Millet enzymolysis powder fermented milk and preparation method thereof

Abstract

The invention discloses millet enzymolysis powder fermented milk and a preparation method thereof, and belongs to the technical field of food processing. Comprising the following steps: mixing millet enzymolysis powder with cow milk, sequentially carrying out colloid milling, homogenization and sterilization, inoculating a composite leavening agent for fermentation, and carrying out after-ripening after the fermentation is completed, so as to obtain the millet enzymolysis powder fermented milk. Starch in millet is directionally hydrolyzed through the combination of amylase, cellulase and protease to achieve the effect of enriching protein, the flavor of fermented milk is further improved in combination with lactobacillus fermentation, the millet enzymolysis powder fermented dairy product which is fine and smooth in taste and rich in nutrition is finally obtained, and a new thought is provided for development of fermented food.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a fermented milk made from millet enzymatic hydrolysate and its preparation method. Background Technology

[0002] Millet, a traditional grain with a long history, is rich in nutrients such as protein, starch, cellulose, and dietary fiber. It possesses various bioactivities, including lowering blood sugar and cholesterol, anti-ulcer properties, antibacterial effects, anti-inflammatory properties, and laxative effects, effectively meeting the dual needs of modern consumers for nutrition and health. Currently, millet has been processed into various food forms, such as millet porridge, millet rice crackers, and millet milk, broadening its consumption scenarios. However, millet has a relatively low protein content (usually 10%) and a complex structure, generally exhibiting low solubility and poor functional properties, which limits its widespread application in fermented dairy products.

[0003] The compound enzymatic hydrolysis technology utilizes the high specificity and selectivity of enzyme reactions and selects appropriate enzyme combinations for synergistic hydrolysis. This can effectively destroy the structure of plant cell walls, promote the dissolution of intracellular nutrients, and thus significantly increase the content of active ingredients in the solvent.

[0004] With the increasing demand for healthy foods, plant-based beverages and plant-based fermented milk have gained widespread attention due to their rich nutrition and easy digestibility. However, the protein content and quality of different plant-based ingredients vary significantly. For example, soy-based beverages have a high protein content, comparable to milk (approximately 3.0-3.5%), while beverages made from grains such as millet generally have a low protein content (usually below 1%), resulting in limited nutritional value and failing to meet consumers' needs for high-quality protein. To compensate for the shortcomings of single plant proteins in terms of nutrition and functional properties, combining millet and other grain ingredients with milk has become an effective improvement strategy. Milk, as a source of high-quality protein, is not only rich in the full spectrum of amino acids required by the human body but can also significantly increase the protein content and nutritional value of the compound system. In addition, the milk proteins in milk have good emulsifying and gelling properties, which can effectively improve the thin texture and poor stability often found in plant-based beverages, giving the product a richer, smoother milky taste.

[0005] Milk fermentation technology is a key process that uses lactic acid bacteria to convert lactose into lactic acid, thereby coagulating proteins to form yogurt. This technology not only extends the shelf life of dairy products and improves digestibility and absorption, but also imparts a unique tangy flavor and rich texture to the product through fermentation, ultimately achieving a dual enhancement of nutrition and flavor.

[0006] Current research has attempted to improve the functional properties of plant proteins through enzymatic hydrolysis or fermentation techniques. However, relying solely on a single technology to prepare fermented milk from whole grains still suffers from problems such as long production cycles, low efficiency, and unsatisfactory product flavor, affecting the quality and acceptance of the final product. Furthermore, existing processes do not adequately integrate the deep enrichment of millet protein with flavor regulation, often resulting in a rough texture or unbalanced flavor. Therefore, developing a highly efficient and synergistic combined enzymatic hydrolysis-fermentation technology using this plant-animal dual-protein synergistic strategy to achieve efficient conversion of millet protein to casein and comprehensive optimization of product flavor has significant scientific research value and broad application prospects. Such protein beverages align with modern consumers' pursuit of healthy diets. Summary of the Invention

[0007] The purpose of this invention is to provide a millet enzymatic hydrolysate fermented milk and its preparation method, thereby solving the problems existing in the prior art. The method involved in this invention, based on the traditional yogurt fermentation process, utilizes a combined enzymatic hydrolysis-fermentation technology to enrich the protein content of plant-based fermented milk and improve its flavor.

[0008] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of this invention is a method for preparing fermented milk from millet enzymatic hydrolysate, comprising the following steps: After mixing millet hydrolysate with milk, the mixture is successively subjected to gel milling, homogenization, and sterilization. Then, it is inoculated with a compound fermentation agent for fermentation. After fermentation, it undergoes post-fermentation to produce the millet hydrolysate fermented milk.

[0009] The second technical solution of the present invention is a fermented milk made from millet enzymatic hydrolysate prepared by the preparation method.

[0010] Based on the above technical solution, the present invention has the following technical effects: 1. This invention involves enzymatic hydrolysis of millet. The resulting millet powder is mixed with milk, enzymatically hydrolyzed, and fermented. The resulting product has a good texture, a smooth and delicate taste, and a unique millet flavor.

[0011] 2. By employing this plant-animal dual-protein synergistic strategy, a highly efficient and synergistic combined enzymatic hydrolysis-fermentation technology was developed to achieve efficient conversion of millet protein to casein and comprehensive optimization of product flavor. This has significant scientific research value and broad application prospects. Such protein beverages align with modern consumers' pursuit of healthy diets. 3. The preparation method of the present invention has low equipment requirements, is highly operable, consumes little energy, and has a high raw material utilization rate, making it suitable for large-scale industrial production. Detailed Implementation

[0012] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0013] This invention provides a method for preparing fermented milk from millet enzymatic hydrolysate, comprising the following steps: After mixing millet hydrolysate with milk, the mixture is successively subjected to gel milling, homogenization, and sterilization. Then, it is inoculated with a compound fermentation agent for fermentation. After fermentation, it undergoes post-fermentation to produce the millet hydrolysate fermented milk.

[0014] In some specific implementations, the ratio of the millet enzymatic hydrolysate to milk is 6g:100mL.

[0015] In some specific implementations, the conditions for the gel milling are as follows: a two-stage continuous gel milling process is adopted, with the first stage of gel milling lasting 10 minutes and the second stage lasting 8 minutes.

[0016] In some specific implementations, the homogenization conditions are: first, low pressure treatment at 30 MPa for 2 minutes, followed by high pressure treatment at 60 MPa for 2 minutes.

[0017] In some specific implementations, the sterilization temperature is 121 °C and the time is 8 s.

[0018] In some specific implementation schemes, the compound fermentation agent is purchased from Beijing Shengmu Catering Management Co., Ltd.

[0019] In some specific implementations, the fermentation conditions are as follows: 1 mg of compound fermenting agent is added per 100 mL of milk, the fermentation temperature is 42°C, and the fermentation time is 7-9 hours.

[0020] In some specific implementations, the post-ripening conditions are: refrigeration at 4 ℃ for 8-10 hours.

[0021] This invention also provides a millet enzymatic hydrolysate fermented milk prepared by the aforementioned preparation method.

[0022] The preparation method of this millet enzymatic hydrolysate fermented milk includes the following steps: sieving the millet enzymatic hydrolysate; mixing the millet enzymatic hydrolysate with milk; milling, homogenizing, sterilizing, fermenting with mixed cultures, and refrigerating for post-fermentation to obtain the millet enzymatic hydrolysate fermented milk. This invention utilizes a combination of amylase, cellulase, and protease to directionally hydrolyze starch in millet to enrich protein, and combines this with lactic acid bacteria fermentation to further improve the flavor of the fermented milk, ultimately obtaining a millet enzymatic hydrolysate fermented dairy product with a delicate texture and rich nutrition, providing a new approach for the development of fermented foods.

[0023] This invention, based on the compositional characteristics of non-protein components in grains, selects millet hydrolysate treated with a compound enzyme as the main raw material to prepare fermented milk from millet hydrolysate. The starch, cellulose, and other components of this hydrolysate have been hydrolyzed by enzymes such as amylase and cellulase, promoting the release and enrichment of proteins in the fermented milk.

[0024] The compound strains used in this invention include Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, and Lactobacillus plantarum. These strains work synergistically to promote the coagulation of milk proteins, ferment lactose to give yogurt a unique flavor, regulate intestinal flora, and enhance the body's immunity.

[0025] In this embodiment of the invention, the millet hydrolysate was purchased from Shanghai Shouye Biotechnology Co., Ltd.; the yogurt starter, comprising maltodextrin, Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, and Lactobacillus plantarum, was purchased from Beijing Shengmu Catering Management Co., Ltd.

[0026] Example 1 (1) After sieving the millet hydrolysate, mix it with milk, wherein the mass of the millet hydrolysate accounts for 6% of the volume of milk (6g:100mL).

[0027] (2) Pour the mixture into the gel mill and use a two-stage continuous gel milling process (first stage 10 min + second stage 8 min). This invention does not impose special restrictions on the conditions (such as medium, speed, temperature, etc.) of the two-stage continuous gel milling process. The conditions commonly used by those skilled in the art can be used.

[0028] (3) Homogenize the material after the rubber milling. The average parameters are: first, treat with low pressure of 30 MPa for 2 min, and then treat with high pressure of 60 MPa for 2 min.

[0029] (4) The homogenized sample was subjected to high-temperature instantaneous sterilization. The sterilization parameters were: sterilization temperature 121 ℃ and sterilization time 8 s.

[0030] (5) Ferment the sterilized sample, wherein the amount of compound fermenting agent is: 1 mg of compound fermenting agent is added for every 100 mL of milk; the fermentation temperature is 42℃ and the time is 5 h.

[0031] (6) Place the fermented sample in a 4 ℃ refrigerator for 8 h to ripen.

[0032] (7) Based on the above steps, millet enzymatic hydrolysate fermented milk is prepared.

[0033] Example 2 The only difference from Example 1 is that the fermentation time of the millet enzymatic hydrolysate fermented milk is 6 hours; all other steps and parameters are the same as in Example 1.

[0034] Example 3 The only difference from Example 1 is that the fermentation time of the millet enzymatic hydrolysate fermented milk is 7 hours; all other steps and parameters are the same as in Example 1.

[0035] Example 4 The only difference from Example 1 is that the fermentation time of the millet enzymatic hydrolysate fermented milk is 8 hours; all other steps and parameters are the same as in Example 1.

[0036] Example 5 The only difference from Example 1 is that the fermentation time of the millet enzymatic hydrolysate fermented milk is 9 hours; all other steps and parameters are the same as in Example 1.

[0037] Effect verification: The difference between Examples 1-5 lies in the fermentation time. The pH and acidity of the millet enzymatic hydrolysate fermented milk prepared in Examples 1-5 were measured. In fermented milk, pH and acidity are indicators of the degree to which lactose is fermented by lactic acid bacteria. GB19302—2010, "National Food Safety Standard for Fermented Milk," clearly stipulates that the titratable acidity of fermented milk must not be lower than 70. Table 1 shows the pH and acidity test results of the millet enzymatic hydrolysate fermented milk at different fermentation times in Examples 1-5. The acidity of the millet enzymatic hydrolysate fermented milk after 7-9 hours of fermentation can reach above 70, which meets the national standard.

[0038] Table 1. Effects of different fermentation times on pH and acidity of fermented milk made from millet enzymatic hydrolysate.

[0039] The above experiments demonstrate that the millet enzymatic hydrolysate fermented milk prepared using the method described in this invention has a uniform color, stable texture, delicate and smooth taste, and a rich aroma of millet and milk, without any unpleasant odors such as rancidity from fat oxidation, making it worthy of promotion.

[0040] Industrialization Implementation Instructions: 1. Industrialization process optimization To meet the demands of continuous industrial production, core processes are adapted and optimized. Gel mill: It adopts a two-stage continuous gel milling process (10 min for the first stage + 8 min for the second stage), which is compatible with industrial-grade continuous feeding equipment to ensure material uniformity and avoid local agglomeration; Homogenization: A continuous high-pressure homogenizer is used, and an online pressure stabilization control system is used to ensure consistent homogenization effect in large-scale production and reduce product texture differences. Sterilization: UHT continuous instantaneous sterilization unit is adopted, with a processing capacity of up to 15,000 L / h, which meets the needs of mass production efficiency. At the same time, the sterilization parameters of 121℃×8s are precisely controlled to ensure product safety and retain nutrients. Fermentation: A fully automated fermenter (with online pH and acidity monitoring modules) is used. The starter culture is added online after aseptic dilution, avoiding contamination from manual operation and enabling real-time control of fermentation process parameters. Post-ripening: Intelligent layered cold storage is used, and the temperature uniformity is controlled within ±0.5℃ to ensure consistent post-ripening effect for batches of products.

[0041] 2. Industrial equipment compatibility: Table 2

[0042] 3. Industrialization Implementation Cases: Cooperation model: Partner with a leading dairy company in a region, leveraging its existing cold chain logistics system to cover 200+ chain supermarkets and online e-commerce platforms; Market data: Within three months of its launch, monthly sales increased from 15 tons to 50 tons, and the market share of plant-based fermented dairy products in the region reached 8%; consumer surveys (n=500) showed a 92% satisfaction rate with taste, an 89% satisfaction rate with flavor, and an 85% repurchase intention rate. Benefit analysis: After the project reaches full production capacity, the annual production capacity will be 30,000 tons, the annual sales revenue will be 105 million yuan, the net profit will be 18 million yuan, and it will create more than 200 jobs in the millet planting base, realizing the added value of deep processing of agricultural products (the added value of millet raw materials will be increased by more than 3 times).

[0043] 4. Industrialization data verification: (1) Nutritional composition comparison table (unit: g / 100mL) Table 3

[0044] (2) Cost Structure Comparison Table (Unit: Yuan / L) Table 4

[0045] (3) Stability test data Table 5

[0046] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing fermented milk from millet enzymatic hydrolysate, characterized in that, Includes the following steps: After mixing millet hydrolysate with milk, the mixture is successively subjected to gel milling, homogenization, and sterilization. Then, it is inoculated with a compound fermentation agent for fermentation. After fermentation, it undergoes post-fermentation to produce the millet hydrolysate fermented milk.

2. The preparation method according to claim 1, characterized in that, The ratio of the millet enzymatic hydrolysate to milk is 6g:100mL.

3. The preparation method according to claim 1, characterized in that, The conditions for the gel milling are as follows: a two-stage continuous gel milling process is adopted, with the first stage of gel milling lasting 10 minutes and the second stage lasting 8 minutes.

4. The preparation method according to claim 1, characterized in that, The homogenization conditions are as follows: first, treat with low pressure of 30 MPa for 2 minutes, then treat with high pressure of 60 MPa for 2 minutes.

5. The preparation method according to claim 1, characterized in that, The sterilization temperature was 121 °C and the time was 8 seconds.

6. The preparation method according to claim 1, characterized in that, The compound fermentation agent was purchased from Beijing Shengmu Catering Management Co., Ltd.

7. The preparation method according to claim 1, characterized in that, The fermentation conditions are as follows: 1 mg of compound fermentation agent is added per 100 mL of milk, the fermentation temperature is 42℃, and the fermentation time is 7~9 hours.

8. The preparation method according to claim 1, characterized in that, The post-ripening conditions are: refrigeration at 4 ℃ for 8-10 h.

9. Fermented milk made from millet enzymatic hydrolysate prepared by any one of claims 1-8.

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