A modulated milk and a method for preparing the same

Abstract

The present application provides a kind of modulated milk and its preparation method, the raw material of the modulated milk includes: after protein deamidase enzymolysis cow milk;Wherein, the addition amount of protein deamidase is 0.3-1 ‰ by weight of the modulated milk;Enzymolysis temperature is 50-55 ℃, and enzymolysis time is 0.5-2.5 h.The present application is a kind of clean formula modulated milk, without additive, can effectively reduce the bitter taste caused by coffee in modulated milk, rich flavor, while product stability is good, can extend the shelf life of product, and there is no flocculation, delamination, precipitation and other phenomena appear in shelf life, greatly reduce the phenomenon of fat floating and coffee residue precipitation, and in high temperature sterilization process can reduce paste tube, improve the equipment operation efficiency, reduce the problem of product foreign matter and cleaning cost increase caused by paste tube.

Description

Technical Field

[0001] This invention relates to the field of dairy products, and more particularly to a liquid-modified dairy product and its preparation method. Background Technology

[0002] Flavored milk is a dairy product made primarily from at least 80% raw cow (or sheep) milk or reconstituted milk, with added ingredients such as sugar, flavorings, fruit juice, and food additives, processed through scientific proportioning. It caters to diverse consumer needs for taste and nutrition. Flavored milk not only retains the nutritional components of original milk but also enhances its nutritional value and taste experience by adding other elements such as vitamins and minerals. The market offers a wide variety of flavored milk products, including but not limited to fruit-flavored milk, coffee milk, and chocolate milk. These products are often popular with children and young consumers due to their rich and easily accepted flavors. Furthermore, flavored milk is a convenient option for fast-paced lifestyles, suitable as a breakfast drink or a daily energy booster.

[0003] The production process of flavored milk includes key steps such as raw material selection and pretreatment, ingredient mixing, homogenization and sterilization, filling and packaging. Each step requires precise control to ensure product quality and safety. Through these processes, flavored milk can maintain a longer shelf life while retaining its unique taste and nutritional value.

[0004] With increasing health awareness and focus on food safety, clean-label products are gaining popularity. Businesses are responding to this demand by reducing the use of chemical additives, optimizing formulations, and adopting more natural materials and methods to attract health-conscious consumers. Offering clean-label products not only helps businesses build consumer trust but also enhances brand image and market competitiveness. Consumer acceptance and purchasing enthusiasm for clean-label products have shown a significant upward trend recently. Clean-label products are those whose packaging clearly indicates information such as ingredients, environmental friendliness, and health and safety. This labeling helps consumers better understand the raw materials and performance of products, enabling them to make more informed purchasing decisions. As people pay more attention to health and environmental issues, health awareness is also rising. More and more consumers are concerned about the chemicals used in products and their impact on health. Clean-label products provide more information on ingredients and safety, meeting consumers' needs for health and safety. Increased consumer environmental awareness has also driven the development of the clean-label product market. These products typically use environmentally friendly materials, adopt sustainable production methods, and include relevant information on the packaging, allowing consumers to choose more environmentally friendly and sustainable products. Modern consumers place greater emphasis on transparency and credibility. Clean labels provide more information, enabling consumers to better understand a product's origin, manufacturing process, and ingredients, thereby building trust in the product. As the clean label market grows, more and more brands are launching clean label product lines to meet consumer demand.

[0005] Overall, consumer acceptance and purchasing enthusiasm for clean label products continues to grow. Health awareness, environmental awareness, the need for transparency, and increased market competition are driving this trend. Over time, the clean label product market is expected to continue expanding and become one of the main considerations in consumer purchasing decisions.

[0006] Commercially available fruit-flavored milk, coffee milk, and chocolate milk typically contain a certain proportion of fruit juice or fruit concentrate, coffee concentrate, and chocolate powder. Specific formulas vary by brand, but generally include: Base milk: usually made with whole or skim milk. Fruit juice or fruit concentrate / coffee concentrate: such as apple, strawberry, blueberry, etc., to enhance natural fruit and coffee flavors. Sugar: used to adjust sweetness; can be granulated sugar, fructose, etc. Stabilizers and emulsifiers: such as carrageenan and pectin, used to maintain the stability and texture of the dairy product. Flavorings: small amounts of natural or artificial flavorings may be added to enhance the flavor. Different brands and manufacturers may adjust the formula according to their own product characteristics and consumer preferences.

[0007] Flavored milk products, such as coffee milk, may exhibit sensory phenomena such as fat rising to the surface and coffee grounds settling during their shelf life. This fat adheres to the packaging walls, forming a ring of white fat, while black sediment forms at the bottom of the packaging. This phenomenon is more pronounced if the milk has high physicochemical properties; the coffee grounds are difficult to dissolve when shaken inverted, negatively impacting the product's appearance and providing a poor consumer experience. Furthermore, the taste of flavored milk products changes over time, affecting their sensory appeal and overall quality. Secondly, high-temperature sterilization of flavored milk products can cause flocculation and sedimentation, leading to clogged tubes, reduced equipment efficiency, and waste residue in the final product. Currently, consumers also demand clean labeling for RTD (Reliable Tolerance) products; adding stabilizers and acidity regulators to these products can erode consumer confidence. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a modulated milk and its preparation method.

[0009] To achieve the above objectives, the present invention provides a modified milk, the raw materials of which include: milk after enzymatic hydrolysis by protein deamidase; wherein, based on the weight of the modified milk, the amount of protein deamidase added is 0.3-1‰; the hydrolysis temperature is 50-55℃, and the hydrolysis time is 0.5-2.5h.

[0010] According to a specific embodiment of the present invention, preferably, the raw materials of the modified milk, by weight, include: 80-99 parts of milk after enzymatic hydrolysis by protein deamidase and 1-20 parts of flavoring agent.

[0011] According to a specific embodiment of the present invention, preferably, the raw materials of the modified milk, by weight, include: 89-93 parts of milk after protein deamidase hydrolysis and 7-11 parts of flavoring agent.

[0012] According to a specific embodiment of the present invention, preferably, the flavoring material includes one or more of coffee ingredients, sauce ingredients, and chocolate.

[0013] According to a specific embodiment of the present invention, preferably, the flavoring material comprises, by weight, one or more of the following: 1-9 parts coffee raw material, 1-9 parts sauce raw material, and 1-5 parts chocolate.

[0014] According to a specific embodiment of the present invention, preferably, the milk includes one or a combination of two or more of whole milk, skim milk, raw milk ultrafiltration retentate, and raw milk nanofiltration retentate.

[0015] According to a specific embodiment of the present invention, preferably, the milk is obtained by purifying raw milk.

[0016] According to a specific embodiment of the present invention, preferably, the step of purifying the milk includes filtering and centrifuging to remove impurities; more preferably, the mesh size of the filter is 80-600 mesh; even more preferably, the temperature conditions for centrifugation are 2-10℃ and the rotation speed is 4000-6000 rpm.

[0017] According to a specific embodiment of the present invention, preferably, the ultrafiltration membrane used to prepare the raw milk ultrafiltration retentate has a molecular weight cutoff of 5000-8000 Daltons, and the ultrafiltration temperature is 2-6℃.

[0018] According to a specific embodiment of the present invention, preferably, the nanofiltration membrane used to prepare the raw milk nanofiltration retentate has a molecular weight cutoff of 200-800MW, a nanofiltration temperature of 4-15℃, and a membrane pressure of 2-6bar.

[0019] According to a specific embodiment of the present invention, preferably, the coffee raw materials include one or more of coffee concentrate, coffee powder, and coffee extract.

[0020] According to a specific embodiment of the present invention, preferably, the coffee concentrate contains 15-20 Brix of soluble coffee solids.

[0021] According to a specific embodiment of the present invention, preferably, the chocolate comprises chocolate powder and / or chocolate flakes.

[0022] According to a specific embodiment of the present invention, preferably, the sauce ingredients include one or more of fruit juice, jam and flavored sauce.

[0023] According to a specific embodiment of the present invention, preferably, the raw material sources of the juice or jam include one or more combinations of strawberries, bananas, blueberries, white peaches, honeydew melons, pineapples, and mangoes.

[0024] According to a specific embodiment of the present invention, preferably, the flavor sauce includes one or more of apple flavor sauce, vanilla flavor sauce, and caramel flavor sauce.

[0025] On the other hand, the present invention also provides a method for preparing the above-mentioned modified milk, wherein the preparation method includes:

[0026] The modified milk is obtained by mixing enzymatically hydrolyzed milk and flavorings, homogenizing, and sterilizing.

[0027] In the above preparation method, preferably, the homogenization temperature is 50-65℃ and the homogenization pressure is 30 / 170bar-230bar, so as to further improve the stability and flavor of the product.

[0028] In the above preparation method, preferably, the sterilization is pasteurization, ultrapasteurization, or ultra-high temperature instantaneous sterilization.

[0029] In the above preparation method, preferably, the sterilization temperature is 72-140℃ and the sterilization time is 4-300s.

[0030] In the above preparation method, preferably, the sterilization temperature is 72-159℃ and the sterilization time is 0.09-300s; more preferably, the sterilization temperature is 130-159℃ and the sterilization time is 0.09-10s.

[0031] In the above preparation method, preferably, the preparation method further includes the steps of cooling and filling the modified milk obtained after sterilization; more preferably, the cooling temperature is 15-25℃; more preferably, the filling is aseptic filling.

[0032] According to a specific embodiment of the present invention, preferably, the preparation method includes:

[0033] (1) Test the physicochemical properties of raw milk to obtain qualified raw milk;

[0034] (2) Clean the qualified raw milk, remove impurities from the milk, and then perform ultrafiltration or nanofiltration to obtain the treated milk;

[0035] (3) Add protein deamidase to the treated raw milk and enzymatically hydrolyze it in a water bath at 50-55℃ for 1 hour to obtain enzymatically hydrolyzed milk.

[0036] (4) Mix the enzymatically hydrolyzed milk and flavorings to obtain a mixed liquid;

[0037] (5) The mixture is homogenized, sterilized, cooled and aseptically filled to obtain the modified milk.

[0038] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0039] According to a specific embodiment of the present invention, preferably, the preparation method includes:

[0040] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0041] Raw milk undergoes cold purification by filtering through an 80-600 mesh sieve to remove impurities. It is then centrifuged at 4000-6000 rpm under controlled conditions of 2-10℃ to further remove impurities. The ultrafiltration membrane used has a pore size of 5000-8000 Daltons, and the filtration temperature is 2-6℃.

[0042] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase in a water bath at 50-55°C for 0.5-2.5 hours to obtain hydrolyzed milk; the amount of E014 protein deamidase added was 0.3-1‰ based on the weight of the modified milk.

[0043] (3) Add 80-99 parts of enzymatically hydrolyzed milk and 1-20 parts of flavoring to prepare a mixed liquid.

[0044] (4) Homogenize the mixture at 50-65℃ and 30 / 180 bar, sterilize at 130-159℃ for 0.09-10s, cool to 15-20℃ and aseptically fill to obtain the modified milk.

[0045] This invention provides a clean formula milk and its preparation method. The resulting product requires no additional additives. Through protein deamidase treatment, the bitterness of coffee in the milk can be effectively reduced, enriching the flavor. The product also exhibits good stability, extending its shelf life. During this shelf life, there are no phenomena such as flocculation, stratification, or sedimentation, significantly reducing fat floating and coffee grounds settling. Furthermore, the high-temperature sterilization process greatly reduces tube clogging, improving equipment operating efficiency and reducing foreign matter issues and increased cleaning costs caused by tube clogging.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] (1) This invention uses protein deamidase as a processing aid to improve the sour taste, unstable system, fat floating, flocculation, layering, and precipitation in modified dairy products, and can extend shelf life and improve product quality. It also has the advantages of reducing production costs and improving equipment operating efficiency.

[0048] (2) Currently, all RTD-prepared milk products sold on the market contain stabilizers or acidity regulators. However, this invention provides a completely clean label formula prepared milk and its preparation method. By combining raw milk, coffee concentrate, protein deamidase, jam or juice, and chocolate, the protein deamidase is used to improve the taste and structure of the milk. Then, coffee concentrate is added to obtain a flavorful and smooth prepared milk product, which can improve the shelf life and quality of the product. The prepared milk prepared by this invention has healthier product attributes compared with products that contain added gums, dextrin, sugar esters and other sugar derivatives, sodium bicarbonate, dipotassium hydrogen phosphate, starch, stearate and stabilizers.

[0049] (3) The modified milk and its preparation method of the present invention have the advantages of reducing production costs and improving equipment operating efficiency when applied in industrial production. The preparation process of the present invention is simple, easy to operate, and suitable for industrial production and market promotion. Detailed Implementation

[0050] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0051] In actual production, those skilled in the art will understand that, provided that qualified products can be obtained, some related process steps can be adjusted or added or subtracted.

[0052] In this invention, the selection and acceptance of raw milk includes: selecting healthy dairy cows from large-scale dairy farms, and using mechanized milking equipment to extract fresh milk from the udders of these healthy cows. The raw milk is tested for protein, fat, non-fat milk solids, acidity, pH value, and total bacterial count. The acceptance standards comply with the national standard GB19301 "Raw Milk," and qualified raw milk is stored in a cold chain at 2-6℃.

[0053] Example 1

[0054] This embodiment provides a modulated milk and its preparation method:

[0055] The specific steps are as follows:

[0056] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0057] Raw milk undergoes cold purification by filtering through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0058] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0059] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase (from Qingrui Company) in a water bath at 55°C for 1 hour to obtain the hydrolyzed milk; the amount of E014 protein deamidase added was 0.5‰ based on the weight of the modified milk.

[0060] (3) Add 91 parts of enzymatically hydrolyzed milk and 9 parts of coffee concentrate to obtain a mixed liquid.

[0061] (4) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0062] Example 2

[0063] This embodiment provides a modulated milk and its preparation method:

[0064] The specific steps are as follows:

[0065] (1) Skim milk was treated with E014 protein deamidase by enzymatic hydrolysis in a water bath at 55°C for 1 hour; the amount of E014 protein deamidase added was 0.4‰ based on the weight of the modified milk.

[0066] (2) Add 91 parts of enzymatically hydrolyzed milk, 5 parts of coffee concentrate, and 4 parts of apple flavored sauce to obtain a mixed liquid.

[0067] (3) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0068] Example 3

[0069] This embodiment provides a modulated milk and its preparation method:

[0070] The specific steps are as follows:

[0071] (1) Whole milk was treated with E014 protein deamidase and enzymatically hydrolyzed in a water bath at 55°C for 1 hour; the amount of E014 protein deamidase added was 0.6‰ based on the weight of the modified milk.

[0072] (2) Add 90 parts of enzymatically hydrolyzed milk, 5 parts of coffee concentrate, and 5 parts of chocolate powder to make a mixed liquid.

[0073] (3) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0074] Example 4

[0075] This embodiment provides a modulated milk and its preparation method:

[0076] The specific steps are as follows:

[0077] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0078] Raw milk undergoes cold purification by filtering it through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0079] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0080] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase in a water bath at 55°C for 1 hour to obtain hydrolyzed milk; the amount of E014 protein deamidase added was 0.6‰ based on the weight of the modified milk.

[0081] (3) Add 93 parts of enzymatically hydrolyzed milk and 7 parts of strawberry jam to make a mixed liquid.

[0082] (4) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0083] Example 5

[0084] This embodiment provides a modulated milk and its preparation method:

[0085] The specific steps are as follows:

[0086] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0087] Raw milk undergoes cold purification by filtering it through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0088] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0089] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase in a water bath at 55°C for 1 hour to obtain hydrolyzed milk; the amount of E014 protein deamidase added was 0.5‰ based on the weight of the modified milk.

[0090] (3) Add 89 parts of enzymatically hydrolyzed milk, 7 parts of coffee concentrate, and 4 parts of caramel sauce to make a mixed liquid.

[0091] (4) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0092] Example 6

[0093] This embodiment provides a modulated milk and its preparation method:

[0094] The specific steps are as follows:

[0095] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0096] Raw milk undergoes cold purification by filtering it through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0097] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0098] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase in a water bath at 55°C for 1 hour to obtain hydrolyzed milk; the amount of E014 protein deamidase added was 0.6‰ based on the weight of the modified milk.

[0099] (3) Add 92 parts of enzymatically hydrolyzed milk, 3 parts of strawberry jam, and 5 parts of chocolate powder to make a mixed liquid.

[0100] (4) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0101] Comparative Example 1

[0102] This comparative example provides a modulated milk and its preparation method:

[0103] The specific steps are as follows:

[0104] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0105] Raw milk undergoes cold purification by filtering it through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0106] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0107] (2) Mix 91 parts milk and 9 parts coffee concentrate to obtain a mixed liquid.

[0108] (3) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0109] Comparative Example 2

[0110] This comparative example provides a modulated milk and its preparation method:

[0111] The specific steps are as follows:

[0112] (1) The ingredients are prepared by adding 90 parts of skim milk, 5 parts of coffee concentrate, 4 parts of apple flavored sauce, and 1 part of compound stabilizer (containing mono- and diglycerides of fatty acids, monoglycerides of succinate, microcrystalline cellulose, sodium tripolyphosphate, dipotassium hydrogen phosphate, xanthan gum, sodium hexametaphosphate, and sodium carboxymethyl cellulose) to obtain a mixed liquid.

[0113] (2) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain modified milk.

[0114] Comparative Example 3

[0115] This comparative example provides a modulated milk and its preparation method:

[0116] The specific steps are as follows:

[0117] (1) Add 90 parts whole milk, 5 parts coffee concentrate, and 5 parts chocolate powder to make a mixture.

[0118] (2) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain modified milk.

[0119] Comparative Example 4

[0120] This comparative example provides a modulated milk and its preparation method:

[0121] The specific steps are as follows:

[0122] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0123] Raw milk undergoes cold purification by filtering through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0124] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0125] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase in a water bath at 55°C for 1 hour to obtain hydrolyzed milk; the amount of E014 protein deamidase added was 0.2‰ based on the weight of the modified milk.

[0126] (3) Add 93 parts of enzymatically hydrolyzed milk and 7 parts of strawberry jam to make a mixed liquid.

[0127] (4) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0128] Comparative Example 5

[0129] This comparative example provides a modulated milk and its preparation method:

[0130] The specific steps are as follows:

[0131] (1) Test the physicochemical properties of raw milk, and use separation technology to purify the raw milk that passes the test to remove impurities; then perform ultrafiltration to obtain the treated milk; the steps are as follows:

[0132] Raw milk undergoes cold purification by filtering it through a 100-mesh sieve to remove impurities. It is then centrifuged at 4600 rpm under controlled conditions of 5-6℃ to remove further impurities.

[0133] The ultrafiltration membrane used has a pore size of 6000 Daltons; the filtration temperature of the ultrafiltration membrane is 4-6℃.

[0134] (2) The treated milk was enzymatically hydrolyzed using E014 protein deamidase in a water bath at 55°C for 1 hour to obtain hydrolyzed milk; the amount of E014 protein deamidase added was 0.1‰ based on the weight of the modified milk.

[0135] (3) Add 89 parts of enzymatically hydrolyzed milk, 7 parts of coffee concentrate, and 4 parts of caramel sauce to make a mixed liquid.

[0136] (4) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain the modified milk.

[0137] Comparative Example 6

[0138] This comparative example provides a modulated milk and its preparation method:

[0139] The specific steps are as follows:

[0140] (1) Add 92 parts skim milk, 3 parts vanilla sauce, and 5 parts chocolate powder to make a mixed liquid.

[0141] (2) The mixture is homogenized at 55±1℃ and 30 / 180 bar, sterilized at 159℃ for 0.09s, cooled to 15-20℃ and aseptically filled to obtain modified milk.

[0142] Experimental Results and Analysis:

[0143] I. Sensory Evaluation of Products

[0144] To better illustrate the beneficial effects of the present invention, sensory evaluation was conducted on the modified milk products of Examples 1-6 and Comparative Examples 1-6. 15g of each product was taken for sensory evaluation. Sensory evaluation was conducted by 20 professionals (10 men and 10 women), following the scoring criteria specified in Table 1. The final average score was taken. The sensory evaluation test results are shown in Table 2.

[0145] Table 1 Sensory Evaluation Criteria

[0146]

[0147] Table 2 Sensory Evaluation Scores

[0148]

[0149]

[0150] As can be seen from the above experimental results, compared with Comparative Examples 1-6, the overall likability of Examples 1-6 is better than that of Comparative Examples 1-6. The above sensory evaluation shows that the modified milk prepared by the present invention has good stability, almost no precipitation, and at the same time, the coffee and chocolate flavors are mellow, the vanilla caramel flavor and other flavor components are pure and healthy, the taste is full and thick, without obvious rough grains, with a light milky aroma, and the combination is harmonious, giving the product a full, rich and smooth taste.

[0151] Compared to Comparative Example 1 and Examples 1-6, the sensory evaluation scores of milk hydrolyzed with E014 protein deamidase were all lower than those of the examples when untreated milk was used instead of milk hydrolyzed with E014 protein deamidase, indicating that adding E014 protein deamidase can significantly improve the flavor of the modified milk. Compared to Comparative Example 2, adding E014 protein deamidase to the modified milk in Examples 1-6 can significantly improve the stability of the product system, and the overall performance is better than adding compound stabilizers, achieving the effects of clean labeling and health attributes. Compared to Comparative Examples 2, 3, and 6, adding E014 protein deamidase can also significantly improve the sensory properties of skimmed or whole milk products in Examples 2 and 3. Compared to Comparative Examples 4 and 5, it can be seen that lower concentrations of E014 protein deamidase outside the scope of this invention do not improve the flavor and texture of the product.

[0152] II. Product Stability Evaluation

[0153] Product stability was tested using a Lumisizer stability analyzer (2000 rpm / min, 25°C) for 4 hours, with the instability coefficient used as the evaluation index. pH was measured using a pH meter.

[0154] Table 3 Product stability evaluation and pH test data

[0155]

[0156]

[0157] The instability coefficient is essentially an evaluation of the uniformity of the product during centrifugation. A larger coefficient indicates greater instability. Table 3 shows that, based on Examples 1-6 and Comparative Example 2, the addition of E014 protein deamidase to raw milk treatment achieves or even surpasses the effect of adding a stabilizer, ensuring system stability and maintaining a relatively neutral environment. Examples 1-6 and Comparative Examples 1, 3, and 6 show that the product without added E014 protein deamidase exhibits poor stability. Examples 1-6 and Comparative Examples 4 and 5 show that the product with lower levels of added E014 protein deamidase exhibits poor stability.

[0158] III. Operating Efficiency of UHT Equipment

[0159] UHT equipment is used to sterilize products at 138±2℃. The need to stop the equipment for cleaning is determined based on the temperature difference of 8℃ that the equipment reaches during normal operation in the factory.

[0160] Table 4. Evaluation of the UHT sterilization stability of the product

[0161] product Runtime / hour Cleaning / hour Example 1 8.7 2 Example 2 8.9 2 Example 3 9.2 2 Example 4 9.5 2 Example 5 8.8 2 Example 6 9.0 2 Comparative Example 1 2.7 2 Comparative Example 2 6.9 2 Comparative Example 3 2.5 2 Comparative Example 4 4.8 2 Comparative Example 5 4.2 2 Comparative Example 6 3.5 2

[0162] Equipment operating efficiency directly impacts factory production costs and on-time product delivery. The effect of adding E014 protein deamidase was evaluated based on the operating time of the UHT equipment. Table 4 shows that, compared to Comparative Example 2, Examples 1-6, after treating raw milk with E014 protein deamidase, achieved or even surpassed the effect of adding a stabilizer, ensuring system stability and a longer equipment operating time. Examples 1-6 and Comparative Examples 1, 3, and 6 show that the product without added E014 protein deamidase had a shorter equipment operating time. Examples 1-6 and Comparative Examples 4 and 5 show that the product with a lower amount of E014 protein deamidase had a shorter equipment operating time.

[0163] This invention improves the taste of flavored milk by treating it with a specific proportion of E014 protein deamidase, resulting in a richer flavor and better product quality. Experimental verification revealed that adding 0.3-0.6‰ of the protein deamidase yields the best results; proportions below 0.3‰ do not achieve the desired improvement in flavor and quality.

[0164] This invention utilizes protein deamidase to process milk, adding coffee concentrate, chocolate powder or flakes, strawberry or banana jam, or vanilla caramel sauce to significantly enhance the flavor of the modified milk product. It also ensures product stability throughout its shelf life, greatly reducing fat bubbling and coffee grounds sedimentation. Furthermore, the high-temperature sterilization process during preparation significantly reduces tube clogging, improving equipment operating efficiency and minimizing foreign matter issues and increased cleaning costs caused by tube clogging.

Claims

1. A type of modified milk, wherein, The raw materials for the modified milk include: milk hydrolyzed by protein deamidase; wherein, based on the weight of the modified milk, the amount of protein deamidase added is 0.3-1‰; the hydrolysis temperature is 50-55℃, and the hydrolysis time is 0.5-2.5h.

2. The modified milk according to claim 1, wherein, The ingredients of the modified milk, by weight, include: 80-99 parts of milk hydrolyzed by protein deamidase and 1-20 parts of flavoring agent.

3. The modified milk according to claim 2, wherein, The flavorings include one or more of coffee ingredients, sauce ingredients, and chocolate.

4. The modified milk according to claim 2, wherein, By weight, the flavoring material comprises one or more of the following: 1-9 parts coffee ingredients, 1-9 parts sauce ingredients, and 1-5 parts chocolate.

5. The modified milk according to claim 1, wherein, The milk includes one or more of the following: whole milk, skim milk, raw milk ultrafiltration retentate, and raw milk nanofiltration retentate; Preferably, the ultrafiltration membrane used to prepare the raw milk ultrafiltration retentate has a molecular weight cutoff of 5000-8000 Daltons, and the ultrafiltration temperature is 2-6℃. Preferably, the nanofiltration membrane used to prepare the raw milk nanofiltration retentate has a molecular weight cutoff of 200-800MW, a nanofiltration temperature of 4-15℃, and a membrane pressure of 2-6bar.

6. The modified milk according to claim 3 or 4, wherein, The coffee raw materials include one or more of the following: coffee concentrate, coffee powder, and coffee extract. Preferably, the coffee concentrate contains 15-20 Brix of soluble coffee solids.

7. The modified milk according to claim 3 or 4, wherein, The sauce ingredients include one or more of the following: fruit juice, jam, and flavored sauce.

8. A method for preparing a modified milk according to any one of claims 1-7, wherein, The preparation method includes: The modified milk is obtained by mixing enzymatically hydrolyzed milk and flavorings, homogenizing, and sterilizing.

9. The preparation method according to claim 8, wherein, The homogenization process is carried out at a temperature of 50-65°C and a homogenization pressure of 30 / 170-230 bar.

10. The preparation method according to claim 8, wherein, The sterilization temperature is 72-159℃, and the sterilization time is 0.09-300s.

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