A dairy product and a method for its preparation

Abstract

The present application relates to the field of dairy products, in particular to a dairy product and a preparation method thereof, more particularly to a dairy product containing Astragalus membranaceus and a preparation method thereof. The present application maintains the viable number of probiotics in the dairy product during the shelf life by adding Astragalus membranaceus to the raw materials of the dairy product.

Description

Technical Field

[0001] This invention belongs to the field of dairy products, specifically relating to a dairy product and its preparation method, and more specifically to a dairy product containing Astragalus membranaceus and its preparation method. Background Technology

[0002] As consumers become more aware of and concerned about probiotics, they are being widely used in food, especially probiotic fermented milk, whose beneficial functions for the human body have been proven. Probiotic fermented milk is not only rich in beneficial microorganisms such as lactic acid bacteria, but also produces a variety of bioactive substances through the fermentation process, providing multiple health benefits.

[0003] Commonly used probiotics include Bifidobacterium, Lactobacillus acidophilus, and Lactobacillus casei. To obtain the benefits of probiotics, choosing products with a high probiotic content is better. However, the number of live probiotics in commercially available probiotic dairy products gradually decreases with prolonged storage. Therefore, maintaining the probiotic content of probiotic dairy products throughout their shelf life is currently a challenge for the industry. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides dairy products containing astragalus, which can maintain the content of probiotics during the shelf life of dairy products.

[0005] A first aspect of the present invention provides a dairy product prepared from raw materials, said raw materials including: Astragalus membranaceus, Bifidobacterium, and liquid milk raw materials.

[0006] In some embodiments, the dairy product is a fermented dairy product, such as fermented milk or lactic acid bacteria beverage.

[0007] In some embodiments, the astragalus is astragalus powder.

[0008] In some embodiments, the astragaloside A content in the astragalus powder is ≥0.1wt%, for example 0.1-10wt%, 0.1-5wt%, 0.1-1.0wt%, 0.1-0.5wt%, for example 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 1.5wt%, 2.0wt%, 2.5wt%, 3.0wt%, 3.5wt%, 4.0wt%, 4.5wt%, 5.0wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%.

[0009] In some embodiments, the astragalus powder is obtained by water extraction from astragalus roots. In some embodiments, the astragalus powder is produced from the dried roots of *Astragalus membranaceus* (Fisch.) Bunge or *Astragalus membranaceus* (Fisch.) Bge. through a process of coarse crushing, extraction, concentration, sterilization, and drying. In some embodiments, the astragalus is a liquid astragalus-based raw material, the content of which is converted from the content of astragaloside A.

[0010] In some embodiments, the amount of astragalus powder added is 0.1–9 wt‰, for example, 0.1–6 wt‰, based on the total weight of the dairy raw materials. In some embodiments, the amount of astragalus powder added is 0.1–3 wt‰, based on the total weight of the dairy raw materials. In some embodiments, the amount of astragalus powder added is 0.1–1.5 wt‰, based on the total weight of the dairy raw materials. In some embodiments, the amount of Astragalus powder added, based on the total weight of the dairy raw materials, is 0.1wt‰, 0.2wt‰, 0.3wt‰, 0.4wt‰, 0.5wt‰, 0.6wt‰, 0.7wt‰, 0.8wt‰, 0.9wt‰, 1.0wt‰, 1.1wt‰, 1.2wt‰, 1.3wt‰, 1.4wt‰, 1.5wt‰, 1.7wt‰, 2wt‰, 2.3wt‰, 2.5wt‰, 2.7wt‰, 3wt‰, 3.5wt‰, 4wt‰, 4.5wt‰, 5wt‰, 6wt‰, 7wt‰, 8wt‰, or 9wt‰.

[0011] In some embodiments, the Bifidobacterium is Bifidobacterium lactis.

[0012] In some embodiments, the Bifidobacterium lactis is Bifidobacterium lactis BL-99, and the preservation number of Bifidobacterium lactis BL-99 is CGMCC No. 15650.

[0013] In some embodiments, the inoculation amount of Bifidobacterium is 0.001–1.5 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of Bifidobacterium is 0.005–0.75 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of Bifidobacterium is 0.01–0.15 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of Bifidobacterium, based on the total weight of the dairy raw materials, is 0.001wt‰, 0.003wt‰, 0.005wt‰, 0.007wt‰, 0.01wt‰, 0.02wt‰, 0.03wt‰, 0.04wt‰, 0.05wt‰, 0.06wt‰, 0.07wt‰, 0.08wt‰, 0.09wt‰, 0.1wt‰, 0.11wt‰, 0.12wt‰, 0.13wt‰, 0.14wt‰, 0.15wt‰, 0.17wt‰, 0.2wt‰, 0.3wt‰, 0.4wt‰, 0.5wt‰, 0.6wt‰, 0.7wt‰, 0.8wt‰, or 0.9wt‰.

[0014] In some embodiments, the liquid milk raw material is one or more of fresh milk, reconstituted milk, whole milk, skim milk, and low-fat milk. The liquid milk raw material described in this invention refers to fresh milk or reconstituted milk that meets my country's standards for raw milk procurement, including whole milk, skim milk, and low-fat milk. In some embodiments, the liquid milk raw material is one or more of whole milk, partially skimmed milk, and completely skimmed milk. In some embodiments, the liquid milk raw material can be obtained by spray-drying the aforementioned materials. In some embodiments, the amount of liquid milk raw material added is the remainder after removing other raw materials, based on the total weight of the dairy raw materials, for example 50-99.99 wt%, 60-99.99 wt%, 70-99.99 wt%, 80-99.99 wt%, 85-99.99 wt%, for example 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%.

[0015] In some embodiments, the raw materials also include a fermentation agent.

[0016] In some embodiments, the fermenting agent is one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus helveticus, Lactobacillus bulgaricus, and Streptococcus thermophilus.

[0017] In some embodiments, the inoculation amount of the starter culture is 0.0001–1.0 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of the starter culture is 0.0001–0.1 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of the starter culture is 0.001–0.07 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of the starter culture is 0.01–0.05 wt‰ based on the total weight of the dairy raw materials. In some embodiments, the inoculation amount of the starter culture, based on the total weight of the dairy raw materials, is 0.0001 wt‰, 0.0005 wt‰, 0.001 wt‰, 0.003 wt‰, 0.005 wt‰, 0.007 wt‰, 0.01 wt‰, 0.02 wt‰, 0.03 wt‰, 0.04 wt‰, 0.05 wt‰, 0.06 wt‰, 0.07 wt‰, 0.08 wt‰, 0.09 wt‰, or 0.1 wt‰.

[0018] In some embodiments, the raw materials further include additives, which are one or more of the following: sweeteners, flavorings, acidity regulators, stabilizers, fatty ingredients, protein ingredients, water, dietary fiber, compound nutrients, fruit and vegetable juices, and salt. In some embodiments, the additives are sweeteners.

[0019] In some embodiments, the sweetening substance is a sugar or a sweetener.

[0020] In some embodiments, the sugar is one or more of the following: granulated sugar, starch sugar, sucrose, glucose, fructose, galactose, high-fructose corn syrup, and maltose.

[0021] In some embodiments, the sugar is one or more of glucose, fructose, galactose, and high-fructose corn syrup.

[0022] In some embodiments, the amount of carbohydrates added is 0.05–20 wt% based on the total weight of the dairy raw materials. In some embodiments, the amount of carbohydrates added is 0.1–15 wt% based on the total weight of the dairy raw materials. In some embodiments, the amount of carbohydrates added is 0.2–12 wt%, for example, 0.2–10 wt% based on the total weight of the dairy raw materials. In some embodiments, the amount of carbohydrates added is 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, or 15 wt% based on the total weight of the dairy raw materials.

[0023] In some embodiments, the acidity regulator is one or more of lactic acid, citric acid, malic acid, tartaric acid, and phosphoric acid.

[0024] In some embodiments, the amount of acidity regulator added is 0.001 wt% to 1 wt% based on the total weight of the dairy raw materials.

[0025] In some embodiments, the stabilizer is one or more of pectin, carboxymethyl cellulose, gellan gum, propylene glycol alginate, and soluble soybean polysaccharides.

[0026] In some embodiments, the stabilizer is soluble soybean polysaccharide and / or pectin.

[0027] In some embodiments, the amount of soluble soybean polysaccharide added is less than 0.8 wt% and the amount of pectin added is less than 0.3 wt% based on the total weight of the dairy raw materials. Whether the product contains both soluble soybean polysaccharide and pectin, or only one of them, the amounts are within the above range. If sweeteners and soluble soybean polysaccharides are added simultaneously, the amount of soluble soybean polysaccharide added can be reduced accordingly.

[0028] In some embodiments, the fat and protein ingredients are selected from light cream, butter, anhydrous butter, condensed milk, sweetened condensed milk, whey protein concentrate, milk protein concentrate, and any combination thereof.

[0029] In some implementations, the selection and amount of substances (e.g., additives) used in the raw materials can be determined by those skilled in the art based on actual needs.

[0030] In some embodiments, the fermented milk or lactic acid bacteria beverage provided by the present invention is a white fermented milk or a white lactic acid bacteria beverage. In some embodiments, the fermented milk or lactic acid bacteria beverage provided by the present invention is made into a brown fermented milk or a brown lactic acid bacteria beverage through the Maillard reaction. When making the milk base for brown fermented milk or brown lactic acid bacteria beverage, one or more of glucose, fructose, galactose, and high-fructose corn syrup are generally added. Browning treatment can be performed by first using lactase to hydrolyze the lactose in milk or reconstituted milk, and then performing browning treatment.

[0031] A second aspect of the present invention provides the dairy product described in the first aspect of the present invention, which is prepared by a method comprising the following steps:

[0032] (1) Mix astragalus, liquid milk raw materials and optional additives;

[0033] (2) Sterilize or brown the product from step (1);

[0034] (3) Inoculate Bifidobacterium into the product of step (2), and optionally, inoculate a starter culture at the same time;

[0035] (4) Ferment the product from step (3).

[0036] A third aspect of the present invention provides a method for preparing the dairy product described in the first aspect of the present invention, comprising:

[0037] (1) Mix astragalus, liquid milk raw materials and optional additives;

[0038] (2) Sterilize or brown the product from step (1);

[0039] (3) Inoculate Bifidobacterium into the product of step (2), and optionally, inoculate a starter culture at the same time;

[0040] (4) Ferment the product from step (3).

[0041] In some implementations, step (1) includes:

[0042] 1.1) Mix the astragalus powder, liquid milk raw materials, and optional additives;

[0043] 1.2) Homogenize the product from step 1.1).

[0044] In some embodiments, the stirring described in step 1.1) is carried out at 30-70°C for 20-50 minutes, for example at 45-65°C for 30-40 minutes.

[0045] In some embodiments, the homogenization described in step 1.2) is carried out at 60-70°C and 15-30 MPa, for example at 65°C or 20 MPa.

[0046] In some implementations, the sterilization temperature in step (2) is 93-97°C and the time is 5-10 min.

[0047] In some implementations, the browning treatment in step (2) is performed at a temperature of 110-120°C for 5-10 minutes.

[0048] In some implementations, the browning treatment in step (2) is performed at a temperature of 90-100°C for 2-4 hours, for example, at 93-97°C for 3-4 hours.

[0049] In some implementations, the inoculation temperature in step (3) is 37°C-42°C.

[0050] In some implementations, the fermentation temperature in step (4) is 37°C-42°C.

[0051] In some implementations, the fermentation in step (4) is terminated at an acidity of 70-80°C or pH ≤ 4.6.

[0052] In some implementations, the fermentation in step (4) is terminated at an acidity of 160°T.

[0053] In some implementations, step (5A) is also included: saving.

[0054] In some implementations, step (5A) includes: cooling the product of step (4) to 2-6°C and refrigerating it for about 12-24 hours.

[0055] In some embodiments, step (5A) includes: demulsifying and cooling the product from step (4) to 20-25°C, filling it, and refrigerating it at 2-6°C for approximately 12-24 hours for post-ripening.

[0056] In some embodiments, step (5A) includes: homogenizing the product of step (4) and then filling it, wherein the homogenization pressure is 0-10 MPa and the homogenization temperature is ≤20°C, for example 10-20°C.

[0057] In some implementations, it also includes:

[0058] (5B) Prepare the diluent;

[0059] (6) Mix the product from step (4) with the diluent.

[0060] In some implementations, step (5B) includes:

[0061] 5B.1) Mix one or more of the following ingredients: sweetener, stabilizer, flavoring, acidity regulator, fat, protein, water, dietary fiber, complex nutrients, fruit and vegetable juice, and salt.

[0062] 5B.2) Sterilize the product from step 5B.1) to obtain a diluted solution.

[0063] In some embodiments, the stirring time described in step 5B.1) is 20-50 min, for example 30-40 min.

[0064] In some implementations, the sterilization described in step 5B.2) is pasteurization.

[0065] In some implementations, the sterilization temperature in step 5B.2) is 95°C and the time is 300s.

[0066] In some implementations, step (6) includes:

[0067] 6.1) Homogenize the product from step (4) to obtain milk base;

[0068] 6.2) Mix the milk base with the diluent.

[0069] In some embodiments, the milk base content is 20-75 wt% based on the total weight of the finished dairy product, for example 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, and 70 wt%.

[0070] In some implementations, the homogenization temperature in step 6.1) is 20-30°C and the pressure is 15-30 MPa, for example, the temperature is 20°C and the pressure is 20 MPa.

[0071] In some embodiments, homogenization is further included after step 6.2). In some embodiments, the homogenization temperature is ≤20°C and the pressure is 15-30 MPa, for example, the temperature is 10-20°C and the pressure is 20 MPa.

[0072] In some embodiments, the present invention provides a method for preparing fermented milk, comprising:

[0073] (A1) Preparation: Heat the liquid milk raw material to 65°C, start stirring and then directly add one or more of the following: astragalus powder, sweetener, stabilizer, fat raw material and protein raw material, and stir for 30-40 minutes to prepare the raw material.

[0074] (B1) Homogenization: Homogenize the liquid after chemical processing. Before homogenization, preheat to 60-70℃ and homogenize at a pressure of 15-30MPa.

[0075] (C1) Sterilization: Sterilize the homogenized liquid at 93-97℃ for 5-10 minutes.

[0076] (D1) Cooling and inoculation: Cool the sterilized liquid to the inoculation temperature of 37-42℃ and inoculate with Bifidobacterium. Optionally, inoculate with a starter culture at the same time.

[0077] (E1) Fermentation: Fermentation is terminated when the acidity of the liquid reaches 70-80°C or pH ≤ 4.6. Fermentation can be terminated once either the acidity index or the pH index meets the requirements.

[0078] In some implementations, the inoculated liquid from step (D1) is filled into unit packaging, and then the temperature is maintained at 41-43°C for 4-5 hours for fermentation. When the acidity reaches 70-75°C, the product is cooled to 2-6°C and refrigerated for about 12-24 hours to obtain a coagulated fermented milk product.

[0079] In some implementations, the fermentation product from step (E1) is demulsified and immediately cooled to 20-25°C, then bottled. After bottling, it is refrigerated at 2-6°C for approximately 12-24 hours to mature, resulting in a stirred fermented milk product.

[0080] In some embodiments, the fermentation product from step (E1) above is homogenized twice at a pressure of 0-10 MPa and a temperature of ≤20°C (e.g., 10-20°C), and then bottled to obtain a beverage-grade fermented milk product.

[0081] In some embodiments, the present invention provides a method for preparing a lactic acid bacteria beverage, comprising:

[0082] (A2) Preparation and hydration: Heat the liquid milk raw material to 40-65℃, then add one or more of the following: sweetener, astragalus powder, stabilizer, fat raw material and protein raw material, and stir for 20-50 minutes, for example, 30-40 minutes to prepare the raw material;

[0083] (B2) Homogenization: Homogenize the chemical and hydrated materials. Preheat the material to about 65°C before homogenization and the homogenization pressure is 15-30MPa.

[0084] (C2) Sterilization or browning treatment: Sterilize the homogenized liquid at 93-97°C for 5-10 minutes; or, brown the homogenized liquid at 93-97°C for 180-240 minutes.

[0085] (D2) Cooling and inoculation: Cool the solution after step (C2) to the inoculation temperature of 37℃-42℃ and inoculate with Bifidobacterium;

[0086] (E2) Fermentation: Fermentation is terminated when the acidity reaches 70-80°T, and the fermentation time is 4-6 hours. Alternatively, for products after browning treatment, fermentation is terminated when the acidity reaches above 160°T.

[0087] (F2) Homogenization and cooling: Cool the fermented liquid to room temperature and homogenize it under aseptic conditions at a pressure of 15-30 MPa to obtain the milk base.

[0088] (G2) Preparation of milk base diluent: Mix one or more of the following: white sugar, stabilizer, sweetener and water, stir for 30-40 minutes to dissolve, then pasteurize at 95℃ for 300 seconds, and cool to below 30℃ after pasteurization for later use.

[0089] (H2) Beverage preparation: The amount of milk base added is 20-75% of the total weight of the active lactic acid bacteria beverage. At the same time, the above-mentioned milk base dilution is added, and then the mixture is homogenized at low temperature with a homogenization pressure of 15-30 MPa to obtain the lactic acid bacteria beverage.

[0090] Terminology Definition

[0091] In this application, unless otherwise stated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, to better understand this invention, definitions and explanations of relevant terms are provided below.

[0092] The equipment used in the production process of this invention, such as homogenizers for homogenization, mixing tanks for mixing, fermentation tanks for fermentation, and sterilization equipment, can all be equipment known in the art. The filling of the liquid dairy products of this invention can also be carried out in accordance with the existing liquid product filling technology in the art.

[0093] When the term “for example” or its variations are used in this document, these terms will not be considered restrictive terms, but will be interpreted as meaning “including but not limited to” or “not limited to”.

[0094] When this article uses the term “including” or variations thereof, it also provides the meanings of the terms “consisting of” and “substantially composed of”.

[0095] Unless otherwise specified herein or clearly contradicted by the context, the terms “a” and “the”, as well as similar designations, shall be interpreted to cover both the singular and the plural in the context of describing the invention (especially in the context of the following claims).

[0096] Unless otherwise stated, all proportions, contents, amounts added, etc., involved in this invention refer to weight proportions and contents.

[0097] In this application, the term "reconstituted milk" is also called "reconstituted milk" or "reconstituted milk," referring to an emulsion made by adding an appropriate amount of water to solid milk powder (such as whole milk powder, skim milk powder, and low-fat milk powder) to prepare an emulsion with a water-to-solids ratio equivalent to that in original milk.

[0098] In this application, the term "one or more" includes one, two or more combinations, such as one, two, three, four, etc.

[0099] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0100] Beneficial effects

[0101] This invention adds astragalus powder to dairy product raw materials, which helps maintain the number of live probiotics in dairy products during their shelf life, especially for Bifidobacterium lactis BL-99. Detailed Implementation

[0102] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0103] Examples 1-9: A stirred probiotic fermented milk containing astragalus powder

[0104] 1.1 Raw material formula (based on a total raw material quantity of 1000 kg):

[0105] Table A

[0106] raw material weight Astragalus powder 0.1-9kg white sugar 70kg Fermentation starter (Lactobacillus bulgaricus: Streptococcus thermophilus = 2:1) 50g Bifidobacterium lactis BL-99 10g milk margin

[0107] The starter culture was purchased from Chr. Hansen (Beijing) Trading Co., Ltd., and Bifidobacterium lactis BL-99 is a strain with independent intellectual property rights of Yili, with the preservation number CGMCC No.15650.

[0108] Astragalus powder is produced from the dried roots of Astragalus membranaceus from Inner Mongolia through coarse crushing, water extraction, concentration, sterilization, and drying. The astragaloside A content is 0.1%. In Examples 1-9, the weight content of the astragalus powder is 0.1‰, 0.3‰, 0.6‰, 0.9‰, 1.2‰, 1.5‰, 3‰, 6‰, and 9‰, respectively.

[0109] 1.2 The production of Examples 1-9 shall be carried out according to the following operations:

[0110] (1) Preparation: Heat the milk to 65°C, turn on the stirring and then directly add astragalus powder and white sugar, stir for 30 minutes to prepare the ingredients;

[0111] (2) Homogenization: The liquid after chemical processing is homogenized. Before homogenization, it is preheated to about 65°C and the homogenization pressure is 20MPa.

[0112] (3) Sterilization: Sterilize the homogenized liquid at 95°C for 5 minutes.

[0113] (4) Cooling and inoculation: Cool the sterilized liquid to the inoculation temperature of 42°C, and inoculate with the starter and Bifidobacterium lactis BL-99;

[0114] (5) Fermentation: After inoculation, fermentation is carried out at 42℃. Fermentation is terminated when the pH value of the liquid is lower than 4.6 or the acidity of the product reaches 70°T or above. Fermentation can be terminated as long as either the acidity index or the pH index meets the requirements.

[0115] The fermentation product is broken up and immediately cooled to 20°C before being bottled. After bottling, it is refrigerated at 2-6°C for approximately 12 hours to mature, yielding the stirred probiotic fermented milk product.

[0116] Comparative Example 1

[0117] The raw materials did not contain astragalus powder, and the other raw materials and production operations were the same as in Examples 1-9.

[0118] Test Example 1. Effect of Astragalus Powder on Product Fermentation State

[0119] Fermentation was terminated when the pH of the fermented product was ≤4.6. The fermentation time was recorded, and the state of the fermented product was observed. The results are shown in Table 1.

[0120] Table 1. Effects of different amounts of Astragalus powder on fermentation time of stirred probiotic fermented milk.

[0121]

[0122]

[0123] The experimental results from the above examples and comparative examples show that when the amount of Astragalus powder added is in the range of 0.1 to 3‰, the fermentation time is about 4.5 to 5 hours, which has no effect on the fineness and uniformity of the cross-section of the fermented product. When the amount of Astragalus powder added is ≥6‰, the fermentation time is extended to 5.5 to 6 hours, which affects the fermentation state of the product and causes the formation of fine particles.

[0124] Test Example 2. Effect of Astragalus Powder on Product pH During Shelf Life

[0125] This experiment used a Mettler Toledo pH electrode to directly measure the pH of the product during its shelf life. Two parallel samples were measured each time, and the average value was taken. The results were rounded to three decimal places and are shown in Table 2.

[0126] Table 2. Effects of different amounts of Astragalus powder on product pH during shelf life.

[0127]

[0128] As shown in Table 2, when the amount of Astragalus powder added is 0.1-9‰, it has no significant effect on the pH of the product during the 28-day shelf life.

[0129] Test Example 3. Effect of Astragalus Powder on Viable Bacterial Count in Products During Shelf Life

[0130] This experiment used the method specified in the National Food Safety Standard for Microbiological Examination of Food (GB 4789.34-2016) to determine the number of Bifidobacteria in the product during its shelf life. The results are shown in Table 3.

[0131] Table 3. Effects of different amounts of Astragalus powder on the viable bacterial count of the product during shelf life.

[0132]

[0133] *This specifically refers to the total number of Bifidobacteria in the product.

[0134] Table 3 shows that when fermenting to obtain stirred probiotic fermented milk, the number of viable Bifidobacteria was comparable between the product with added astragalus powder and the product without added astragalus powder. However, when the shelf life was extended to day 28, the number of viable bacteria in the product with added astragalus powder was significantly higher than that in the product without added astragalus powder, with a difference reaching orders of magnitude. This indicates that adding astragalus powder helps maintain the number of viable Bifidobacteria in fermented milk products throughout their shelf life.

[0135] Test Example 4. The effect of Astragalus powder on product taste during shelf life

[0136] Twenty people tasted the product stored at 6℃ for 7 days and evaluated it according to Table 4-1 below. If there was any off-flavor, please fill in the corresponding flavor. The tasting results are shown in Table 4-2.

[0137] Table 4-1

[0138]

[0139]

[0140] Table 4-2 Effects of different amounts of Astragalus powder added on the taste of stirred probiotic fermented milk

[0141]

[0142] According to the tasting results, when the amount of astragalus powder added is between 0.1 and 1.5‰, the product has a moderately sweet and sour taste with no off-flavors. Gradually increasing the amount of astragalus powder added to 9‰ brings a herbal flavor without any unpleasant taste.

[0143] As can be seen from the above test examples 1-4, the probiotic fermented milk product containing astragalus powder produced in this embodiment has a good flavor, refreshing taste, stable acidity during the shelf life, and can still maintain a high number of live bacteria even after a shelf life of 28 days, without any unpleasant taste.

[0144] Examples 10-18: A lactic acid bacteria beverage containing astragalus powder

[0145] 1.1 Raw material formula (based on a total raw material quantity of 1000 kg):

[0146] Table B

[0147]

[0148]

[0149] The sources of Bifidobacterium lactis BL-99 and Astragalus membranaceus powder are the same as in Examples 1-9. In Examples 10-18, the weight content of Astragalus membranaceus powder is 0.1‰, 0.3‰, 0.6‰, 0.9‰, 1.2‰, 1.5‰, 3‰, 6‰, and 9‰, respectively.

[0150] 1.2 The production of Examples 10-18 shall be carried out according to the following operations:

[0151] (1) Preparation and hydration: Heat some pure water to 45°C, then add 95kg skim milk powder, 10kg glucose and the corresponding amount of astragalus powder, and turn on the stirrer to prepare and hydrate for 45 minutes.

[0152] (2) Homogenization: Homogenize the chemical and hydrated liquid. Preheat the mixture to about 65°C before homogenization and the homogenization pressure is 15MPa.

[0153] (3) Sterilization: Sterilize the homogenized liquid at 95°C for 5 minutes.

[0154] (4) Cooling and inoculation: Cool the sterilized liquid to the inoculation temperature of 37°C and inoculate with Bifidobacterium lactis BL-99;

[0155] (5) Fermentation: After inoculation, fermentation is carried out at 37°C. Fermentation is terminated when the acidity reaches 130°T.

[0156] (6) Homogenization and cooling: Cool the fermented liquid to room temperature and homogenize it under aseptic conditions at a pressure of 15 MPa to obtain the milk base.

[0157] (7) Preparation of diluent: Dissolve white sugar (addition amount as shown in Table B) in pure water to prepare sugar water, then pasteurize at 95℃ for 300 seconds, and cool down to below 30℃ for later use.

[0158] (8) Beverage preparation: The amount of milk base added is 34% of the total weight of the active lactic acid bacteria beverage. The remaining amount is made up with the prepared sugar water. Then the mixture is homogenized at low temperature (below 20°C) with a homogenization pressure of 18 MPa.

[0159] Comparative Example 2

[0160] There is no astragalus powder in the raw materials, and the other raw materials and production operations are the same as in Examples 10-18.

[0161] Test Example 5. Effect of Astragalus Powder on the Acidity of Lactic Acid Bacteria Beverages

[0162] This experiment adopted the method specified in the National Food Safety Standard for Determination of Acidity in Food (GB 5009.239-2016), and used a Mettler G10S acidity titrator to determine the acidity of the product. Two parallel samples were measured each time, and the average value was taken. The results were retained to one decimal place. The results are shown in Table 5.

[0163] Table 5. Effects of different amounts of Astragalus powder added on the acidity of active lactic acid bacteria beverages during shelf life.

[0164]

[0165] As shown in Table 5, when the amount of Astragalus powder added is 0.1-9‰, it has no significant effect on the acidity of lactic acid bacteria beverages within a 28-day shelf life.

[0166] Test Example 6. Effect of Astragalus Powder on the Viable Bacterial Count of the Product

[0167] This experiment used the method specified in the National Food Safety Standard for Microbiological Examination of Food (GB 4789.34-2016) to determine the number of Bifidobacteria in the product. The results are shown in Table 6.

[0168] Table 6. Effects of different amounts of Astragalus powder on the number of viable bacteria in active lactic acid bacteria beverages during shelf life.

[0169]

[0170]

[0171] *This specifically refers to the total number of Bifidobacteria in the product.

[0172] Table 6 shows that when preparing lactic acid bacteria beverages, the number of viable Bifidobacteria in the product with added astragalus powder was comparable to that in the product without added astragalus powder. However, when the shelf life was extended to day 28, the number of viable bacteria in the product with added astragalus powder was significantly higher than that in the product without added astragalus powder, with a difference reaching orders of magnitude. This indicates that adding astragalus powder helps maintain the number of viable Bifidobacteria in lactic acid bacteria beverages throughout their shelf life. Furthermore, within the range of 0.1–6‰, the number of viable bacteria on day 28 increased accordingly with increasing astragalus powder dosage, indicating that the protective effect of astragalus powder on viable bacteria is dose-related.

[0173] Test Example 7. Effect of Astragalus Powder on the Stability of Lactic Acid Bacteria Beverages

[0174] The test samples were dispensed into 250mL blue-capped bottles, with the liquid added to the 200mL mark in each bottle. The water separation height was measured along the wall using a transparent flexible ruler. The evaluation criteria were as follows: water separation height ≤ 2mm: no water separation; 2mm ≤ water separation height ≤ 4mm: slight water separation; 4mm ≤ water separation height ≤ 8mm: slight water separation; 8mm ≤ water separation height: partial water separation; partial water separation was considered unacceptable. The results are shown in Table 7. Color changes were also observed.

[0175] Table 7. Effects of different amounts of Astragalus powder on the shelf-life stability of active lactic acid bacteria beverages.

[0176]

[0177]

[0178] According to the stability test results, when the amount of Astragalus powder added is 0.1-9‰, the product has no sedimentation, layering, uniform texture, and no color change within a 28-day shelf life.

[0179] Test Example 8. Effect of Astragalus Powder on the Taste of Lactic Acid Bacteria Beverages During Shelf Life

[0180] Taste the product stored at 6℃ for 7 days and evaluate it according to Table 8-1 below. If there is any off-flavor, please fill in the corresponding taste. The tasting results are shown in Table 8-2.

[0181] Table 8-1

[0182]

[0183] Table 8-2 Effects of different amounts of Astragalus powder on the taste of active lactic acid bacteria beverages

[0184]

[0185] According to the tasting results, when the amount of astragalus powder added is 0.1 to 0.6‰, the product has a moderately sweet and sour taste with no off-flavors. When the amount of astragalus powder added is 0.9 to 1.2‰, there is a slight herbal aroma. When the amount of astragalus powder added is 1.5 to 9‰, the herbal aroma is obvious with no unpleasant taste.

[0186] As can be seen from the above test examples 5-8, the active lactic acid bacteria beverage containing astragalus powder produced in this embodiment has a good flavor, refreshing taste, and remains stable during its shelf life. By the 28-day shelf life, there was no unacceptable stratification or sedimentation, no unpleasant taste, and it can maintain a high number of live bacteria.

[0187] Comparative Examples 3-4

[0188] In Comparative Example 3, the amount of astragalus powder added was 1.5‰. Other raw materials and production operations were the same as in Example 15, except that the timing of astragalus powder addition was changed from the chemical preparation and hydration in step (1) to adding it during beverage preparation in step (8), and fermentation was terminated when the acidity reached 135°T. In Comparative Example 4, no astragalus powder was used in the raw materials. Other raw materials and production operations were the same as in Example 15, except that fermentation was terminated when the acidity reached 141°T. The viable count of Bifidobacteria in the resulting lactic acid bacteria beverage was tested.

[0189] Table 9. Effects of Astragalus Powder on the Dioscorea Bacteria in Active Lactic Acid Bacteria Beverages The effect of Propionibacterium fermentation

[0190] Sample number Astragalus powder addition amount ‰ Fermentation acidity viable bacteria count (CFU / mL) (6℃) Example 15 1.5 <![CDATA[130 o T]]> 1.25E+09 Comparative Example 3 1.5 <![CDATA[135 o T]]> 1.82E+09 Comparative Example 4 0 <![CDATA[141 o T]]> 2.62E+09

[0191] As shown in Table 9, adding astragalus powder before fermentation (Example 15) and after fermentation (Comparative Example 3) resulted in no significant difference in the number of viable Bifidobacteria in the produced lactic acid bacteria beverage compared to not adding astragalus powder (Comparative Example 4). Therefore, adding astragalus powder does not promote the growth of Bifidobacterium BL-99 during fermentation.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A dairy product prepared from raw materials, said raw materials comprising: Astragalus, Bifidobacterium, and liquid milk ingredients; Preferably, the dairy product is a fermented dairy product, such as fermented milk or lactic acid bacteria beverage.

2. The dairy product according to claim 1, wherein, The astragalus mentioned is astragalus powder; Preferably, the astragaloside A content in the astragalus powder is ≥0.1wt%, for example, 0.1-1.0wt%. Preferably, the astragalus powder is obtained by water extraction from astragalus root. Preferably, the amount of Astragalus powder added is 0.1-9 wt‰, more preferably 0.1-3 wt‰, and more preferably 0.1-1.5 wt‰, based on the total weight of the dairy raw materials.

3. The dairy product according to claim 1 or 2, wherein, The Bifidobacterium is Bifidobacterium lactis; Preferably, the Bifidobacterium lactis is Bifidobacterium lactis BL-99, and the preservation number of Bifidobacterium lactis BL-99 is CGMCC No.15650; Preferably, the inoculation amount of Bifidobacterium is 0.001 to 1.5 wt‰, more preferably 0.005 to 0.75 wt‰, and even more preferably 0.01 to 0.15 wt‰, based on the total weight of the dairy raw materials.

4. The dairy product according to any one of claims 1-3, wherein, The liquid milk raw material is one or more of the following: fresh milk, reconstituted milk, whole milk, skim milk, and low-fat milk.

5. The dairy product according to any one of claims 1-4, wherein, The raw materials also include a fermentation agent. Preferably, the fermenting agent is one or more of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus helveticus, Lactobacillus bulgaricus, and Streptococcus thermophilus. Preferably, the inoculation amount of the starter culture is 0.0001 to 0.1 wt‰, more preferably 0.001 to 0.07 wt‰, and more preferably 0.01 to 0.05 wt‰, based on the total weight of the dairy raw materials. More preferably, the raw materials further include additives, which are one or more of the following: sweeteners, flavorings, acidity regulators, stabilizers, fatty ingredients, protein ingredients, water, dietary fiber, compound nutrients, fruit and vegetable juices, and salt. Preferably, the sweetening substance is a sugar or a sweetener. Preferably, the sugar is one or more of the following: granulated sugar, starch sugar, sucrose, glucose, fructose, galactose, high-fructose corn syrup, and maltose. Preferably, based on the total weight of the dairy raw materials, the amount of sugar added is 0.05-20 wt%, more preferably 0.1-15 wt%, and more preferably 0.2-12 wt%. Preferably, the acidity regulator is one or more of lactic acid, citric acid, malic acid, tartaric acid, and phosphoric acid. Preferably, the stabilizer is one or more of pectin, carboxymethyl cellulose, gellan gum, propylene glycol alginate, and soluble soybean polysaccharides; more preferably, the stabilizer is soluble soybean polysaccharides and / or pectin. Preferably, the fat and protein ingredients are selected from light cream, butter, anhydrous butter, condensed milk, sweetened condensed milk, whey protein concentrate, milk protein concentrate, and any combination thereof.

6. The dairy product according to any one of claims 1-5, wherein it is prepared by a method comprising the following steps: (1) Mix astragalus, liquid milk raw materials and optional additives; (2) Sterilize or brown the product from step (1); (3) Inoculate Bifidobacterium into the product of step (2), and optionally, inoculate a starter culture at the same time; (4) Ferment the product from step (3).

7. A method for preparing the dairy product according to any one of claims 1-5, comprising: (1) Mix astragalus, liquid milk raw materials and optional additives; (2) Sterilize or brown the product from step (1); (3) Inoculate Bifidobacterium into the product of step (2), and optionally, inoculate a starter culture at the same time; (4) Ferment the product from step (3).

8. The dairy product of claim 6 or the method of claim 7, wherein, Step (1) includes: 1.1) Mix the astragalus powder, liquid milk raw materials, and optional additives; 1.2) Homogenize the product from step 1.1); Preferably, the stirring is carried out at 30-70°C (e.g., 45-65°C) for 20-50 minutes (e.g., 30-40 minutes); Preferably, the homogenization is carried out at 60-70℃ and 15-30MPa.

9. The dairy product of claim 6 or the method of claim 7 or 8, wherein, Steps (2) to (4) have one or more of the following characteristics: - The sterilization temperature in step (2) is 93-97℃ and the time is 5-10 min; - The inoculation temperature in step (3) is 37℃-42℃; - The fermentation temperature in step (4) is 37℃-42℃; - The fermentation in step (4) is terminated at an acidity of 70-80°C or pH ≤ 4.

6.

10. The dairy product of claim 6 or the method of claim 7 or 8, wherein steps (2) to (4) have one or more of the following features: - The browning treatment in step (2) is performed at a temperature of 110-120℃ for 5-10 min, or at a temperature of 90-100℃ for 2-4 h, for example, at 93-97℃ for 3-4 h; - The inoculation temperature in step (3) is 37℃-42℃; - The fermentation temperature in step (4) is 37℃-42℃; - The termination acidity of fermentation in step (4) is 160°T.

11. The dairy product of claim 6 or the method of any one of claims 7-10, further comprising step (5A): preservation; Preferably, step (5A) includes: The product from step (4) is cooled to 2-6℃ and refrigerated for about 12-24 hours to mature. or, Demulsify the product from step (4) and cool it to 20-25°C, then fill it into containers and refrigerate it at 2-6°C for approximately 12-24 hours to ripen; or, The product from step (4) is homogenized and then filled into containers. The homogenization pressure is 0-10 MPa and the homogenization temperature is ≤20℃.

12. The dairy product of claim 6 or the method of any one of claims 7-10, further comprising: (5B) Prepare the diluent; (6) Mix the product from step (4) with the diluent.

13. The dairy product of claim 6 or the method of claim 12, wherein, Step (5B) includes: 5B.1) Mix one or more of the following ingredients: sweetener, stabilizer, flavoring, acidity regulator, fat, protein, water, dietary fiber, complex nutrients, fruit and vegetable juice, and salt. 5B.2) Sterilize the product from step 5B.1) to obtain a diluted solution; Preferably, the stirring time is 30-40 minutes; Preferably, the sterilization is pasteurization; Preferably, the sterilization temperature is 95°C and the time is 300 seconds.

14. The dairy product of claim 6 or the method of claim 12 or 13, wherein, Step (6) includes: 6.1) Homogenize the product from step (4) to obtain milk base; 6.2) Mix the milk base with the diluent; Preferably, the milk base content is 20-75 wt% based on the total weight of the finished dairy product; Preferably, the homogenization temperature in step 6.1) is 20-30℃ and the pressure is 15-30MPa; Preferably, step 6.2) is followed by homogenization, preferably, the homogenization temperature is ≤20℃ and the pressure is 15-30MPa.

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