A fermented milk made from Bifidobacterium animalis and its preparation method

Abstract

This invention relates to the field of dairy products, and in particular to a fermented milk made with Bifidobacterium animalis and its preparation method. The invention provides a method for preparing fermented milk made with Bifidobacterium animalis, comprising: providing a Bifidobacterium animalis growth promoter, wherein the growth promoter comprises a slurry of cooked red beans and pineapple pulp; mixing the Bifidobacterium animalis growth promoter with milk to provide a fermentation system; inoculating the fermentation system with Bifidobacterium animalis; and fermenting. The method for preparing fermented milk made with Bifidobacterium animalis provided by this invention, and the resulting fermented milk, have advantages over other similar products, including natural edibility, good taste, and low cost. Furthermore, it is a pure fermentation process, free from contamination by other microorganisms, and the resulting fermented milk has a long shelf life, thus effectively solving the problems existing in other similar products in the prior art, and has good industrialization prospects.

Description

Technical Field

[0001] This invention relates to the field of dairy products, and in particular to a fermented milk made with Bifidobacterium animalis and its preparation method. Background Technology

[0002] Bifidobacteria are dominant bacteria in the healthy human gut, possessing beneficial functions such as antagonizing pathogenic bacteria, regulating gut microbiota, synthesizing various vitamins, lowering cholesterol, preventing cancer, and enhancing immunity. Currently, probiotic health products containing Bifidobacteria are widely available both domestically and internationally, enjoying great popularity among consumers. However, Bifidobacteria typically struggle to grow and multiply in milk. While fermented milk products containing Bifidobacteria have been developed from various technological perspectives, some have complex compositions and high costs, some use non-natural, edible materials resulting in poor taste, some are mixed fermentations and not pure Bifidobacteria products, and some have poor viability, short shelf lives, and difficulty in marketability. Moreover, most existing fermented milk products containing Bifidobacteria neglect the detection of contamination by other bacteria, making it difficult to guarantee the true content of Bifidobacteria. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a fermented milk made from Bifidobacterium animalis and its preparation method, so as to solve the problems in the prior art.

[0004] To achieve the above and other related objectives, the present invention provides a method for preparing fermented milk containing Bifidobacterium animalis, comprising:

[0005] 1) Provide an animal bifidobacteria growth agent, said animal bifidobacteria growth agent comprising a pulp of cooked red beans and pineapple pulp;

[0006] 2) Mix the animal bifidobacteria growth promoter provided in step 1) with milk to provide a fermentation system;

[0007] 3) Inoculate the fermentation system provided in step 2) with Bifidobacterium animalis and ferment it.

[0008] In some embodiments of the present invention, the animal bifidobacteria proliferator, based on a total weight of 100 parts by weight, comprises:

[0009] 2-20 portions of red beans;

[0010] 5-30 servings of pineapple pulp.

[0011] In some embodiments of the present invention, the method for preparing the animal bifidobacteria proliferator includes: homogenizing and mixing cooked red beans and pineapple pulp; preferably, it further includes: solid-liquid separation and / or sterilization.

[0012] In some embodiments of the present invention, in step 2), the content of the animal Bifidobacterium proliferator in the fermentation system is 3-30 wt%.

[0013] In some embodiments of the present invention, in step 2), the milk is selected from one or more combinations of raw milk, liquid milk, and reconstituted milk.

[0014] In some embodiments of the present invention, in step 2), the fermentation system further includes an additive, which is selected from one or more combinations of flavoring agents, acid-base stabilizers, and thickeners.

[0015] In some embodiments of the present invention, in step 3), the animal bifidobacterium is Bifidobacterium animalis subsp. Bifidobacterium lactis.

[0016] In some embodiments of the present invention, in step 3), the inoculation concentration of Bifidobacterium animalis in the fermentation system is 0.1–200 × 10⁻⁶. 6 CFU / g.

[0017] In some embodiments of the present invention, in step 3), the fermentation temperature of the fermentation treatment is 36-38°C.

[0018] In some embodiments of the present invention, in step 3), the fermentation time of the fermentation treatment is 10 to 20 hours.

[0019] In some embodiments of the present invention, in step 3), the fermentation treatment is a static fermentation treatment.

[0020] Another aspect of the present invention provides a fermented milk containing Bifidobacterium animalis, which is prepared by the above-described method for preparing fermented milk containing Bifidobacterium animalis. Detailed Implementation

[0021] To make the inventive objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. Those skilled in the art can easily understand other advantages and effects of this invention from the content disclosed in this specification.

[0022] Through extensive practical research, the inventors of this invention discovered a Bifidobacterium animalis growth promoter and further used this promoter to prepare Bifidobacterium animalis fermented milk. The Bifidobacterium animalis fermented milk prepared using the aforementioned Bifidobacterium animalis growth promoter has advantages such as being naturally edible, having a good taste, low cost, pure fermentation, being free from contamination by other microorganisms, and having a long shelf life, thus greatly improving the product quality of Bifidobacterium animalis fermented milk. Based on this, this invention was completed.

[0023] The first aspect of this invention provides a method for preparing Bifidobacterium animalis fermented milk, comprising: 1) providing a Bifidobacterium animalis growth promoter, wherein the Bifidobacterium animalis growth promoter includes a slurry of cooked red beans and pineapple pulp; 2) mixing the Bifidobacterium animalis growth promoter provided in step 1) with milk to provide a fermentation system; 3) inoculating the fermentation system provided in step 2) with Bifidobacterium animalis and fermenting. In the preparation method provided by this application, the Bifidobacterium animalis growth promoter used may include a slurry of cooked red beans and pineapple pulp. By introducing the above-mentioned Bifidobacterium animalis growth promoter into a fermentation system including milk and inoculating it with Bifidobacterium animalis, the growth of Bifidobacterium animalis in the fermentation system can be effectively promoted during fermentation, and contamination by other bacteria (e.g., aerobic contaminants, more specifically Bacillus subtilis, Escherichia coli, Bacillus licheniformis, etc.) can be effectively avoided in the prepared Bifidobacterium animalis fermented milk.

[0024] The method for preparing fermented milk containing Bifidobacterium animalis provided by this invention may include: providing a Bifidobacterium animalis growth promoter, wherein the Bifidobacterium animalis growth promoter comprises a pulp of cooked red beans and pineapple pulp. Generally, the Bifidobacterium animalis growth promoter needs to be prepared separately and completely first, and then the prepared Bifidobacterium animalis growth promoter is mixed with milk to construct a fermentation system, thereby ensuring that the growth of Bifidobacterium animalis in the fermentation system can be effectively promoted during the fermentation process.

[0025] In the above preparation method, red beans typically refer to the mature seeds of the annual semi-twisting herbaceous plant *Vigna angularis* (legume family). When using them, they are usually first mixed with an appropriate amount of water and cooked to provide cooked red beans, which are then homogenized and mixed with other ingredients. Pineapple pulp typically refers to the pulp of the mature fruit of the monocotyledonous plant *Ananascomosus* (Linn.) Merr. (family Bromeliaceae), usually fresh pulp. The *Bifidobacterium animalis* proliferation agent, based on a total weight of 100 parts by weight, may include 2–20 parts, 2–4 parts, 4–6 parts, 6–8 parts, 8–10 parts, 10–12 parts, 12–14 parts, 14–16 parts, 16–18 parts, or 18–20 parts of red beans (dry weight, i.e., the weight of uncooked raw red beans). The total weight of the animal bifidobacteria proliferator, calculated in parts by weight, may include 5-30 parts, 5-10 parts, 10-15 parts, 15-20 parts, 20-25 parts, or 25-30 parts of pineapple pulp (by wet weight).

[0026] In the above preparation method, the Bifidobacterium animalis growth promoter may include a slurry of cooked red beans and pineapple pulp. When preparing the Bifidobacterium animalis growth promoter, the cooked red beans and pineapple pulp slurry are typically homogenized and mixed to provide the aforementioned Bifidobacterium animalis growth promoter. The Bifidobacterium animalis growth promoter may also include water, the water content of which is usually appropriate. Generally, an appropriate amount of water may be added during the process of providing cooked red beans and during the homogenization of cooked red beans and pineapple pulp to facilitate the preparation of the Bifidobacterium animalis growth promoter. For example, red beans can be mixed with an appropriate amount of water and cooked to provide cooked red beans. Another example is the formation of a slurry with an appropriate amount of water, cooked red beans, and pineapple pulp. Furthermore, the method may also include solid-liquid separation and / or sterilization, thereby removing solids from the mixture obtained by homogenization to provide a homogeneous slurry suitable for pure culture fermentation.

[0027] The method for preparing fermented milk with Bifidobacterium animalis provided by this invention may further include: mixing the Bifidobacterium animalis growth promoter provided in step 1) with milk to provide a fermentation system. The prepared Bifidobacterium animalis growth promoter can be mixed with milk and other ingredients in appropriate proportions to form a suitable fermentation system for subsequent fermentation treatment.

[0028] In the above preparation method, an appropriate amount of Bifidobacterium animalis growth promoter is usually added to the fermentation system. Generally speaking, a higher amount of Bifidobacterium animalis growth promoter can effectively increase the number of viable Bifidobacterium animalis. However, if the amount added is too high, it will affect the taste and flavor of the fermented milk. For example, the content of Bifidobacterium animalis growth promoter in the fermentation system can be 3-30 wt%, 3-4 wt%, 4-5 wt%, 5-6 wt%, 6-8 wt%, 8-10 wt%, 10-12 wt%, 12-15 wt%, 15-20 wt%, 20-25 wt%, or 25-30 wt%. The Bifidobacterium animalis growth promoter is usually uniformly mixed in the fermentation system.

[0029] In the above preparation method, the fermentation system typically needs to contain an appropriate amount of milk. The milk in the fermentation system can be raw milk or various dairy products prepared from raw milk suitable for fermentation with Bifidobacterium animalis. For example, suitable milk can be raw milk, liquid milk, reconstituted milk, etc. The milk content in the fermentation system can be appropriately adjusted by those skilled in the art; for example, the milk content in the fermentation system can be ≥5 wt%, 5–10 wt%, 10–20 wt%, 20–30 wt%, 30–40 wt%, 40–50 wt%, 50–60 wt%, 60–70 wt%, 70–80 wt%, 80–90 wt%, or higher.

[0030] In the above preparation method, the fermentation system may also contain additives. The type and amount of suitable additives for preparing fermented milk should be adjustable for those skilled in the art. For example, the additives may be selected from one or more combinations of flavoring agents (e.g., sucrose), acid-base stabilizers (e.g., sodium citrate), and thickeners (e.g., pectin, starch). For another example, the amount of flavoring agent added to the fermentation system may be 2.5–7.5 wt%, 2.5–3.5 wt%, 3.5–4.5 wt%, 4.5–5.5 wt%, 5.5–6.5 wt%, or 6.5–7.5 wt%. For yet another example, the amount of acid-base stabilizer added to the fermentation system may be 0.1–1 wt%, 0.1–0.2 wt%, 0.2–0.4 wt%, 0.4–0.6 wt%, 0.6–0.8 wt%, or 0.8–1 wt%. For example, the amount of thickener added to the fermentation system can be 0.1–1 wt%, 0.1–0.2 wt%, 0.2–0.4 wt%, 0.4–0.6 wt%, 0.6–0.8 wt%, or 0.8–1 wt%.

[0031] The method for preparing Bifidobacterium animalis fermented milk provided by the present invention may further include: inoculating the fermentation system provided in step 2) with Bifidobacterium animalis and fermenting it. After mixing the Bifidobacterium animalis growth promoter with a suitable proportion of milk and other ingredients to form a suitable fermentation system, the fermentation system can be fermented to provide the above-mentioned Bifidobacterium animalis fermented milk.

[0032] In the above preparation method, *Bifidobacterium animalis* is a type of anaerobic, Gram-positive bacillus belonging to the genus *Bifidobacterium*. In a specific embodiment of the present invention, *Bifidobacterium animalis* can be *Bifidobacterium animalis* subsp. *Lactis*, etc.

[0033] In the above preparation method, the fermentation system typically needs to be inoculated with an appropriate amount of Bifidobacterium animalis. Before inoculation, the fermentation system or its components (e.g., milk, water, etc.) can usually be sterilized to ensure pure culture fermentation. The appropriate inoculation amount should be adjustable for those skilled in the art; for example, the inoculation concentration of Bifidobacterium animalis in the fermentation system (based on the final concentration in the fermentation broth) can be 0.1-200 × 10⁻⁶. 6 CFU / g, 0.1-0.5×10 6 CFU / g, 0.5-1×10 6 CFU / g, 1-5×10 6 CFU / g, 5-10×106 CFU / g, 10-20×10 6 CFU / g, 20-40×10 6 CFU / g, 20-40×10 6 CFU / g, 40-60×10 6 CFU / g, 60-80×10 6 CFU / g, 80-100×10 6 CFU / g, 100-120×10 6 CFU / g, 120-140×10 6 CFU / g, 140-160×10 6 CFU / g, 160-180×10 6 CFU / g, or 180-200×10 6 CFU / g.

[0034] In the above preparation method, the fermentation treatment is usually a static fermentation treatment. Those skilled in the art can select appropriate fermentation conditions according to the type of microorganism. For example, the fermentation temperature can be 36–38℃, 36–36.5℃, 36.5–37℃, 37–37.5℃, or 37.5–38℃. As another example, the fermentation time can be 10–20h, 10–12h, 12–14h, 14–16h, 16–18h, or 18–20h.

[0035] The second aspect of this invention provides a fermented milk containing Bifidobacterium animalis, prepared by the method for preparing fermented milk containing Bifidobacterium animalis provided in the first aspect of this invention. The fermented milk containing Bifidobacterium animalis prepared by the above-described method is essentially free from contamination by other microorganisms (e.g., aerobic contaminants, more specifically, Bacillus subtilis, Escherichia coli, Bacillus licheniformis, etc.) and exhibits excellent microbial enrichment. For example, in an experiment to count aerobic contaminants on a culture medium (e.g., LB medium), the total number of aerobic colonies can be <1×10⁻⁶. 1 CFU / g. For example, in experiments counting Bifidobacterium animalis in fermented milk on a culture medium (e.g., TPY medium), the total number of Bifidobacterium animalis colonies can be ≥1×10⁻⁶. 8 CFU / g, ≥3×10 8 CFU / g, ≥5×10 8 CFU / g, ≥8×10 8 CFU / g, or ≥1×10 9CFU / g. Furthermore, the Bifidobacterium animalis fermented milk prepared by the above method has a longer shelf life. After one month of refrigeration (at 10°C), the viable count remains ≥30%, ≥35%, or ≥37%. In experiments counting Bifidobacterium animalis on a culture medium (e.g., TPY medium), the total number of Bifidobacterium animalis colonies remains ≥1.0 × 10⁻⁶. 8 CFU / g, or ≥3×10 8 CFU / g.

[0036] The method for preparing Bifidobacterium animalis fermented milk provided by this invention and the fermented milk obtained therefrom have advantages over other similar products, such as being naturally edible, having a good taste, and being low in cost. Moreover, it is a pure fermentation process without contamination by other bacteria, and the fermented milk obtained has a long shelf life. Thus, it effectively solves the problems existing in other similar products in the prior art and has good prospects for industrialization.

[0037] The invention of this application will be further illustrated by the following embodiments, but this does not limit the scope of this application.

[0038] Example 1

[0039] Preparation of Bifidobacterium animalis proliferation agent:

[0040] Animal Bifidobacterium proliferation agent 1: Soak 1 part by weight of red beans in water for 6 hours, add water to 9 parts by weight, cook until done (100℃ for 1-2 hours), and then cool. Add 2 parts by weight of fresh pineapple and 8 parts by weight of water, and mix well. Keep warm at 55℃ for 4 hours, filter to remove residue, and sterilize. This is used as an animal Bifidobacterium proliferation agent.

[0041] Animal Bifidobacterium proliferation agent 2: Soak 1 part by weight of red beans in water for 10 hours, add water to make up to 9 parts by weight, cook until done, and cool. Add 4 parts by weight of fresh pineapple and 6 parts by weight of water, mix well. Keep warm at 55℃ for 4 hours, filter to remove residue, and sterilize. This is used as a proliferation agent for animal bifidobacterium.

[0042] Animal Bifidobacterium proliferation agent 3: Soak 2 parts by weight of red beans in water for 16 hours, add water to make up to 8 parts by weight, cook until done, and cool. Add 5 parts by weight of fresh pineapple and 5 parts by weight of water, mix well. Keep warm at 55℃ for 4 hours, filter to remove residue, and sterilize. This is used as a proliferation agent for animal bifidobacterium.

[0043] Blank control: Soak 1 part by weight of red beans in water for 16 hours, add water to make up to 9 parts by weight, cook and cool. Add another 10 parts by weight of water, homogenize and mix well. Keep warm at 55℃ for 4 hours, filter to remove residue and sterilize, as a blank control for the proliferation of Bifidobacterium animalis.

[0044] To determine the effect of the proliferators on Bifidobacterium animalis, the prepared Bifidobacterium animalis proliferators were added to milk (fresh milk, produced by Bright Dairy & Food Co., Ltd.) at a mass ratio of 10%, sterilized at 105℃ for 10 min, and the final concentration obtained after inoculation was approximately 1.0 × 10⁻⁶. 6 CFU / g (Bifidobacterium animalis Bifidobacterium lactis subsp.) Bifidobacterium animalis subsp. lactis BB-12). Fermentation was carried out for 12 hours, followed by serial dilutions. Aerobic contaminants were counted using LB agar (after 48 hours of aerobic incubation at 37°C on LB agar), and Bifidobacteria were counted using TPY agar (after 72 hours of anaerobic incubation at 37°C on TPY agar). The results are shown in Table 1. The TPY viable count results in Table 1 show that all prepared growth promoters promoted the growth of Bifidobacterium animalis in milk. The growth promoter with added pineapple showed better growth, and the growth effect further improved with increasing pineapple content. The growth promoter without added pineapple showed relatively poor growth. The total aerobic colony count results in Table 1 show that there was virtually no contamination during the pure Bifidobacterium fermentation process, and the growth effect was reliable.

[0045] Table 1

[0046] Total aerobic bacterial count (CFU / g) TPY viable cell count (CFU / g) Production Method 1 <![CDATA[<1×10 1 ]]> <![CDATA[5.1×10 8 ]]> Production Method 2 <![CDATA[<1×10 1 ]]> <![CDATA[8.7×10 8 ]]> Production Method 3 <![CDATA[<1×10 1 ]]> <![CDATA[1.7×10 9 ]]> Blank control <![CDATA[<1×10 1 ]]> <![CDATA[1.2×10 6 ]]>

[0047] Example 2

[0048] Fermented milk made with Bifidobacterium animalis and added sodium citrate:

[0049] Animal Bifidobacterium fermented milk formula: 50 parts by weight of raw milk, 10 parts by weight of sucrose, 1 part by weight of sodium citrate, 0.2 parts by weight of thickener (pectin (Zhengzhou Tianshun, food grade)). The growth agent is prepared according to the method in Example 1 Animal Bifidobacterium growth agent 2. The amount of animal Bifidobacterium growth agent added is 5 parts by weight, 10 parts by weight, 15 parts by weight, and 20 parts by weight. The remaining amount is adjusted with water to make up to 100 parts by weight.

[0050] Preparation method: The above-mentioned mixed liquid was preheated and homogenized at 65℃ and 20MPa, then sterilized at 105℃ for 10 min, and cooled to 37℃. Animal Bifidobacterium was inoculated (strain same as in Example 1, final concentration approximately 1.0 × 10⁻⁶). 6Fermentation was carried out for 8 hours (CFU / g). Samples were serially diluted, and aerobic contaminants were counted on LB medium, while Bifidobacteria were counted on TPY medium. The results are shown in Table 2. For sensory evaluation, five professionals tasted the fermented product and provided their evaluations. If the evaluations were inconsistent, the majority opinion prevailed. The evaluation results included acidity and taste. Acidity was categorized into four levels: sweet and sour, slightly sour, quite sour, and sour. Taste was categorized into three levels: palatable, bitter, and bitter. Table 2 shows that the number of viable Bifidobacteria in animals increased with the addition of the growth promoter. When the addition was below 10%, the fermented milk was sweet and palatable, but when the addition was above 15%, the sensory characteristics leaned towards sourness and bitterness, resulting in a poor flavor. Table 2 shows that the total aerobic colony count indicated that there was virtually no contamination during the pure Bifidobacteria fermentation process, indicating pure culture fermentation.

[0051] Table 2

[0052]

[0053]

[0054] Example 3

[0055] Animal Bifidobacterium fermented milk storage survival:

[0056] Animal Bifidobacterium fermented milk was prepared using the formula in Example 2 (with a 10% growth promoter). After packaging, it was stored at 10°C for 30 days, serially diluted, and aerobic contaminants were counted using LB medium, while Bifidobacteria were counted using TPY medium. The experimental results are shown in Table 3. As can be seen from the TPY viable count results in Table 3, the viable bacterial count in the sample did not decrease significantly within the 30-day shelf life, still reaching 3.1 × 10⁻⁶. 8 The CFU / g level is far higher than the minimum limit for live lactic acid bacteria count specified in the Hygienic Standard for Lactic Acid Bacteria Beverages (GB 16321-2003): 1.0 × 10⁻⁶. 6 According to the relevant regulations regarding "CFU / g", the Bifidobacterium animalis in the sample had a high survival rate. As shown in Table 3, the total aerobic colony count results indicate that the sample remained essentially free of contamination during storage. Furthermore, the sample remained sweet and sour and remained stable after storage.

[0057] Table 3

[0058]

[0059] Example 4

[0060] Add a control experiment directly:

[0061] Method 1:

[0062] Soak 1 part red beans in water for 6 hours, then add water to bring the total weight to 9 parts. Cook until done and cool. Add 2 parts fresh pineapple and 8 parts water, then mix well. Keep warm at 50℃ for 3 hours, filter to remove residue, and sterilize. Use as a growth promoter for Bifidobacterium animalis.

[0063] Ingredients: 50 parts by weight of raw milk, 10 parts by weight of sucrose, 1 part by weight of sodium citrate, 0.1 parts by weight of thickener, 10 parts by weight of Bifidobacterium animalis growth promoter, and the remainder adjusted to 100 parts by weight with water. The mixture was preheated, homogenized at 65°C and 20 MPa, sterilized at 105°C for 10 minutes, and then cooled to 37°C. Bifidobacterium animalis was inoculated (strain same as in Example 1, final concentration approximately 3.0 × 10⁻⁶). 6 Fermentation was carried out for 12 hours (CFU / g). Samples were serially diluted, and aerobic contaminants were counted on LB medium, while Bifidobacteria were counted on TPY medium.

[0064] Method 2:

[0065] Soak 1 part by weight of red beans in water for 6 hours, then add water to make 9 parts by weight. Cook until done, then cool to make red bean milk. Ingredients: 50 parts by weight of raw milk, 10 parts by weight of sucrose, 1 part by weight of sodium citrate, 0.1 part by weight of thickener, 5 parts by weight of red bean milk, 1 part by weight of fresh pineapple, and adjust the weight with water to make 100 parts by weight. Other operations are the same as in Example 1 of this embodiment.

[0066] The experimental results are shown in Table 4. Method 1 first prepared the Bifidobacterium animalis growth agent separately and completely, and then mixed the prepared Bifidobacterium animalis growth agent with milk to construct a fermentation system, which had a better growth effect. Method 2 had the same content of each substance in the formula as Method 1, but in Method 2, red beans and pineapple were directly mixed with other components of the fermentation system, so the growth effect was not good.

[0067] Table 4

[0068]

[0069] In summary, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a fermented milk of animal bifidobacterium, comprising: 1) providing an animal bifidobacterium proliferation agent, the animal bifidobacterium proliferation agent comprising a slurry of cooked red beans and pineapple pulp, the method for preparing the animal bifidobacterium proliferation agent comprising: homogenizing and mixing the cooked red beans and the pineapple pulp, the raw materials in the animal bifidobacterium proliferation agent comprising, by weight based on 100 parts: red beans 4-12 parts; pineapple pulp 10-30 parts; 2) mixing the animal bifidobacterium proliferation agent provided in step 1) and milk to provide a fermentation system, the content of the animal bifidobacterium proliferation agent in the fermentation system being 5-10 wt%; 3) inoculating the animal bifidobacterium into the fermentation system provided in step 2) and performing fermentation treatment.

2. The method of claim 1, wherein the Bifidobacterium animalis fermentate is prepared by the method comprising: fermenting a milk by Bifidobacterium animalis; and drying the fermented milk. In the step 1), the method for preparing the animal bifidobacterium proliferation agent further comprises: solid-liquid separation and / or sterilization.

3. The method of claim 1, wherein the Bifidobacterium animalis fermentate is prepared by the method comprising: fermenting a milk by Bifidobacterium animalis; and drying the fermented milk. In the step 2), the milk is selected from the group consisting of one or more combinations of raw milk, liquid milk, and reconstituted milk.

4. The method of claim 1, wherein the Bifidobacterium animalis fermentate is prepared by the method comprising: fermenting a milk by Bifidobacterium animalis; and drying the fermented milk. In the step 2), the fermentation system further comprises an additive, the additive being selected from the group consisting of one or more combinations of flavoring agents, acid-base stabilizers, and thickening agents.

5. The preparation method of animal bifidobacterium fermented milk according to claim 1, characterized by, In the step 3), the animal bifidobacterium is animal bifidobacterium Bifidum subsp. lactis.

6. The preparation method of animal bifidobacterium fermented milk according to claim 1, characterized in that, In the step 3), the inoculation concentration of the Bifidobacterium animalis in the fermentation system is 0.1-200×10 6 CFU / g.

7. The method of claim 1, wherein the B. animalis fermented milk is prepared by fermenting milk with B. animalis under conditions of 37°C for 24 hours. In the step 3), the fermentation temperature of the fermentation treatment is 36-38℃; And / or, the fermentation time of the fermentation treatment is 10-20h; And / or, the fermentation treatment is a static fermentation treatment. 8.An animal bifidobacterium fermented milk, prepared by the method for preparing the animal bifidobacterium fermented milk according to any one of claims 1-7.

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