans is suitable for people who like the taste of bean products, and the sour soybean milk prepared from the bean flour is suitable for people who do not like the beany flavor by deodorization and homogenization treatment (completely removing soybean hulls and germs). The main nutritional ingredients of the two formulas are vegetable protein, soybean phospholipid, calcium, phosphorus, iron, zinc and other mineral substances, and meanwhile, soybeans contain rich soybean isoflavone, and a large number of in vivo, in vitro and clinical tests prove that the efficacy of the soybean isoflavone is closely related to factors such as soybean matrix, diet and the like contained in food; meanwhile, the bioactive peptide generated after microbial fermentation also has certain influence on cardiovascular diseases, cancers, hypertension, osteoporosis and other diseases, so the fermented soybean milk provided by the invention has the effects of improving nerve functions, relaxing bowel, preventing and treating diabetes, increasing brain functions, building body and the like.

In the present invention, the raw material of the probiotic fermented soybean milk includes additives. The additive comprises sweetener or xylitol. The sweetener comprises one or more of white granulated sugar, sucrose, glucose and maltose syrup. The source of the sweetener is not particularly limited in the present invention, and any source of sweetener known in the art may be used.

In the present invention, the method for preparing the fermentation broth of lactobacillus plantarum strain V02 preferably comprises the following steps: inoculating lactobacillus plantarum strain V02 with an inoculum size of 2-5% into pure soybean milk, and fermenting at 37 ℃ until coagulation but no whey precipitation to obtain fermentation liquor of lactobacillus plantarum strain V02. The fermentation time is preferably 8-12 h, more preferably 9-11 h, and most preferably 10 h. The pure soymilk is prepared from 10-15% of soybean flour by mass concentration, 2-6% of additive by mass concentration and 79-88% of purified water by mass concentration, and is sterilized for 10min at 115 ℃ after being mixed for later use.The number of viable bacteria of the lactobacillus plantarum strain V02 fermentation liquor is preferably 4.0-7.0 × 10⁸CFU/g, more preferably 6.0 × 10⁸CFU/g. The additive is sweetener or xylitol. The sweetener comprises one or more of white granulated sugar, sucrose, glucose and maltose syrup. When sweetener is added to prepare pure soybean milk, the fermented soybean milk is suitable for people with diabetes. When xylitol is added to make pure soymilk, the fermented probiotic fermented soymilk is suitable for people with diabetes to drink.

In the present invention, the raw material of the probiotic fermented soymilk comprises water. The water is preferably purified water. The source of the purified water is not particularly limited in the present invention, and purified water known in the art may be used.

The invention provides a preparation method of probiotic fermented soymilk, which comprises the following steps:

In the invention, when the raw material is soybean flour, the fermentation temperature is preferably 37 ℃, and the fermentation time is preferably 6-8 h. When the raw materials are wet soybeans and the additive is a sweetening agent, the fermentation temperature is preferably 37 ℃, and the fermentation time is preferably 5-7 h. When the raw material is wet soybeans and the additive is xylitol, the fermentation temperature is preferably 37 ℃, and the fermentation time is preferably 6-8 h. In order to ensure that the coagulability and the sensory evaluation effect of the fermented sour soybean milk are better, when the raw materials are different, different fermentation temperatures and fermentation times are selected, and the fermented sour soybean milk is anaerobically cultured.

In the present invention, the boiling temperature is preferably 100 ℃. The inoculation amount of the fermentation liquor of the lactobacillus plantarum strain V02 is preferably 6-8%, and more preferably 7%.

The lactobacillus plantarum strain, soymilk produced by fermentation based on the strain, and a method for producing the same according to the present invention will be described in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.

Example 1

Screening method of lactobacillus plantarum strain

(1) 6 strains of Lactobacillus plantarum (strains V02, V16, V21, V41, V53 and V66, respectively) derived from fermented vegetables were used in the soybean milk fermentation experiment, respectively, as follows:

inoculating lactobacillus plantarum strain V02 into pure soybean milk (comprising 10-15% of soybean flour, 2-6% of additive (xylitol or white granulated sugar) and 79-88% of purified water according to the inoculation amount of 2-5%, mixing, and sterilizing at 115 ℃ for 10 min) to ferment at 37 ℃ until solidification without whey precipitation, thereby obtaining lactobacillus plantarum strain V02 fermentation liquid. Inoculating fermentation broth of Lactobacillus plantarum strain V02 into sterilized bean powder, and coagulating at 37 deg.C to obtain sour soybean milk.

(2) The fermented soybean milk prepared above was subjected to measurement of degree of coagulation, and statistical evaluation of fermentation time and sensory evaluation (see Table 1 for details).

The sensory evaluation method was as follows: the evaluation group is composed of professional evaluators (namely, the evaluation group is composed of persons trained in professional sensory evaluation), and 10 persons are in total, the appearance, color, flavor, taste and texture of the sample are respectively described in detail by using a descriptive detection method, and the result of the sensory evaluation is used as the evaluation standard of the single-factor multi-level test of the main ingredients of the probiotic fermented soymilk. Sensory evaluation standards and evaluation indexes of the probiotic fermented soymilk are shown in table 1.

TABLE 1 organoleptic evaluation criteria for probiotic fermented soymilk

Table 26 detection results of strains

Results are shown in Table 2. According to the results in Table 1, three strains V16, V21 and V41 are screened out, which have too long fermentation time and bad solidification state; screening out strains V53 and V66 with poor sensory evaluation; according to the coagulation degree and sensory evaluation results of the fermented soymilk, the fermentation effect of the lactobacillus plantarum V02 is better, the fermentation time is shorter and can be 5 hours, and finally the lactobacillus plantarum V02 is screened out for subsequent fermentation.

Example 2

Activation, enlarged culture and fermentation of lactobacillus plantarum V02 strain

(1) After lactobacillus plantarum V02 preserved in glycerol at the temperature of minus 80 ℃ is transferred and activated, the lactobacillus plantarum is subjected to amplification culture by a sterilized MRS culture medium and fermentation by a sterilized 100ml pure soymilk conical flask to obtain the viable count (4.0-7.0) × 10⁸CFU/g, pH value 4.0-4.5.

(2) Detection of viable bacteria quantity and pH value of lactobacillus plantarum V02

Weighing 25g of fermented milk, putting into sterilized physiological saline containing 225m L, treating for 1min at 8000-10000 r/min by using a slapping homogenizer, and fully oscillating to obtain 10^-1Diluting with 9m L sterilized normal saline 10 times to 10 times^-8(ii) a Get 10^-6～10^-8Placing the diluted solutions 1m L in a sterile plate, pouring a sterilized MRS culture medium which is melted and cooled to 44 ℃ and about 15m L, quickly and gently rotating the plate to fully mix the culture medium and bacterial liquid, repeating the dilution for 3 times, simultaneously injecting the sterilized MRS culture medium into the sterile plate added with 1m L sterile physiological saline as a blank control, turning over the plate after the culture medium is solidified, culturing in a temperature box at (36 +/-1) DEG C for (48 +/-2) h, counting after bacterial colonies grow out, wherein the counting result of the bacterial colonies of the plate shows that the number of the viable bacteria of the lactobacillus plantarum V02 in each 1ml is (4.0-7.0) × 10⁸CFU。

Preparing 50ml of fermented soybean milk, uniformly mixing the fermented soybean milk, measuring the fermented soybean milk by using a pH meter for three times, and taking the average value of the fermented soybean milk, wherein the pH value result shows that the pH value is 4.0-4.5.

(3) Process for preparing soybean milk

1) Weighing dry soybeans, wherein the purified water comprises 40% by weight of the dry soybeans and 60% by weight of the purified water, soaking the dry soybeans and the purified water at room temperature for about 10 hours, peeling the wet soybeans, and cleaning, wherein the wet soybeans and the purified water are 17% by weight: mixing at a ratio of 80%, grinding, boiling, and filtering for multiple times (the aperture of the filter is 1mm, and the filtering times are 3-5 times) to separate the slurry and the residue. Removing residue, and boiling again.

2) Mixing bean flour and purified water according to the weight ratio of 1: 4, and boiling to obtain the soybean milk.

(4) Process for preparing probiotics fermented soymilk

1) The preparation process of the single-strain fermented pure soymilk comprises the following steps: firstly, 6 percent of white granulated sugar is added into the boiled soymilk, the mixture is heated, boiled and mixed evenly, cooled to 40 ℃, 8 percent of lactobacillus plantarum V02 fermented milk is added into the soymilk and mixed evenly, the mixture is subpackaged into fermentation containers, the culture temperature is 37 ℃, and the culture time is according to the volume of the fermented soymilk until no whey is precipitated after solidification.

2) The preparation process of the single-strain fermented soybean milk comprises the following steps: firstly, adding 2 percent of white granulated sugar into the boiled soymilk, heating, boiling, uniformly mixing, cooling to 40 ℃, adding 8 percent of lactobacillus plantarum V02 fermented milk into the soymilk, uniformly mixing, subpackaging in a fermentation container, culturing at 37 ℃, and culturing for a time according to the volume of the fermented soymilk until no whey is precipitated after solidification.

3) The preparation process of the sugar-free pure soymilk fermented by single strain comprises the following steps: adding xylitol 4% into the boiled soybean milk, heating, boiling, mixing, cooling to 40 deg.C, adding lactobacillus plantarum V02 fermented milk 8% into the soybean milk, mixing, subpackaging in a fermentation container, culturing at 37 deg.C for a period of time according to the fermented soybean milk volume until no whey is precipitated after solidification.

4) Sensory evaluation of probiotic fermented soymilk was performed according to the sensory evaluation method described in example 1, and the evaluation results were recorded.

The prepared probiotic fermented soymilk product has the advantages of complete shape, uniform texture, no whey precipitation, proper viscosity and fluidity, uniform and consistent color, milky white color, strong fragrance of the yogurt, no bad smell, fine, smooth, proper sweet and sour taste, lubrication, no roughness, no obvious pores, uniform texture and highest sensory evaluation score.

Example 3

Detection of viable count of lactobacillus plantarum V02 in probiotic fermented soymilk

Weighing 25g of probiotic fermented soybean milk, putting into sterilized physiological saline containing 225m L, treating for 10s at 8000-10000 r/min by using a slapping homogenizer, and fully oscillating to obtain 10^-1The diluted solution is diluted by 9m L sterilized normal saline with 10 times of increasing dilution to 10^-11Take 10^-6～10^-9Placing the diluted solutions with the volume of 1m L in a sterile plate, pouring modified MRS culture medium with the volume of about 15m L which is dissolved and cooled to 46 ℃, quickly and lightly rotating the plate to fully mix the culture medium and bacterial liquid, repeating the dilution for 3 times, simultaneously injecting the modified MRS culture medium into the sterile plate added with 1m L sterile normal saline as a blank control, turning over the plate after the culture medium is solidified, culturing in a temperature box with the temperature of 36 +/-1 ℃ for 48 +/-2 h, and counting after bacterial colonies grow out, wherein the bacterial colonies on the plate are counted and the pH value result shows that the number of the viable bacteria of the fermented pure soymilk probiotics is (4.0-7.0) × 10⁸CFU/g, pH 4.0-4.5.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. Lactobacillus plantarum (L actinobacillus plantarum) strain V02 for soybean milk fermentation has a preservation number of CGMCC No. 16727.

2. The probiotic fermented soymilk is characterized by being prepared by fermenting the following raw materials in mass concentration: 6-8% of fermentation liquor of lactobacillus plantarum strain V02, 15-20% of wet soybeans or soybean flour, 2-6% of additives and 65-74.5% of water;

the viable count of the lactobacillus plantarum strain V02 fermentation liquor is 4.0-7.0 × 10⁸CFU/g；

The preparation method of the fermentation liquor of the lactobacillus plantarum strain V02 comprises the following steps: inoculating 2-5% of lactobacillus plantarum strain V02 of claim 1 into pure soybean milk, and fermenting at 37 deg.C until coagulation but no whey precipitation to obtain fermentation broth of lactobacillus plantarum strain V02.

3. The probiotic fermented soymilk according to claim 2, characterized in that it is fermented from raw materials comprising, in mass concentrations: 7% fermentation broth of lactobacillus plantarum strain V02, according to claim 1, 18% wet soybeans and 70% water; the additive is a sweetener; the mass concentration of the sweetener is 5%.

4. The probiotic fermented soymilk according to claim 2, characterized in that it is fermented from raw materials comprising, in mass concentrations: 7% fermentation broth, 16% soy flour and 74.5% water of lactobacillus plantarum strain V02, described in claim 1; the additive is a sweetener; the mass concentration of the sweetener is 2.5%.

5. The probiotic fermented soymilk according to claim 2, characterized in that it is fermented from raw materials comprising, in mass concentrations: 8% of lactobacillus plantarum V02 fermentation liquor, 18% of wet soybeans and 70% of purified water; the additive is xylitol; the mass concentration of the xylitol is 4 percent.

6. The probiotic fermented soymilk according to any one of claims 2, 3 and 5, characterized in that the wet soybeans are prepared by soaking sun-dried soybeans and water in a mass ratio of 1:5 for 8h and then peeling the soybeans.

7. A method of producing probiotic fermented soymilk according to any one of claims 2 to 6, characterized in that it comprises the following steps:

2) and mixing the sterilized soymilk with an additive, boiling for the third time, cooling to below 40 ℃, inoculating fermentation liquor of lactobacillus plantarum strain V02 into the obtained mixed liquor, and fermenting at 37 ℃ until solidification is realized without whey separation to obtain the probiotic fermented soymilk.

8. The preparation method according to claim 7, wherein when the raw material is soybean flour, the fermentation temperature is 37 ℃ and the fermentation time is 6-8 h.

9. The preparation method according to claim 7, wherein when the raw material is wet soybeans and the additive is a sweetener, the fermentation temperature is 37 ℃ and the fermentation time is 5-7 h.

10. The preparation method according to claim 7, wherein when the raw material is wet soybeans and the additive is xylitol, the fermentation temperature is 37 ℃ and the fermentation time is 6-8 h.