A processing method for clean-label high-protein buffalo fermented milk

Abstract

This invention discloses a processing method for clean-label high-protein buffalo fermented milk, belonging to the field of dairy processing technology. It aims to solve the problems of existing buffalo fermented milk relying on exogenous proteins and stabilizers, which does not conform to the clean-label trend and cannot simultaneously achieve high protein content, natural flavor, and shelf-life stability. This invention mixes fresh buffalo milk and fresh cow milk in a specific ratio, followed by physical enrichment of proteins using an ultrafiltration-nanofiltration membrane, secondary homogenization, sterilization and cooling, directional fermentation with a compound microbial strain, cooling and ripening, and aseptic filling. This invention uses no exogenous additives throughout the entire process, producing fermented milk with ≥4.0g / 100g protein, no more than 4 ingredients, a shelf life of ≥21 days at 2-6℃, whey separation rate ≤3%, and no fat floating. It solves the stability issues of systems without stabilizers and increases the added value of buffalo milk.

Description

Technical Field

[0001] This invention belongs to the technical field of dairy product processing, specifically relating to a processing method for clean-label high-protein buffalo fermented milk. Background Technology

[0002] Buffalo milk is naturally high in protein, milk fat, and total solids, with a protein content exceeding 3.8g / 100g and a milk fat percentage exceeding 6.5%. Its nutritional value is significantly superior to that of regular Holstein milk, making it a high-quality raw material for producing premium fermented milk. However, existing buffalo fermented milk processing technology suffers from the following core defects: 1. High-protein products generally rely on exogenous whey protein powder, sodium caseinate and other additives to increase protein content. The ingredients are complex, which does not conform to the trend of clean label consumption and can also easily lead to a bitter taste and uncoordinated flavor. 2. To address issues such as whey separation, fat floating, and texture collapse, commercially available products generally add stabilizers such as pectin, gelatin, and modified starch, which violates the minimalist ingredient concept and masks the natural flavor of buffalo milk. 3. Existing processes are not specifically optimized for the nutritional characteristics of buffalo milk and mostly use ordinary cow milk fermentation processes, which cannot simultaneously ensure no exogenous additives, high protein levels, and shelf-life stability. As a result, products are highly homogenized and the added value of buffalo milk is not fully realized. 4. Existing membrane filtration protein enrichment processes are mostly adapted to regular cow's milk and have not been optimized for the high-fat characteristics of buffalo milk. This can easily lead to problems such as membrane fouling, low enrichment efficiency, and instability of the subsequent fermentation system. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a processing method for clean-label high-protein buffalo fermented milk that solves the problems of fat floating, whey separation, and poor shelf-life stability in fermented milk without stabilizers.

[0004] This invention is achieved through the following technical solution: A method for processing clean-label high-protein buffalo fermented milk includes the following steps: (1) Raw material standardization: Fresh buffalo milk and fresh cow milk are mixed in a weight ratio of 50~70:30~50 to obtain mixed raw milk; the fresh buffalo milk has a milk protein ≥3.8g / 100g and a milk fat ≥6.5g / 100g; the fresh cow milk has a milk protein ≥3.2g / 100g. (2) Membrane filtration physical enrichment: The mixed raw milk is preheated to 45~55℃ and concentrated using an ultrafiltration-nanofiltration combined membrane system. The operating pressure is 0.6~1.2MPa, the membrane molecular weight cutoff is 8000~10000Da, and the milk protein content is concentrated to 4.2~4.8g / 100g to obtain enriched milk base; (3) Secondary homogenization: The enriched emulsion base is preheated to 60~65℃ and a two-stage homogenization process is adopted, with a total homogenization pressure of 15~20MPa. (4) Sterilization and cooling: The homogenized milk base is sterilized at 90~95℃ for 300~360s, and then rapidly cooled to 42~43℃ to obtain the milk base to be fermented. (5) Directional fermentation: Inoculate the milk base to be fermented with a compound fermentation strain of 0.01% to 0.03% of the total mass of the milk base to be fermented, and ferment at a constant temperature of 42 to 43°C until the pH of the system is 4.3 to 4.5, and then terminate the fermentation; the compound fermentation strain is a compound of Streptococcus thermophilus, Lactobacillus bulgaricus and Lactobacillus plantarum, with a live bacteria ratio of 2:1:1; the total live bacteria count of the compound strain is 1×10¹¹ CFU / g.

[0005] (6) Cooling and ripening: The fermented material is rapidly cooled to 2~6℃ and then refrigerated for 12~24h. (7) Aseptic filling, cold chain storage at 2~6℃.

[0006] Further, in step (1), the weight ratio of the raw buffalo milk to the raw cow milk is (60~65):(35~40).

[0007] Further, in step (2), the concentration and enrichment temperature is 48~52℃, the operating pressure is 0.8~1.0MPa, and the concentration is carried out until the milk protein content reaches 4.4~4.6g / 100g.

[0008] Furthermore, in step (3), the primary homogenization pressure of the secondary homogenization process is 12~15MPa, and the secondary homogenization pressure is 3~5MPa.

[0009] Furthermore, in step (4), the sterilization temperature is 92~94℃ and the heat preservation time is 320~340s.

[0010] Further, in step (5), the inoculation amount of the compound fermentation strain is 0.015% to 0.025% of the compound fermentation strain.

[0011] Furthermore, in step (6), the post-ripening time is 16~20h.

[0012] Furthermore, the fermented milk is prepared using the processing method described in any one of claims 1 to 7, wherein the protein content is ≥4.0g / 100g, the ingredients list contains no more than 4 kinds of ingredients, and it does not contain exogenous proteins, stabilizers, or thickeners.

[0013] Furthermore, the fermented milk has a shelf life of ≥21 days at 2~6℃, with a whey separation rate of ≤3% during the shelf life and no visible fat floating on the surface.

[0014] The beneficial effects of this invention are: This invention does not add any exogenous protein, stabilizers, or thickeners throughout the entire process, achieving a finished product protein content of ≥4.0g / 100g and ≤4 ingredients. It solves the problems of fat floating, whey separation, and poor shelf-life stability in fermented milk without stabilizers, thus significantly enhancing the added value of milk from our own buffalo ranch. Detailed Implementation

[0015] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0016] The terms “comprising,” “including,” or any other variations thereof in the description of this invention are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Example 1

[0017] 1. Raw material standardization: 65 parts of fresh buffalo milk and 35 parts of fresh cow milk from the farm were mixed. The fresh buffalo milk had a milk protein content of 3.9g / 100g and a milk fat content of 7.2g / 100g, while the fresh cow milk had a milk protein content of 3.3g / 100g. The mixture passed the test. 2. Membrane filtration enrichment: The mixed milk is preheated to 50°C, and an ultrafiltration-nanofiltration combined membrane system is used with an operating pressure of 0.9 MPa and a molecular weight cutoff of 10,000 Da to concentrate the milk to a protein content of 4.5 g / 100 g, thus obtaining enriched milk base; 3. Secondary homogenization: The enriched emulsion base is preheated to 62°C, the primary homogenization pressure is 14 MPa, the secondary homogenization pressure is 4 MPa, and the total homogenization pressure is 18 MPa; 4. Sterilization and cooling: Sterilize at 93℃ for 330 seconds, then quickly cool to 43℃. 5. Directional fermentation: Inoculate with 0.02 parts by weight of a compound microbial strain (Streptococcus thermophilus: Lactobacillus bulgaricus: Lactobacillus plantarum = 2:1:1), ferment at a constant temperature of 43℃ until pH = 4.4, then terminate fermentation; the total viable count of the compound microbial strain is 1×10¹¹ CFU / g.

[0018] 6. Cooling and ripening: Quickly cool to 4℃ and refrigerate for 18 hours for post-ripening; 7. Aseptic filling, cold chain storage at 4℃.

[0019] Finished product test results: protein content 4.3g / 100g, only 3 ingredients; after storage at 2~6℃ for 21 days, no visible fat separation was observed, whey separation rate was 2.1%, and microbiological indicators were qualified. Example 2

[0020] 1. Raw material standardization: 60 parts of fresh buffalo milk and 40 parts of fresh cow milk from the farm were mixed. The fresh buffalo milk had 3.8g / 100g of milk protein and 6.8g / 100g of milk fat, while the fresh cow milk had 3.2g / 100g of milk protein. The mixture was tested and found to be qualified. 2. Membrane filtration enrichment: The mixed milk is preheated to 48°C, the operating pressure is 1.0 MPa, the molecular weight cutoff is 9000 Da, and the milk protein content is concentrated to 4.4 g / 100 g; 3. Secondary homogenization: Preheat to 60℃, primary homogenization pressure 13MPa, secondary homogenization pressure 3MPa, total homogenization pressure 16MPa; 4. Sterilization and cooling: Sterilize at 95℃ for 300 seconds, then cool to 42℃; 5. Directional fermentation: Inoculate with 0.015 parts by weight of compound microbial culture, ferment at 42℃ until pH=4.35, then terminate fermentation; the total viable count of compound microbial culture is 1×10¹¹ CFU / g.

[0021] 6. Post-cooking after cooling: refrigerate at 4℃ for 20 hours; 7. Aseptic filling and cold chain storage.

[0022] Finished product test results: protein content 4.2g / 100g, only 3 ingredients; stored at 2~6℃ for 21 days, no fat floated, whey separation rate 2.4%, and microbiological indicators were qualified. Example 3

[0023] 1. Raw material standardization: 70 parts of fresh buffalo milk and 30 parts of fresh cow milk from the farm were mixed. The fresh buffalo milk had 4.0g / 100g of milk protein and 7.5g / 100g of milk fat, while the fresh cow milk had 3.3g / 100g of milk protein. The mixture was tested and found to be qualified. 2. Membrane filtration enrichment: Preheat to 52℃, operating pressure 0.8MPa, molecular weight cutoff 10000Da, concentrate to a milk protein content of 4.6g / 100g; 3. Secondary homogenization: Preheat to 65℃, primary homogenization pressure 15MPa, secondary homogenization pressure 5MPa, total homogenization pressure 20MPa; 4. Sterilization and cooling: Sterilize at 90℃ for 360 seconds, then cool to 43℃; 5. Directional fermentation: Inoculate with 0.025 parts by weight of compound microbial culture, ferment at 43℃ until pH=4.45, then terminate fermentation; the total viable count of compound microbial culture is 1×10¹¹ CFU / g.

[0024] 6. Post-cooking after cooling: refrigerate at 4℃ for 16 hours for post-cooking; 7. Aseptic filling and cold chain storage.

[0025] Finished product test results: protein content 4.4g / 100g, only 3 ingredients; stored at 2~6℃ for 21 days, no fat floated, whey separation rate 1.8%, and microbiological indicators were qualified.

[0026] Comparative example (conventional process) Using commercially available standard yogurt production process: 30 parts raw buffalo milk and 70 parts raw cow milk, whey protein powder added to achieve a protein content of 4.0g / 100g, pectin and gelatin stabilizers added, sterilized at 95℃ for 300s, inoculated with common commercial yogurt starter cultures (Streptococcus thermophilus + Lactobacillus bulgaricus 1:1), fermented at 42℃ to pH=4.5, cooled and ripened for 12 hours before packaging.

[0027] The comparison results between the examples and the comparative examples are shown in Table 1:

[0028] Table 1 In summary, the processing method of this invention achieves clean labeling, high protein content, excellent shelf-life stability, and good sensory quality without relying on the addition of exogenous excipients, thus fully achieving the purpose of the invention. Compared with conventional buffalo fermented milk processing technology, it has significant technical advantages and industrial application value.

[0029] The scope of protection of this invention is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this invention shall fall within the scope of protection of this invention.

Claims

1. A processing method for clean-label high-protein buffalo fermented milk, characterized in that: Includes the following steps: (1) Raw material standardization: Fresh buffalo milk and fresh cow milk are mixed in a weight ratio of 50~70:30~50 to obtain mixed raw milk; the fresh buffalo milk has a milk protein ≥3.8g / 100g and a milk fat ≥6.5g / 100g; the fresh cow milk has a milk protein ≥3.2g / 100g. (2) Membrane filtration physical enrichment: The mixed raw milk is preheated to 45~55℃ and concentrated using an ultrafiltration-nanofiltration combined membrane system. The operating pressure is 0.6~1.2MPa, the membrane molecular weight cutoff is 8000~10000Da, and the milk protein content is concentrated to 4.2~4.8g / 100g to obtain enriched milk base; (3) Secondary homogenization: The enriched emulsion base is preheated to 60~65℃ and a two-stage homogenization process is adopted, with a total homogenization pressure of 15~20MPa. (4) Sterilization and cooling: The homogenized milk base is sterilized at 90~95℃ for 300~360s, and then rapidly cooled to 42~43℃ to obtain the milk base to be fermented. (5) Directional fermentation: Inoculate the milk base to be fermented with a compound fermentation strain of 0.01% to 0.03% of the total mass of the milk base to be fermented, and ferment at a constant temperature of 42 to 43°C until the pH of the system is 4.3 to 4.5, and then terminate the fermentation; the compound fermentation strain is a compound of Streptococcus thermophilus, Lactobacillus bulgaricus and Lactobacillus plantarum, with a live bacteria ratio of 2:1:1; (6) Cooling and ripening: The fermented material is rapidly cooled to 2~6℃ and then refrigerated for 12~24h. (7) Aseptic filling, cold chain storage at 2~6℃.

2. The processing method according to claim 1, characterized in that: In step (1), the weight ratio of fresh buffalo milk to fresh cow milk is (60~65):(35~40).

3. The processing method according to claim 1, characterized in that: In step (2), the concentration and enrichment temperature is 48~52℃, the operating pressure is 0.8~1.0MPa, and the concentration is carried out until the milk protein content reaches 4.4~4.6g / 100g.

4. The processing method according to claim 1, characterized in that: In step (3), the primary homogenization pressure of the secondary homogenization process is 12~15MPa, and the secondary homogenization pressure is 3~5MPa.

5. The processing method according to claim 1, characterized in that: In step (4), the sterilization temperature is 92~94℃ and the heat preservation time is 320~340s.

6. The processing method according to claim 1, characterized in that: In step (5), the inoculation amount of the compound fermentation strain is 0.015% to 0.025% of the compound fermentation strain.

7. The processing method according to claim 1, characterized in that: In step (6), the post-ripening time is 16~20h.

8. A clean-label high-protein buffalo fermented milk, characterized in that: The fermented milk is prepared by any one of the processing methods described in claims 1 to 7, wherein the protein content is ≥4.0g / 100g, the ingredients list contains no more than 4 kinds of ingredients, and it does not contain exogenous protein, stabilizer or thickener.

9. The clean label high-protein buffalo fermented milk according to claim 8, characterized in that: The fermented milk has a shelf life of ≥21 days at 2~6℃, with a whey separation rate of ≤3% during the shelf life and no visible fat floating.

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