阅读说明：本技术 一种风味酸奶及其制备方法 (Flavored yogurt and preparation method thereof ) 是由 邓凯 许洪宇 李原野 何项伟 张宝龙 关德全 吕青山 许加彬 于 2021-08-31 设计创作，主要内容包括：本发明涉及乳制品制备方法领域,具体公开了一种风味酸奶及其制备方法,所述风味酸奶由以下重量份数的组分制备而成：脱脂牛奶70-90份,坚果添加物1-2份,谷物添加物1-2份,变性淀粉2-4份,白砂糖6-8份,接种量为1-3％的发酵剂。本发明制备得到的风味酸奶营养价值高,流动性好,风味极佳。(The invention relates to the field of dairy product preparation methods, and particularly discloses a flavored yogurt and a preparation method thereof, wherein the flavored yogurt is prepared from the following components in parts by weight: 70-90 parts of skimmed milk, 1-2 parts of nut additives, 1-2 parts of grain additives, 2-4 parts of modified starch, 6-8 parts of white granulated sugar and 1-3% of an inoculation amount of a leavening agent. The flavored yogurt prepared by the invention has high nutritive value, good fluidity and excellent flavor.)

1. The flavored yoghourt is characterized by being prepared from the following components in parts by weight:

70-90 parts of skimmed milk, 1-2 parts of nut additives, 1-2 parts of grain additives, 2-4 parts of modified starch, 6-8 parts of white granulated sugar and 1-3% of an inoculation amount of a leavening agent;

the leaven is prepared by mixing lactobacillus rhamnosus ZL-136, lactobacillus plantarum 2P and bifidobacterium bifidum according to the mass ratio of 1-2:1: 1.

2. The flavored yogurt of claim 1, wherein the modified starch is any one of potato modified starch, corn modified starch, potato modified starch, tapioca modified starch, rice modified starch and wheat modified starch.

3. The flavored yogurt of claim 2, prepared from the following components in parts by weight:

80 parts of skimmed milk, 1 part of nut additive, 1 part of grain additive, 3 parts of modified starch, 7 parts of white granulated sugar and 1.5% of inoculum size.

4. A method of preparing a flavoured yoghurt as claimed in any one of claims 1 to 2, comprising the steps of:

s1, preparing the following raw materials in parts by weight: 70-90 parts of skimmed milk, 1-2 parts of nut additives, 1-2 parts of grain additives, 2-4 parts of modified starch, 6-8 parts of white granulated sugar and 1-3% of an inoculation amount of a leavening agent for later use;

s2, preparing materials: uniformly mixing the skim milk, the nut additive and the grain additive, heating, adding a mixture of modified starch and white granulated sugar prepared in advance while stirring, and stirring until the mixture is completely dissolved;

s3, preheating and homogenizing: preheating after complete dissolution, and then homogenizing;

s4, sterilization: sterilizing after homogenizing to obtain sterile nutritional milk;

s5, inoculating and fermenting: inoculating 1-3% of the starter in sterile nutritional milk, sealing and fermenting for 8-12h, and fermenting at 4 deg.C for 94-98h to obtain flavored yogurt.

5. The method for preparing flavored yogurt as claimed in claim 4, wherein in S1, the nut supplement is prepared by mixing crushed walnut and crushed pine nut at a mass ratio of 1: 1.

6. The method for preparing flavored yogurt according to claim 5, wherein in S1, the cereal supplement is prepared by mixing oat grains and white sesame seeds in a mass ratio of 1:1: 1.

7. The method for preparing flavored yogurt according to claim 6, wherein the heating temperature in S2 is 50-60 ℃.

8. The method for preparing flavored yogurt according to claim 7, wherein the preheating condition in S3 is 40-50 ℃ for 20-30 min.

9. The method of claim 8, wherein the S3 is homogenized at 18-20MPa and 65-75 ℃.

10. The method of claim 9, wherein the sterilization conditions in S4 are 95 ℃ and 300S.

Technical Field

The invention relates to the field of dairy product preparation methods, and particularly relates to flavored yogurt and a preparation method thereof.

Background

The yoghourt is a dairy product and is produced by fermenting animal milk with lactic acid bacteria, and the probiotics in the yoghourt has the effect of helping digestion and is popular with consumers. The yoghourt enables nutritional ingredients such as protein to be absorbed by human bodies more easily through fermentation, and therefore the yoghourt has the effects of helping digestion, relaxing bowels and moistening intestines.

The existing yoghourt product has relatively single taste, single strain for yoghourt fermentation, poor fluidity of most of the yoghourt, short preservation time of most of the existing yoghourt, about 7-10 days, and great inconvenience for the yoghourt sale and consumer consumption in the existing market.

Disclosure of Invention

In order to solve the technical problems, the invention provides the flavor yoghourt and the preparation method thereof, and the prepared flavor yoghourt has good fluidity, excellent flavor and long shelf life.

The invention aims to provide a flavored yoghourt and the flavored yoghourt is prepared from the following components in parts by weight:

70-90 parts of skimmed milk, 1-2 parts of nut additives, 1-2 parts of grain additives, 2-4 parts of modified starch, 6-8 parts of white granulated sugar and 1-3% of an inoculation amount of a leavening agent;

the skim milk is obtained by degreasing bovine colostrum;

the leaven is prepared by mixing lactobacillus rhamnosus ZL-136, lactobacillus plantarum 2P and bifidobacterium bifidum according to the mass ratio of 1-2:1: 1.

Further, the modified starch is any one of potato modified starch, corn modified starch, potato modified starch, tapioca modified starch, rice modified starch and wheat modified starch.

Further, the flavored yoghourt is prepared from the following components in parts by weight:

80 parts of skimmed milk, 1 part of nut additive, 1 part of grain additive, 3 parts of modified starch, 7 parts of white granulated sugar and 1.5% of inoculum size.

The second purpose of the invention is to provide a preparation method of the flavored yoghourt, which comprises the following steps:

s1, preparing the following raw materials in parts by weight: 70-90 parts of skimmed milk, 1-2 parts of nut additives, 1-2 parts of grain additives, 2-4 parts of modified starch, 6-8 parts of white granulated sugar and 1-3% of an inoculation amount of a leavening agent for later use;

s2, preparing materials: uniformly mixing the skim milk, the nut additive and the grain additive, heating, adding a mixture of modified starch and white granulated sugar prepared in advance while stirring, and stirring until the mixture is completely dissolved;

s3, preheating and homogenizing: preheating after complete dissolution, and then homogenizing;

s4, sterilization: sterilizing after homogenizing to obtain sterile nutritional milk;

s5, inoculating and fermenting: inoculating 1-3% of the starter in sterile nutritional milk, sealing and fermenting for 8-12h, and fermenting at 4 deg.C for 94-98h to obtain flavored yogurt.

Further, in S1, the nut additive is prepared by mixing crushed walnut and crushed pine nut according to the mass ratio of 1: 1.

Further, in S1, the cereal additive is prepared by mixing oat grains and white sesame seeds according to the mass ratio of 1:1: 1.

In S2, the heating temperature is 50-60 ℃.

Further, in S3, the preheating condition is 40-50 ℃ for 20-30 min.

Further, in S3, the homogenizing condition is 18-20Mpa, 65-75 ℃.

Further, in S4, the sterilization conditions were 95 ℃ for 300 seconds.

Compared with the prior art, the invention has the beneficial effects that:

1. the functions and the relativity of the raw materials used in the invention are as follows:

(1) the Russian strain is a traditional starter strain in the Russian Gauss region, the shelf life of the flavored yogurt prepared by fermenting and prolonging the fermentation time by using the strain is longer (27 days), and is about 4 times of the shelf life of most yogurt (7 days) in the current market;

(2) the bovine colostrum used by the invention contains a large amount of immune and growth factors, such as immunoglobulin, insulin-like growth factor, lactoferrin, lysozyme and the like, can improve the immune function of a human body, and is used for preparing the yoghourt, so that the nutritive value of the yoghourt is greatly improved;

(3) in the nut additive used by the invention, 86% of fat of the walnut is unsaturated fatty acid, the walnut is rich in copper, magnesium, potassium, vitamin B6, folic acid and vitamin B1, also contains fiber, phosphorus, nicotinic acid, iron, vitamin B2 and pantothenic acid, and the walnut is rich in rich omega-3 fatty acid, so that the probability of suffering from depression can be reduced; the pine nuts are rich in unsaturated fatty acids such as linoleic acid, linoleic acid and the like, can reduce blood fat and prevent cardiovascular diseases, and a large amount of mineral substances such as calcium, iron, phosphorus, potassium and the like contained in the pine nuts can provide rich nutritional ingredients for body tissues;

(4) in the grain additives used in the invention, the oat has high nutritive value, contains rich linoleic acid, has rich protein and amino acid contents which are far higher than those of rice, wheat and the like, also contains rich vitamins including vitamin B1, vitamin B2, more vitamin E, nicotinic acid, folic acid and the like, and can supplement some trace elements and vitamins which are easily lacked in daily life for human bodies;

the white sesame contains 25 to 50 percent of a large amount of fat and 8 to 20 percent of protein, and also contains 3 to 10 percent of carbohydrate, vitamin a, vitamin e, lecithin, calcium, iron, magnesium and other nutritional ingredients, has the function of regulating cholesterol, and also has the effects of beautifying and resisting aging.

2. The flavor yoghourt prepared by the invention has the advantages of uniform milk quality, excellent viscosity and shape, about 4 times of the shelf life of the conventional yoghourt, good fluidity and excellent flavor.

3. The Russian strains do not exist independently, and the Lactobacillus rhamnosus ZL-136 can promote the growth of Bifidobacterium bifidum and Lactobacillus plantarum 2P, regulate the balance of intestinal flora under the interaction of the strains and promote digestion.

4. The lactobacillus rhamnosus ZL-136 in the leavening agent can inhibit the growth of bacillus subtilis, staphylococcus aureus, beta hemolytic streptococcus, escherichia coli, salmonella typhi, shigella and shigella boydii, and has small difference in inhibition capacity on gram-positive bacteria and gram-negative bacteria; although lactobacillus plantarum 2P cannot inhibit gram-negative bacteria, the lactobacillus plantarum 2P has a certain inhibition effect on pathogenic bacteria such as staphylococcus aureus, bacillus subtilis, beta hemolytic streptococcus and the like; bifidobacterium bifidum can inhibit all the above strains, and has strong inhibitory activity against gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and beta hemolytic streptococcus); the three strains can enhance the gastrointestinal function and inhibit various common pathogenic bacteria after being fermented as a leaven, so that the health of food is ensured, and the strain is good news in the food field.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a preparation process for preparing flavored yogurt in example 1 of the present invention.

Detailed Description

The following detailed description of specific embodiments of the invention is provided, but it should be understood that the scope of the invention is not limited to the specific embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. The experimental methods described in the examples of the present invention are all conventional methods unless otherwise specified.

Example 1:

bacteriostatic property of leaven

1. The fermenting agent selects Russian strains including Lactobacillus rhamnosus ZL-136 (with the strain number of B-12110), Lactobacillus plantarum 2P (with the strain number of B-1615) and Bifidobacterium bifidum (with the strain number of AC-1890), and the Russian strains are purchased from Russian national industrial microorganism collection center.

2. Inhibition spectra experiment of Russian strains

(1) Preparing an indicator bacterium: staphylococcus aureus, escherichia coli, bacillus subtilis, salmonella typhi, shigella, shigella boydii and beta hemolytic streptococcus; the sources of the strains are as follows:

the staphylococcus aureus, the escherichia coli and the bacillus subtilis are original laboratory-preserved strains;

culturing staphylococcus aureus by using a nutrient broth agar culture medium, and culturing escherichia coli and bacillus subtilis by using an LB culture medium;

salmonella typhi is purchased from Ningbo Ming boat Biotechnology Co., Ltd, and the product number is BMZ133795, and is inoculated to ss agar culture medium;

shigella shigella is purchased from Shanghai-research Biotechnology Co., Ltd, and cultured in LB medium under the product number EY-1240J;

shigella boydii (strain number CMCC51522) is purchased from Nanjing shiso-called Biotechnology Limited and cultured in nutrient broth agar medium;

the beta hemolytic streptococcus is purchased from Shanghai Hainan industry Co., Ltd, has a product number of FS-J0300, and is cultured by a nutrient broth agar culture medium;

preparing corresponding liquid culture medium and solid culture medium according to the culture medium suitable for different strains for later use.

(2) Respectively culturing the indicator bacteria with respective corresponding liquid culture media, and then coating the indicator bacteria on a solid plate, wherein three plates are prepared for each bacteria; the method specifically comprises the following steps:

respectively culturing the above strains until the bacterial liquid concentration reaches OD₆₀₀Diluting with sterile water five times to obtain bacterial suspension after the concentration is 0.7, sucking 600 μ L of bacterial suspension with a pipette, injecting into a solid plate prepared in advance, and uniformly coating with a sterilized coating rod;

(3) preparing Russian fungus suspension

Respectively using Russian strains (Lactobacillus rhamnosus ZL-136 strain and Lactobacillus plantarum 2P) used by the inventionAnd Bifidobacterium bifidum) in MRS liquid medium, and culturing to obtain bacterial liquid OD₆₀₀Equal to 0.7, for standby;

(4) punching holes on the indicator bacterium plates coated with the indicator bacterium plates by using a sterilized puncher, respectively punching holes in triangular positions on each plate, punching three holes on one plate, sucking the Lactobacillus rhamnosus ZL-136 bacterial suspension prepared in the step (3), adding the Lactobacillus plantarum 2P and the Bifidobacterium bifidum into the three holes on the same plate respectively, wherein the adding amount of the Lactobacillus rhamnosus ZL-136 bacterial suspension does not overflow the holes, then culturing all the plates in a positive mode, and measuring the diameter of a bacteriostatic ring on each plate after 48 hours to judge the inhibitory effect of the Russian strains (the Lactobacillus rhamnosus ZL-136 bacterial strain, the Lactobacillus plantarum 2P and the Bifidobacterium bifidum) on staphylococcus aureus, escherichia coli, bacillus subtilis, salmonella typhi, Shigella shigella dysenteriae, Shigella bodyii and beta hemolytic streptococcus.

3. Results of the experiment

TABLE 1 bacteriostatic effect of Lactobacillus rhamnosus ZL-136

Indicator bacterium	Average zone diameter (mm)
		Staphylococcus aureus	8.8
Escherichia coli	10.8
		Bacillus subtilis	11.4
Salmonella typhosa	10.6
		Shigella shigella	10.9
Shigella boydii	11.3
		Beta hemolytic streptococcus	9.5

As can be seen from Table 1, Lactobacillus rhamnosus ZL-136 has a wide antibacterial spectrum, has inhibitory activity to Bacillus subtilis, Staphylococcus aureus and beta hemolytic streptococcus in gram-positive bacteria, and also has strong inhibitory activity to Escherichia coli, Salmonella typhi, Shigella shigella and other pathogenic bacteria in gram-negative bacteria, which indicates that Lactobacillus rhamnosus ZL-136 has a good inhibitory effect to gram-positive bacteria and gram-negative bacteria.

TABLE 2 antibacterial Effect of Lactobacillus plantarum 2P

As can be seen from Table 2, the Lactobacillus plantarum 2P of the present invention has no inhibitory effect on gram-negative bacteria, but has a certain inhibitory effect on gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, and beta hemolytic streptococcus.

TABLE 3 bacteriostatic effect of Bifidobacterium bifidum

Indicator bacterium	Average zone diameter (mm)
		Staphylococcus aureus	11.5
Escherichia coli	5.7
		Bacillus subtilis	10.9
Salmonella typhosa	6.6
		Shigella shigella	7.3
Shigella boydii	6.5
		Beta hemolytic streptococcus	10.3

As can be seen from Table 3, the Russian species Bifidobacterium bifidum used in the present invention was able to inhibit all of the above-mentioned indicator bacteria, and it was found by analysis that Bifidobacterium bifidum has a weaker inhibitory activity against gram-negative bacteria (Escherichia coli, Salmonella typhi, Shigella shigella and Shigella baumannii) than against gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus and beta-hemolytic streptococcus), possibly associated with different strain structures.

In conclusion, the three Russian strains selected by the invention have certain bacteriostatic spectra and good inhibitory capacity on pathogenic microorganisms, and can reduce the pollution of pathogenic microorganisms and ensure the health of food when being used in the food.

Second, preparation process of flavored yogurt

S1, weighing the following raw materials by mass: 80g of skimmed milk, 1g of nut additive, 1g of grain additive, 3g of potato modified starch, 7g of white granulated sugar and 1.5% of inoculum size of leavening agent for later use;

the specific preparation steps of the leavening agent are as follows:

respectively activating Lactobacillus rhamnosus ZL-136, Lactobacillus plantarum 2P and Bifidobacterium bifidum, respectively inoculating into MRS liquid culture medium, culturing until bacterial liquid OD₆₀₀Centrifuging at 2000rpm for 10min when the value is 0.7, removing supernatant, collecting thallus, and mixing according to the mass ratio of 1:1:1 to obtain a starter;

the nut additive comprises 0.5g of crushed walnut and 0.5g of crushed pine nut;

0.5g of oat grains and 0.5g of white sesame seeds in the grain additive respectively;

s2, preparing materials: placing fresh bovine colostrum in a heating tank, sterilizing at 90 deg.C for 30min, removing upper layer oil during sterilization to defat milk, and cooling to obtain defatted milk;

uniformly mixing potato modified starch and white granulated sugar, adding the nut additive and the grain additive into the skimmed milk, uniformly mixing, heating to 55 ℃, adding the potato modified starch and the white granulated sugar which are mixed in advance under high-speed stirring, and stirring until the potato modified starch and the white granulated sugar are completely dissolved; the white granulated sugar and the potato modified starch are uniformly added, so that the potato modified starch is prevented from being dispersed unevenly, and the potato modified starch mixed with the white granulated sugar can be uniformly dissolved by adding the white granulated sugar under high-speed stirring;

s3, preheating and homogenizing: in order to improve the homogenizing efficiency, the mixture after complete dissolution is heated to 45 ℃, preheated for 25min and then homogenized under 20Mpa at 70 ℃;

s4, sterilization: sterilizing at 95 deg.C for 300s after homogenizing to obtain sterile nutritious milk;

s5, inoculating and fermenting: inoculating 1.5% of the starter in sterile nutritional milk, sealing and fermenting for 10h, and fermenting at 4 deg.C for 96h to obtain flavored yogurt.

The obtained flavored yogurt can be preserved for 30 days at 4 deg.C.

Example 2:

the embodiment provides a preparation method of flavored yogurt, which basically comprises the following specific steps of example 1:

s1, the flavored yogurt is prepared from the following raw materials: 70g of skimmed milk, 1g of nut additive, 1g of grain additive, 2g of potato modified starch, 6g of white granulated sugar and 1% of inoculum size;

s2, adding the nut additive and the grain additive into the skimmed milk, and heating to 50 ℃;

in S3, preheating at 40 deg.C for 30min, and homogenizing at 18Mpa and 75 deg.C;

in S5, the starter culture is inoculated in an amount of 1%, sealed and fermented for 8h, and then fermented for 94h at 4 ℃.

Example 3:

the embodiment provides a preparation method of flavored yogurt, which basically comprises the following specific steps of example 1:

s1, the flavored yogurt is prepared from the following raw materials: 90g of skimmed milk, 2g of nut additive, 2g of grain additive, 4g of potato modified starch, 8g of white granulated sugar and 3% of inoculum size;

the nut additive comprises 1g of crushed walnut and 1g of crushed pine nut;

1g of oat grains and 1g of white sesame seeds in the grain additive respectively;

s2, adding the nut additive and the grain additive into the skimmed milk, and heating to 60 ℃;

in S3, preheating at 50 deg.C for 20min, and homogenizing at 20Mpa and 65 deg.C;

in S5, the inoculum size of the starter is 3%, the fermentation is carried out for 12h in a sealed way, and then the fermentation is carried out for 98h at 4 ℃.

Sensory evaluation description is carried out on the taste, color and smell of the flavor yoghourt prepared in the embodiment 1-3, 60 volunteers are selected for evaluation and comment scoring, and the average score is the final score of the sample. The sensory evaluation test was conducted according to the sensory evaluation criteria shown in table 1.

TABLE 1 sensory evaluation criteria for flavored yoghurts

A summary of sensory evaluations is reported in table 2.

TABLE 2 summary table of sensory evaluations of flavored yoghurts prepared in accordance with the present invention

Examples	Taste smell	Color	Form of the composition
				Example 1	9.92	9.7	9.93
Example 2	9.77	9.56	9.25
				Practice ofExample 3	9.41	9.37	9.83

The nutritional components of the flavored yogurt were measured and recorded in Table 3, and the hygiene index of the flavored yogurt prepared in example 1 was measured and recorded in Table 4, using example 1 as an example

TABLE 3 partial Nutrition ingredient Table (100g) of flavored yogurt prepared in example 1

Index (I)	The mass percentage of each nutrient component in each 100g of the flavored yogurt (%)
		Protein	3.2％
Fat	1.5％
		Vitamin E	0.01％
Vitamin C	0.66％

TABLE 4 sanitation index of flavored yogurt prepared in example 1

Item	Index (I)	Measured value	Evaluation of
				Escherichia coli (MPN/100g)	≤3	<1	Qualified

The results show that the flavor yoghourt prepared by the invention has smooth and full mouthfeel, good fluidity, direct drinking and high nutritive value.

To sum up, the bovine colostrum product obtained by the application is very beneficial to the postoperative patient, provides a large amount of immunoglobulin for the organism, enhances the immunity, promotes the quick healing of the postoperative wound, and prevents infection.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.