Strain composition and application thereof in 0-sucrose flavored fermented milk

Abstract

The invention provides a strain composition and application thereof in 0-sucrose flavored fermented milk. The strain composition is prepared from a medium-temperature fermentation bacterium XPL-30, a texture improving bacterium ST-BODY-3 and a shelf life preservation bacterium CR-319. According to the strain composition provided by the invention, the medium-temperature bacterium XPL-30 is used as a main leavening agent, and meanwhile, the texture improving bacterium ST-BODY-3 and the shelf fresh-keeping bacterium CR-319 are assisted to participate in the fermentation process together, so that extremely weak post-acidification and proper product texture and flavor are realized. The strain composition also can prolong the enzymolysis time of lactase, ensure thorough enzymolysis, reduce the dosage of lactase and save the cost.

Description

Technical Field

[0001] The present invention relates to the technical field of dairy product fermentation, and in particular to a bacterial composition and application thereof in zero-sucrose flavored fermented milk. Background Art

[0002] Reducing sugar in yogurt products is an initiative that the industry is currently pursuing and that meets consumer demand. Zero sucrose flavored fermented milk refers to a product formula that does not add white sugar, thereby achieving the purpose of reducing sugar. However, in order to ensure a better taste, some products will add additional sweeteners and sugar alcohols to make up for the sweetness lost due to sugar reduction. Products with pure sugar reduction taste inferior to ordinary products, but products that add sweeteners to supplement the sweetness after sugar reduction will give consumers an intuitive feeling of being unhealthy and unnatural in the ingredient list. How to increase the sweetness of the product on the basis of a formula with zero sucrose and no added sweeteners, improve the product's sweet and sour balance, enrich the product's taste, give the product a new sensory experience in sourness, sweetness and texture, and achieve the delicious enjoyment of zero sucrose and no additions is a major problem in this field.

[0003] Existing research has provided zero-sucrose coagulated fermented milk without food additives through formula optimization and process improvement. For example, the zero-sucrose yogurt of invention CN202111238744.3 does not use sweeteners. The raw materials of its fermented milk include WPC30 / 8 whey protein powder, YO-5215 whey protein powder, etc. The selected whey protein powder needs to be specially pretreated and the homogenization pressure needs to be reduced, and the lactase needs to be enzymatically hydrolyzed as a separate ingredient, which adds a production process and reduces production efficiency. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a bacterial strain composition and its application in zero-sucrose flavored fermented milk.

[0005] In a first aspect, the present invention provides a bacterial strain composition, which comprises medium-temperature fermentation bacteria XPL-30, texture-improving bacteria ST-BODY-3, and shelf-preserving bacteria CR-319.

[0006] The bacterial composition provided in the present invention, XPL-30 is a mesophilic homotypic fermentation mixed bacterial species, mainly used for processing cheese products, fermented sour cream and Kefir-type products. The present invention uses the mesophilic bacteria XPL-30 as the main fermentation agent, and simultaneously supplements the texture-improving bacteria ST-BODY-3 and the shelf-keeping bacteria CR-319 to participate in the fermentation process, thereby achieving extremely weak post-acidity and suitable product texture and flavor. The mesophilic fermentation bacteria XPL-30, the texture-improving bacteria ST-BODY-3, and the shelf-keeping bacteria CR-319 are slow fermented, which can prolong the enzymolysis time of lactase, ensure thorough enzymolysis, appropriately reduce the amount of lactase used, and save costs.

[0007] Preferably, the mass ratio of the medium-temperature fermentation bacteria XPL-30, the texture-improving bacteria ST-BODY-3 and the shelf-preserving bacteria CR-319 is 1-4:1-2:1-2, preferably 1-3:1:1.

[0008] The present invention obtains a strain composition of mesophilic fermentation bacteria XPL-30, texture-improving bacteria ST-BODY-3 and shelf-keeping bacteria CR-319 by scientifically combining and researching the strain composition through cross-category strain matching and combination. By selecting the mesophilic bacteria XPL-30 used in the cheese processing process at an optimal ratio for fermentation, yogurt with a strong cheese aroma can be further obtained. By selecting the optimal ratio of CR-319, undesirable flavor substances can be further modified during the shelf life of the product to obtain a purer and more natural milk aroma. By using the optimal ratio of ST-BODY-3, the viscosity of the product can be further increased, the texture can be improved, and the taste of the product can be enriched.

[0009] In a second aspect, the present invention provides the use of the bacterial composition in the preparation of zero-sucrose flavored fermented milk.

[0010] According to the present invention, the fermenting bacteria in the flavored fermented milk products are generally thermophilic streptococci and bulgaricus lactobacillus. The present invention breaks the convention and studies the application and innovation of a bacterial composition in flavored fermented milk products. First, the mesophilic bacteria XPL-30 commonly used in the cheese making process is selected as the main fermentation agent of the 0 sucrose flavored fermented milk product for yogurt fermentation, which produces weak acid and soft post-acid. At the same time, the slime-producing bacteria ST-BODY-3 is used to increase the viscosity of the product, improve the texture, and enrich the taste of the product. The shelf-keeping bacteria CR-319 is used to modify the bad flavor and post-acid during the shelf life of the product to ensure a pure and natural milk flavor.

[0011] Preferably, the addition amount of the medium-temperature fermentation bacteria XPL-30 is 100-200 U / t; and / or, the addition amount of the texture-improving bacteria ST-BODY-3 is 50-100 U / t; and / or, the addition amount of the shelf-keeping bacteria CR-319 is 50-100 U / t.

[0012] Preferably, the mass ratio of the texture improving bacteria ST-BODY-3 to the shelf-preserving bacteria CR-319 is 1-2:1-2, preferably 1:1.

[0013] The inventors found that in order to ensure the balance of sweetness and sourness, texture and milky aroma of the product, the addition amount of the above three strains and the ratio between the three are also very important. The addition amount of XPL-30 is 100-200U / t, the addition amount of ST-BODY-3 and CR-319 is 50-100U / t respectively, and the addition effect of ST-BODY-3 and CR-319 in the preferred ratio, especially 1:1, is best.

[0014] The third invention is a zero-sucrose flavored fermented milk without added sweeteners provided by the present invention, comprising raw cow's milk, lactase and a bacterial composition, wherein the bacterial composition is the bacterial composition or the bacterial composition in the application of the bacterial composition in the preparation of zero-sucrose flavored fermented milk.

[0015] The present invention uses lactase to enzymolyze the lactose in milk itself, decomposing it into glucose and galactose, giving the product a sweet feeling. The inventor further found that lactase can be added in the batching link to enzymolyze the lactose in milk alone, but it will increase the production process and reduce production efficiency. The lactase in the present invention is added simultaneously with the specific bacterial composition in the yogurt inoculation link, and the enzymolysis reaction occurs synchronously during the fermentation process, but most lactases are sensitive to acid, and the enzyme loses activity when the yogurt is fermented to pH 5.5 or below. The scheme of the present invention combines the characteristics of the bacterial composition, selects the mesophilic bacteria XPL-30, studies its fermentation temperature and inoculation amount, slows down the fermentation speed, and prolongs the lactase enzymolysis reaction time to ensure that the lactose is thoroughly decomposed. The addition amount of XPL-30 is 100-200U / t, and when the fermentation temperature is between 35-38°C, the time for yogurt to ferment to pH 5.5 can be extended to more than 5h (the time for ordinary yogurt to ferment to pH 5.5 is about 2h). In addition, while the enzymatic hydrolysis time is prolonged, the amount of lactase used can be appropriately reduced to save costs. The amount of lactase used can be reduced from 0.4g / t to 0.2g / t. The inventors have found that for zero sucrose products, excessive addition of lactase can lead to poor product stability, and particles are likely to appear in the product after decooling during the shelf life.

[0016] Preferably, the addition amount of the medium-temperature fermentation bacteria XPL-30 is 100-200 U / t, the addition amount of the texture-improving bacteria ST-BODY-3 is 50-100 U / t, and the addition amount of the shelf-preserving bacteria CR-319 is 50-100 U / t.

[0017] Preferably, the mass ratio of the texture-improving bacteria ST-BODY-3 to the shelf-keeping bacteria CR-319 is 1 to 2: 1 to 2, preferably 1: 1. Further preferably, the mass ratio of the mesophilic fermentation bacteria XPL-30, the texture-improving bacteria ST-BODY-3, and the shelf-keeping bacteria CR-319 is 2 to 3: 1: 1.

[0018] Preferably, the ratio of the added amount of the raw milk to the lactase is 99.9:0.1 to 99.98:0.02; preferably 999.6:0.4 to 999.8:0.2.

[0019] The invention optimizes the amount of lactase added. Conventional yogurt ferments faster and the lactase reaction time is short. The invention utilizes the characteristics of the strain to extend the fermentation time and reduce the amount of lactase used.

[0020] In a fourth aspect, the present invention provides a method for preparing the zero-sucrose flavored fermented milk without adding sweeteners, comprising the steps of concentrating, homogenizing and sterilizing raw milk, and then adding lactase and a bacterial composition for fermentation.

[0021] The present invention optimizes the lactase addition process. Conventional lactase is added in the batching process to enzymolyze lactose in milk alone, but it increases the production process and reduces production efficiency. In the present invention, lactase and bacterial composition are added simultaneously to improve production efficiency. The present invention adopts the combination of lactase and special bacterial species and optimizes the synchronous addition method. Through the interaction of lactase, bacterial composition and its metabolites, the bacterial species are slowly fermented, the lactose enzymolysis time is extended, the enzymolysis is sufficient, and the sweetness, texture and flavor are further improved.

[0022] According to a preferred embodiment of the present invention, the method for preparing the zero-sucrose flavored fermented milk comprises:

[0023] 1) Concentration: RO membrane filtration is performed on the raw milk to obtain concentrated raw milk with a protein index of 3.6% to 4.5% and a lactose content of ≥5.0%;

[0024] 2) Homogenization: Homogenize the concentrated raw milk, control the homogenization temperature at 55-65°C, control the homogenization pressure at 4-5MPa for the second level and 15-16MPa for the first level;

[0025] 3) Sterilization: sterilize the liquid after homogenization in step 2) at a temperature of 92 to 98° C. for 300 to 330 seconds;

[0026] 4) Cooling: The sterilized liquid is cooled to 35-38°C;

[0027] 5) Fermentation: adding strains XPL-30, ST-BODY-3, CR-319 and lactase to the liquid cooled in step 4), and fermenting at 35-38° C. for 5-9 hours;

[0028] 6) Demulsification: Demulsification is performed when the pH value of fermentation reaches 4.50-4.65, and a dynamic smoothing pump is used to obtain a uniform and delicate fermented milk;

[0029] 7) Cooling: Cooling the liquid after the smoothing treatment in step 6) to 16-20° C.;

[0030] 8) Filling and storage: The fermented milk cooled in step 7) is filled and transferred to a cold storage at 2-10° C. for post-ripening.

[0031] Preferably, the method for preparing the above-mentioned sweetener-free 0-sucrose flavored fermented milk comprises concentrating raw milk, and the concentration is carried out by RO membrane filtration; more preferably, the protein index of the concentrated raw milk is 3.6% to 4.5%, and the lactose content is 5.0% to 7.0%.

[0032] The present invention uses RO membrane concentration and separation technology to concentrate raw milk and enrich lactose, so that the lactose and protein in the concentrated milk are at a certain concentration to facilitate the subsequent fermentation and enzymatic hydrolysis effect. After concentration, the protein index of the milk is between 3.6% and 4.5%, and the lactose content is 5.0% to 7.0%, which increases the substrate of the enzymatic hydrolysis reaction of lactase, obtains more glucose through enzymatic hydrolysis, and enhances the sweetness.

[0033] The beneficial effect of the present invention is at least that: the bacterial composition of the present invention uses the mesophilic bacteria XPL-30 as the main fermentation agent, and is supplemented by texture-improving bacteria and shelf-keeping bacteria to participate in the fermentation process, thereby achieving extremely weak post-acidity and suitable product texture and flavor. The mesophilic fermentation bacteria XPL-30, texture-improving bacteria ST-BODY-3, and shelf-keeping bacteria CR-319 used in the present invention are slow fermented, which can prolong the enzymolysis time of lactase, ensure thorough enzymolysis, appropriately reduce the amount of lactase used, and save costs. Based on the formula of 0 sucrose and no sweeteners, scientific methods are adopted to focus on the fermentation process of bacterial strains. The product's post-acidity is weakened and the product texture is improved through the combination of multiple bacterial strains. Lactase enzymatic hydrolysis reaction is introduced during the fermentation process to bring sweetness to the product. At the same time, the lactase addition method is optimized in combination with the fermentation characteristics of the bacterial strains, and measures such as concentrated milk enrichment of lactose are taken to improve the product's sweet-sour balance, enrich the product's taste, and give the product a new sensory experience in sourness, sweetness and texture, so as to achieve the purpose of 0 sucrose and no addition and still delicious, while providing consumers with a healthy and natural choice. In addition, the improvement of the bacterial strain and lactase addition process in the present invention can improve production efficiency and save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 Schematic diagram of the tissue states of Examples 1 to 4 of the present invention and Comparative Examples 1 to 3;

[0036] Figure 2 This is a schematic diagram of the stability of the product at the end of the shelf life at a low temperature of 2 to 10° C. according to Example 3 of the present invention;

[0037] Figure 3It is a schematic diagram of the preference degree of Example 3 of the present invention and commercially available products. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the examples of the present invention, the sources of the mesophilic bacteria, texture-improving bacteria and fresh-keeping bacteria used are: strain FD-DVS XPL-30, strain FD-DVS ST-BODY-3 and strain F-DVS CR-319 purchased from Chr. Hansen, respectively.

[0040] Example 1

[0041] The present embodiment provides a bacterial strain composition and a 0-sucrose flavored fermented milk without adding sweeteners prepared by using the bacterial strain composition, wherein the raw materials are added in the following amounts by weight: 999.8 parts of raw cow's milk, 0.2 parts of lactase, 100U / t of bacterial strain XPL-30 (mesophilic bacteria), 100U / t of bacterial strain ST-BODY-3 (texture improving bacteria), and 100U / t of bacterial strain CR-319 (fresh-keeping bacteria).

[0042] The present invention also provides a method for preparing the 0-sucrose flavored fermented milk, which is specifically:

[0043] 1) Concentration: RO membrane filtration is performed on the raw milk to obtain concentrated raw milk with a protein index of 3.6% to 4.0% and a lactose content of 5.0% to 7.0%;

[0044] 2) Homogenization: Homogenize the concentrated raw milk, the homogenization temperature is controlled at 60°C, the homogenization pressure is controlled at 4MPa for the second stage and 16MPa for the first stage;

[0045] 3) Sterilization: sterilize the liquid after homogenization in step 2) at a temperature of 95° C. for 300 seconds;

[0046] 4) Cooling: The sterilized liquid is cooled to 37°C;

[0047] 5) Fermentation: Add strains XPL-30, ST-BODY-3, CR-319 and lactase to the liquid cooled in step 4), and start fermentation at 37° C. for 9 hours;

[0048] 6) Demulsification: Demulsification is performed when the pH value of the fermentation reaches 4.6, and a dynamic smoothing pump is used to obtain a uniform and delicate fermented milk;

[0049] 7) Cooling: Cooling the liquid after the smoothing treatment in step 6) to 18° C.;

[0050] 8) Filling and storage: The fermented milk cooled in step 7) is filled and transferred to a cold storage at 2-10° C. for post-ripening.

[0051] Example 2

[0052] The present embodiment provides a bacterial strain composition and a 0-sucrose flavored fermented milk without adding sweeteners prepared by using the bacterial strain composition, wherein the raw materials are added in the following amounts by weight: 999.8 parts of raw cow's milk, 0.2 parts of lactase, 200U / t of bacterial strain XPL-30 (mesophilic bacteria), 100U / t of bacterial strain ST-BODY-3 (texture improving bacteria), and 100U / t of bacterial strain CR-319 (fresh-keeping bacteria).

[0053] The present invention also provides a method for preparing the 0-sucrose flavored fermented milk, which is specifically:

[0054] 1) Concentration: RO membrane filtration is performed on the raw milk to obtain concentrated raw milk with a protein index of 3.6% to 4.5% and a lactose content of 5.0% to 7.0%;

[0055] 2) Homogenization: Homogenize the concentrated raw milk, the homogenization temperature is controlled at 60°C, the homogenization pressure is controlled at 4MPa for the second stage and 16MPa for the first stage;

[0056] 3) Sterilization: sterilize the liquid after homogenization in step 2) at a temperature of 95° C. for 300 seconds;

[0057] 4) Cooling: The sterilized liquid is cooled to 35°C;

[0058] 5) Fermentation: Add strains XPL-30, ST-BODY-3, CR-319 and lactase to the liquid cooled in step 4) and start fermentation for 9 hours;

[0059] 6) Demulsification: Demulsification is performed when the fermentation reaches pH 4.6, and a dynamic smoothing pump is used to obtain a uniform and delicate fermented milk;

[0060] 7) Cooling: Cooling the liquid after the smoothing treatment in step 6) to 18° C.;

[0061] 8) Filling and storage: The fermented milk cooled in step 7) is filled and transferred to a cold storage at 2-10° C. for post-ripening.

[0062] Example 3

[0063] The present embodiment provides a bacterial strain composition and a 0-sucrose flavored fermented milk without adding sweeteners prepared by using the bacterial strain composition, wherein the raw materials are added in the following amounts by weight: 999.6 parts of raw cow's milk, 0.4 parts of lactase, 100U / t of bacterial strain XPL-30 (mesophilic bacteria), 50U / t of bacterial strain ST-BODY-3 (texture improving bacteria), and 50U / t of bacterial strain CR-319 (fresh-keeping bacteria).

[0064] The present invention also provides a method for preparing the 0-sucrose flavored fermented milk, which is specifically:

[0065] 1) Concentration: RO membrane filtration is performed on the raw milk to obtain concentrated raw milk with a protein index of 4.0% to 4.5% and a lactose content of 5.0% to 7.0%;

[0066] 2) Homogenization: Homogenize the concentrated raw milk, the homogenization temperature is controlled at 60°C, the homogenization pressure is controlled at 4MPa for the second stage and 16MPa for the first stage;

[0067] 3) Sterilization: sterilize the liquid after homogenization in step 2) at a temperature of 95° C. for 300 seconds;

[0068] 4) Cooling: The sterilized liquid is cooled to 37°C;

[0069] 5) Fermentation: Add strains XPL-30, ST-BODY-3, CR-319 and lactase to the liquid cooled in step 4) and start fermentation for 9 hours;

[0070] 6) Demulsification: Demulsification is performed when the fermentation reaches pH 4.6, and a dynamic smoothing pump is used to obtain a uniform and delicate fermented milk;

[0071] 7) Cooling: Cooling the liquid after the smoothing treatment in step 6) to 18° C.;

[0072] 8) Filling and storage: The fermented milk cooled in step 7) is filled and transferred to a cold storage at 2-10° C. for post-ripening.

[0073] Example 4

[0074] The present embodiment provides a bacterial strain composition and a 0-sucrose flavored fermented milk without adding sweeteners prepared by using the bacterial strain composition, wherein the raw materials are added in the following amounts by weight: 999.8 parts of raw cow's milk, 0.2 parts of lactase, 150U / t of bacterial strain XPL-30 (mesophilic bacteria), 50U / t of bacterial strain ST-BODY-3 (texture improving bacteria), and 50U / t of bacterial strain CR-319 (fresh-keeping bacteria).

[0075] The present invention also provides a method for preparing the 0-sucrose flavored fermented milk, which is specifically:

[0076] 1) Concentration: RO membrane filtration is performed on the raw milk to obtain concentrated raw milk with a protein index of 4.0% to 4.5% and a lactose content of 5.0% to 7.0%;

[0077] 2) Homogenization: Homogenize the concentrated raw milk, the homogenization temperature is controlled at 60°C, the homogenization pressure is controlled at 4MPa for the second stage and 16MPa for the first stage;

[0078] 3) Sterilization: sterilize the liquid after homogenization in step 2) at a temperature of 95° C. for 300 seconds;

[0079] 4) Cooling: The sterilized liquid is cooled to 37°C;

[0080] 5) Fermentation: Add strains XPL-30, ST-BODY-3, CR-319 and lactase to the liquid cooled in step 4) and start fermentation for 9 hours;

[0081] 6) Demulsification: Demulsification is performed when the fermentation reaches pH 4.6, and a dynamic smoothing pump is used to obtain a uniform and delicate fermented milk;

[0082] 7) Cooling: Cooling the liquid after the smoothing treatment in step 6) to 18° C.;

[0083] 8) Filling and storage: The fermented milk cooled in step 7) is filled and transferred to a cold storage at 2-10° C. for post-ripening.

[0084] Comparative Example 1

[0085] The same method as in Example 1 was used, except that the strains ST-BODY-3 (texture improving bacteria) and CR-319 (fresh-keeping bacteria) were not added.

[0086] Comparative Example 2

[0087] The same method as in Example 1 was used, except that lactase was not added.

[0088] Comparative Example 3

[0089] The same method as in Example 1 was used, except that the added bacterial composition was changed to fermentation bacteria Premium 11 (added at 100 U / t) and strain CR-319 (added at 50 U / t).

[0090] The present invention tests the taste, sweetness and sourness, texture and stability of Examples 1 to 4 and Comparative Examples 1 to 3, wherein the stability is mainly evaluated on the tissue state of the product under the condition of product decooling (30° C. insulation chamber), and the taste, sweetness and sourness and texture are mainly tested by physical and chemical testing and professional sensory tasters. The specific results are as follows:

[0091] Table 1 Performance test results of Examples 1 to 4 and Comparative Examples 1 to 3

[0092]

[0093] Table 2 Performance test results of Example 1 and Comparative Example 3

[0094]

[0095]

[0096]

[0097] The zero sucrose yogurt prepared in Example 3 of the present invention has lower acidity, a suitable viscosity range, better flavor and taste, and a stable shelf life compared with commercially available products 1 to 4, and is a natural and healthy choice for zero sucrose yogurt.

[0098] 1) Balance of sweet and sour

[0099] The pH value of the yogurt prepared in Example 3 of the present invention is basically around 4.5 during the shelf life at 2-6°C (as shown in Table 3), with little overall fluctuation, and is significantly higher than commercially available products; the acidity value is between 78-88°T (as shown in Table 4), which is significantly lower than commercially available products, and the sweet and sour taste is better than commercially available products.

[0100] Table 3 Performance test results of Example 3 and commercially available products 1 to 3

[0101]

[0102] Table 4 Performance test results of Example 3 and commercially available products 1 to 3

[0103]

[0104] 2) Product texture

[0105] For 0-sucrose yogurt, in addition to sweetness and sourness, texture is also one of the important indicators that affect consumer preference. In order to better meet consumer needs, this project produced 6 products with different viscosity indicators for consumer testing, investigated the corresponding yogurt viscosity range under different product concepts, and concluded that products with a viscosity of about 800mpa.s are more easily accepted by consumers.

[0106] In the industrial production process of yogurt, due to the long production equipment and pipeline layout, the shear force is too large, which may cause a large loss of viscosity of the yogurt product. Especially for mesophilic bacteria, the texture of the product after fermentation is thin and not shear-resistant. The present invention increases ST-BODY-3 participation in fermentation through bacterial compounding, produces more extracellular polysaccharides, improves product texture, and realizes that the product viscosity is increased from about 500mpa.s to about 900mpa.s.

[0107] Table 5 Product viscosity

[0108] Product No. Approximate viscosity value (mpa.s) A ＜50 B 200 C 400 D 800 E 1200 F 4000

[0109] Table 6 Consumer survey-product texture matching test results

[0110]

[0111]

[0112] 3) Product status

[0113] Sucrose provides an indispensable support for the texture and stability of fermented yogurt, so there is an inherent disadvantage in the stability of zero sucrose products. For the zero sucrose yogurt in the present invention, in-depth research is conducted on the metabolic characteristics of bacteria in different stages of the yogurt fermentation process and the product shelf life to ensure the stability of the product texture and the consistency of quality. The stability of the product made in Example 3 of the present invention at the end of the shelf life (21 days) under low temperature conditions of 2 to 10°C is shown in the following figure. Figure 2 shown.

[0114] 4) Product sensory

[0115] Table 7 shows the professional description test results of Example 3 of the present invention and the commercially available products. Within the 90% confidence interval, the differences among the four products are mainly reflected in the texture attributes. The textures of Example 3 and Commercially Available Product 1 are similar, and slightly thicker than the other two products; the smoothness of Example 3 is significantly better than the other three products, among which Commercially Available Product 1 and Commercially Available Product 3 have obvious powdery feel; the milk flavor score of Example 3 is the highest, and is significantly better than Commercially Available Product 1; the acidity of Example 3 is significantly lower than that of Commercially Available Product 3. In addition, after the final consumer test, Example 3 (this product) received a higher degree of preference, as shown in FIG. Figure 3 shown.

[0116] Table 7 Product professional sensory test results

[0117]

[0118]

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bacterial composition, It is characterized in that The bacterial composition comprises medium-temperature fermentation bacteria XPL-30, texture-improving bacteria ST-BODY-3 and shelf-keeping bacteria CR-319.

2. The bacterial composition according to claim 1, It is characterized in that The mass ratio of medium-temperature fermentation bacteria XPL-30, texture-improving bacteria ST-BODY-3 and shelf-preserving bacteria CR-319 is 1-4:1-2:1-2.

3. Use of the bacterial composition according to claim 1 or 2 in the preparation of zero-sucrose flavored fermented milk.

4. A 0-sucrose flavored fermented milk without adding sweeteners, It is characterized in that The invention comprises raw cow milk, lactase and a bacterial composition, wherein the bacterial composition is the bacterial composition according to claim 1 or 2.

5. The zero-sucrose flavored fermented milk without adding sweetener according to claim 4, It is characterized in that The mass ratio of the raw milk to the lactase added is 99.9:0.1 to 99.98:0.

02.

6. The zero-sucrose flavored fermented milk without adding sweetener according to claim 4 or 5, It is characterized in that The addition amount of the medium-temperature fermentation bacteria XPL-30 is 100-200 U / t, the addition amount of the texture-improving bacteria ST-BODY-3 is 50-100 U / t, and the addition amount of the shelf-keeping bacteria CR-319 is 50-100 U / t.

7. The zero-sucrose flavored fermented milk without adding sweetener according to claim 4 or 5, It is characterized in that The mass ratio of the texture improving bacteria ST-BODY-3 to the shelf-keeping bacteria CR-319 is 1-2:1-2, preferably 1:

1.

8. The zero-sucrose flavored fermented milk without adding sweetener according to claim 4 or 5, It is characterized in that The ratio of the added amount of the raw milk to the added amount of the lactase is 99.9:0.1 to 99.98:0.02; preferably 999.6:0.4 to 999.8:0.

2.

9. The method for preparing the zero-sucrose flavored fermented milk without adding sweetener according to any one of claims 4 to 8, It is characterized in that The method comprises the steps of concentrating, homogenizing and sterilizing raw milk, and then adding lactase and a bacterial composition for fermentation.

10. The method for preparing the zero-sucrose flavored fermented milk without adding sweetener according to claim 9, It is characterized in that The method comprises concentrating raw cow milk, wherein the concentration is carried out by RO membrane filtration; preferably, the protein index of the concentrated raw cow milk is 3.6% to 4.5%, and the lactose content is 5.0% to 7.0%.

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