Bifidobacterium-containing fermented milk with good microrheology property and preparation method thereof

Abstract

The invention relates to the technical field of probiotic leavening agents, in particular to fermented milk containing bifidobacteria with good microrheology characteristics and a preparation method of the fermented milk. The probiotic leavening agent provided by the invention is composed of an auxiliary leavening agent, a basic leavening agent and active probiotics, the auxiliary leavening agent is prepared from lactococcus lactis IMAU11823 (preserved in China General Microbiological Culture Collection Center, with the preservation number of CGMCC 16243), and the basic leavening agent is prepared from lactococcus lactis IMAU11823 (preserved in China General Microbiological Culture Collection Center, with the preservation number of CGMCC 16243). The active probiotic fermentation agent is prepared from bifidobacterium animalis subsp. Lactis Cai-4 (preserved in China General Microbiological Culture Collection Center (CGMCC), and the preservation number is CGMCC No.31691), and the fermentation agent matrix is milk.

Description

Technical Field

[0001] The invention belongs to the technical field of probiotic fermentation agents, and particularly relates to a method for preparing bifidobacterium fermented milk with good microrheological properties. Background Art

[0002] Probiotic fermented milk is favored by consumers because of its dual health benefits of probiotics and fermented dairy products, with an average annual growth rate of more than 10%. Bifidobacterium is not only a common beneficial microorganism in the human intestine, but also commonly used in the production of probiotic fermented milk because of its effects on relieving diarrhea and constipation and enhancing immunity. Animal Bifidobacterium lactis subspecies Cai-4 is a strain of bifidobacteria with excellent characteristics isolated from kimchi. Lactococcus lactis IMAU11823 is a lactic acid bacterium with good fermentation characteristics isolated from the chewing of traditional fermented dairy products of the Xilin Gol Mongolian people in 2016. Lactococcus lactis IMAU11823 has a complete exopolysaccharide gene cluster, which can produce relatively complex exopolysaccharides, giving the product good texture characteristics. It has good application prospects as an auxiliary fermentation agent.

[0003] Fermented milk has a complex gel structure, and its gel structure has a great influence on texture and sensory perception, affecting the sales volume of fermented milk products in market competition and the preference and acceptance of consumers. Bifidobacteria survive in fermented milk and metabolize lactose to produce lactic acid, which usually inhibits the growth of Lactobacillus bulgaricus and Streptococcus thermophilus, which is not conducive to obtaining good texture characteristics. The present invention aims to provide a method for preparing bifidobacterium fermented milk with good microrheological properties. Summary of the invention

[0004] To solve the above problems, the present invention provides a method for preparing bifidobacterium fermented milk with good microrheological properties, aiming to provide people with a fermented milk product with a high number of viable probiotics and good sensory quality.

[0005] In a first aspect, in order to achieve the above-mentioned objectives, the present application provides a probiotic fermentation agent having good microrheological properties.

[0006] Probiotic fermentation agent is composed of basic fermentation agent, auxiliary fermentation agent and active probiotics.

[0007] Among them, the basic fermentation agent is a commercially available fermentation agent, the auxiliary fermentation agent is Lactococcus lactis IMAU11823 (preserved in the China National Microbiological Culture Collection Center, with the collection number CGMCC 16243), the active probiotics are Bifidobacterium animalis subspecies Cai-4 (preserved in the China National Microbiological Culture Collection Center, with the collection number CGMCC No.31691), and the basic fermentation agent contains Lactobacillus bulgaricus and Streptococcus thermophilus.

[0008] By adopting the above technical scheme, the basic starter in the probiotic starter can quickly produce acid and viscosity and give the fermented milk a unique taste, and the auxiliary starter Lactococcus lactis IMAU11823 can quickly produce viscosity and give the fermented milk good texture characteristics and sensory characteristics; the probiotics in the probiotic starter are animal Bifidobacterium lactis subspecies Cai-4, which not only has multiple probiotic properties such as regulating intestinal flora and immunity, but also can significantly improve the microrheological properties of fermented milk when used in combination with Lactococcus lactis IMAU11823.

[0009] Furthermore, the ratio of the viable counts of Lactococcus lactis IMAU11823 and Bifidobacterium animalis subsp. lactis Cai-4 is 1:10-10:1.

[0010] In a second aspect, a fermented milk is provided, which is obtained by adding the probiotic fermentation agent to animal milk for fermentation, wherein the probiotic fermentation agent includes a basic fermentation agent, an auxiliary fermentation agent and active probiotics, the basic fermentation agent contains Lactobacillus bulgaricus and Streptococcus thermophilus, the auxiliary fermentation agent is Lactococcus lactis IMAU11823, and the active probiotics are Bifidobacterium animalis subspecies lactis Cai-4.

[0011] Furthermore, the ratio of the number of live bacteria of Lactococcus lactis IMAU11823 and Bifidobacterium animalis subspecies lactis Cai-4 is 1:100-100:1; 1:90-90:1; 1:80-80:1; 1:70-70:1; 1:60-60:1; 1:50-50:1; 1:40-40:1; 1:30-30:1; 1:20-20:1; 1:10-10:1.

[0012] Furthermore, the amount of auxiliary fermentation agent and active probiotics added was 1.0×10 5 -1.0×10 12 CFU / mL, preferably 1.0×10 5 -1.0×10 11 CFU / mL, preferably 1.0×10 6 -1.0×10 10 CFU / mL, preferably 1.0×10 6 -1.0×10 9 CFU / mL, preferably 1.0×10 6 -1.0×10 8 CFU / mL, preferably 1.0×10 7 CFU / mL.

[0013] Furthermore, the addition amount of the basic leavening agent is 0.01‰-0.05‰ (weight percentage), preferably 0.02‰-0.04‰ (weight percentage).

[0014] Furthermore, the amount of auxiliary fermentation agent added was 1.0×10 5 -1.0×10 12 CFU / mL preferably 1.0×10 5 -1.0×10 11 CFU / mL, preferably 1.0×10 6 -1.0×10 10 CFU / mL, preferably 1.0×10 6 -1.0×10 9 CFU / mL, preferably 1.0×10 6 -1.0×10 8 CFU / mL.

[0015] Furthermore, the amount of active probiotics added was 1.0×10 5 -1.0×10 12 CFU / mL, 1.0×10 5 -1.0×10 11 CFU / mL, preferably 1.0×10 6 -1.0×10 10 CFU / mL, preferably 1.0×10 6 -1.0×10 9 CFU / mL, preferably 1.0×10 6 -1.0×10 8 CFU / mL.

[0016] In a third aspect, the present application provides a bifidobacterium fermented milk with good microrheological properties and a preparation method thereof, characterized in that it comprises the following steps: adding a probiotic starter to sterilized cow's milk and fermenting to obtain fermented milk.

[0017] Furthermore, the fermentation time is 5-10 hours, preferably 6-9 hours, preferably 6-8 hours.

[0018] On the other hand, the present application provides use of a probiotic starter for preparing fermented milk.

[0019] Furthermore, the probiotic fermentation agent is used for preparing milk fermented milk.

[0020] In summary, the positive and progressive effects of the present invention are: The starter combination obtained by screening in the present invention significantly enhances the microrheological properties of fermented milk, thereby optimizing its sensory quality and improving its market competitiveness. This innovative achievement not only provides a solid scientific basis for the innovative development of fermented milk, but also opens up new possibilities for the production of probiotic fermented milk.

[0021] In the present application, by introducing animal Bifidobacterium lactis subspecies Cai-4 and Lactococcus lactis IMAU11823 into the basic starter (PSY-010), we successfully improved the microrheological properties of fermented milk. Compared with the basic starter to which only animal Bifidobacterium lactis subspecies Cai-4 is added, or compared with the combination of Lactococcus lactis IMAU11823 and / or Lactococcus lactis BL-19 added after Cai-4 is added, the starter combination of the present application exhibits better microrheological properties during the fermentation process. It can be seen that the combined use of Bifidobacterium lactis subspecies Cai-4 and Lactococcus lactis IMAU11823 does not inhibit the growth of Lactobacillus bulgaricus and Streptococcus thermophilus, and is also conducive to obtaining fermented milk with good texture characteristics.

[0022] It is particularly noteworthy that the probiotic combination of Lactococcus lactis IMAU11823 and Bifidobacterium animalis subspecies Cai-4 performed best in the comprehensive evaluation. This combination not only has significant advantages in improving the quality of fermented milk, but also shows simplicity and high efficiency in the preparation process.

[0023] By adopting the technical solution of the present application, the processing of probiotic fermented milk becomes more concise while maintaining a highly efficient preparation process. This not only provides an effective method for producing high-quality fermented milk products, but also lays a solid foundation for the commercial production and market promotion of probiotic fermented milk. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is the change of microrheological properties of fermented milk during the fermentation process. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail with reference to examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present application.

[0027] Basic starter culture: PSY-010, a basic starter culture produced by Ketuo Biotechnology (consisting of Lactobacillus bulgaricus and Streptococcus thermophilus, with a live cell count of 100 billion).

[0028] Auxiliary fermentation agent: Lactococcus lactis IMAU11823 (deposited in China General Microbiological Culture Collection Center, with the deposit number of CGMCC 16243); Lactococcus lactis BL-19 (deposited in China General Microbiological Culture Collection Center, with the collection number CGMCC 16242).

[0029] Active probiotics: Bifidobacterium animalis subspecies Cai-4 (deposited in the China General Microbiological Culture Collection Center, with the collection number CGMCC No.31691). Example

[0030] A method for preparing bifidobacterium fermented milk with good microrheological properties, comprising the following steps: 1. Acceptance of raw milk (qualified according to GB19301-2010); 2. Remove impurities: place the raw milk in a milk purifier to remove impurities until the impurity level is ≤ 2 ppm, and obtain fresh milk; 3. Refrigerate: Refrigerate the fresh milk in a 4°C constant temperature box and stir it continuously using a stirring device during refrigeration; 4. Homogenize by using a high-pressure homogenizer (homogenizing pressure 12-18 MPa, homogenizing for 5-8 min) to obtain homogenized milk; 5. Sterilization: sterilize the homogenized milk; 6. Fermentation with starter culture: add different probiotic starter cultures to the sterilized homogenized milk (see Table 1 below for the amount of bacteria added in different groups), and ferment the homogenized sterilized milk at 42°C for 7 hours; 7. Packaging: In a sterile environment, vacuum fill with inert gas and pack the fermented milk into bags. Use ozone sterilization for 1 hour before and after each packaging process. 8. Refrigerate: Refrigerate the packaged fermented milk products at 4°C.

[0031] Table 1 The amount of bacteria added in different groups ; Evaluation of microrheological properties of fermented milk: Pour 20 mL of milk into a special flat-bottomed cylindrical glass bottle with a stopper (inner diameter 27.5 mm), quickly transfer it to the measuring tank, set the main device of the rheometer to 37 °C, collect data once every 1 min, and when the pH value of the fermented milk is close to 4.50, immediately take out the glass bottle and refrigerate it at 4 °C for 24 h, then restore the sample to room temperature (25 °C), stir it and put it into the measuring tank to continue collecting data.

[0032] Changes in the microrheological properties of each group of fermented milk during the fermentation process Figure 1 As shown, the results showed that the rheological indicators of fermented milk of all combinations reached stability at the 4th hour during the fermentation period, and there were significant differences between the groups. The elasticity factor index, macroscopic viscosity index, solid-liquid equilibrium value and flow factor of group B, i.e. the fermentation combination of Lactococcus lactis IMAU11823 and Bifidobacterium animalis subspecies Cai-4, were improved, which was better than other combinations. Among them, group A, i.e. the fermentation combination of Bifidobacterium animalis subspecies Cai-4 alone and the basic starter, had the lowest microrheological properties. The scores between groups B and C were also significantly different, and the score of combination B was significantly higher than that of combination C ( P <0.05), indicating that Bifidobacterium animalis subsp. lactis Cai-4 can produce a synergistic effect with Lactococcus lactis IMAU11823.

[0033] In summary, compared with other groups, the combined use of Lactococcus lactis IMAU11823 and Bifidobacterium animalis subspecies Cai-4 can make the fermented milk have good microrheological properties and is the best in all aspects. Example

[0034] A method for preparing bifidobacterium fermented milk with good microrheological properties, comprising the following steps: 1. Acceptance of raw milk (qualified according to GB19301-2010); 2. Remove impurities: place the raw milk in a milk purifier to remove impurities until the impurity level is ≤ 2 ppm, and obtain fresh milk; 3. Refrigerate: Refrigerate the fresh milk in a 4°C constant temperature box and stir it continuously using a stirring device during refrigeration; 4. Homogenize by using a high-pressure homogenizer (homogenizing pressure 12-18 MPa, homogenizing for 5-8 min) to obtain homogenized milk; 5. Sterilization: sterilize the homogenized milk; 6. Fermentation with starter culture: add 0.03‰ basic starter culture PSY-010 and 1.0×10 7 (CFU / mL) Lactococcus lactis IMAU11823 and 2.0×10 7 (CFU / mL) Probiotic starter culture of Bifidobacterium animalis subsp. lactis Cai-4 was fermented on homogenized sterilized bovine milk at 42 °C for 7 h; 7. Packaging: In a sterile environment, vacuum fill with inert gas and pack the fermented milk into bags. Use ozone sterilization for 1 hour before and after each packaging process. 8. Refrigerate: Refrigerate the packaged fermented milk products at 4°C.

[0035] The obtained fermented milk had no significant difference from that in Example 1 in terms of microrheological property index evaluation. Example

[0036] A method for preparing bifidobacterium fermented milk with good microrheological properties, comprising the following steps: 1. Acceptance of raw milk (qualified according to GB19301-2010); 2. Remove impurities: place the raw milk in a milk purifier to remove impurities until the impurity level is ≤ 2 ppm, and obtain fresh milk; 3. Refrigerate: Refrigerate the fresh milk in a 4°C constant temperature box and stir it continuously using a stirring device during refrigeration; 4. Homogenize by using a high-pressure homogenizer (homogenizing pressure 12-18 MPa, homogenizing for 5-8 min) to obtain homogenized milk; 5. Sterilization: sterilize the homogenized milk; 6. Fermentation with starter culture: add 0.03‰ basic starter culture PSY-010, 2.0×10 7 (CFU / mL) Lactococcus lactis IMAU11823 and 1.0×10 7 (CFU / mL) Probiotic starter culture of Bifidobacterium animalis subsp. lactis Cai-4 was fermented on homogenized sterilized bovine milk at 42 °C for 7 h; 7. Packaging: In a sterile environment, vacuum fill with inert gas and pack the fermented milk into bags. Use ozone sterilization for 1 hour before and after each packaging process. 8. Refrigerate: Refrigerate the packaged fermented milk products at 4°C.

[0037] The obtained fermented milk had no significant difference from that of Example 1 in terms of microrheological properties evaluation. Example

[0038] A method for preparing bifidobacterium fermented milk with good microrheological properties, comprising the following steps: 1. Acceptance of raw milk (qualified according to GB19301-2010); 2. Remove impurities: place the raw milk in a milk purifier to remove impurities until the impurity level is ≤ 2 ppm, and obtain fresh milk; 3. Refrigerate: Refrigerate the fresh milk in a 4°C constant temperature box and stir it continuously using a stirring device during refrigeration; 4. Homogenize by using a high-pressure homogenizer (homogenizing pressure 12-18 MPa, homogenizing for 5-8 min) to obtain homogenized milk; 5. Sterilization: sterilize the homogenized milk; 6. Fermentation with starter culture: add 0.03‰ basic starter culture PSY-010, 2.0×10 7 (CFU / mL) Lactococcus lactis IMAU11823 and 3.0×10 7 (CFU / mL) Probiotic starter culture of Bifidobacterium animalis subspecies Cai-4 was fermented on homogenized sterilized bovine milk at 42 °C for 7 h; 7. Packaging: In a sterile environment, vacuum fill with inert gas and pack the fermented milk into bags. Use ozone sterilization for 1 hour before and after each packaging process. 8. Refrigerate: Refrigerate the packaged fermented milk products at 4°C.

[0039] The obtained fermented milk had no significant difference from that of Example 1 in terms of microrheological properties evaluation.

[0040] The above description is only a preferred example of the present application and does not limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A probiotic fermentation agent, characterized in that: The probiotic fermentation agent comprises a basic fermentation agent, an auxiliary fermentation agent and active probiotics, wherein the basic fermentation agent contains Lactobacillus bulgaricus and Streptococcus thermophilus, the auxiliary fermentation agent contains Lactococcus lactis IMAU11823, and the active probiotics contain Bifidobacterium animalis subspecies Cai-4; the Lactococcus lactis IMAU11823 is preserved in the General Microbiological Culture Collection Center of the China Microorganism Culture Collection Administration, with a preservation number of CGMCC 16243; the Bifidobacterium animalis subspecies Cai-4 is preserved in the General Microbiological Culture Collection Center of the China Microorganism Culture Collection Administration, with a preservation number of CGMCC No.31691.

2. The probiotic fermentation agent according to claim 1, characterized in that The ratio of the live bacteria count of Lactococcus lactis IMAU11823 and Bifidobacterium animalis subspecies lactis Cai-49 is 1:100-100:

1.

3. A fermented milk, characterized in that: The probiotic fermentation agent as claimed in claim 1 is added to animal milk for fermentation.

4. The fermented milk according to claim 3, characterized in that The amount of auxiliary fermentation agent and active probiotics added was 1.0×10 5 -1.0×10 12 CFU / mL.

5. A method for preparing the fermented milk according to claim 3, characterized in that: The method comprises the following steps: adding the probiotic fermentation agent as claimed in claim 1 to animal milk for fermentation.

6. The preparation method according to claim 4, characterized in that: The addition amount of the basic leavening agent is 0.01‰-0.05‰ (weight percentage).

7. The preparation method according to claim 4, characterized in that: The fermentation time is 5-10h.

8. Use of the probiotic starter according to claim 1 in preparing fermented milk.

9. Use of the probiotic starter according to claim 8 for preparing fermented milk, characterized in that: The invention discloses a probiotic fermentation agent for preparing milk fermented milk.

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