High-protein normal-temperature yoghurt and preparation method thereof

Abstract

The invention relates to the technical field of normal-temperature yoghurt, in particular to high-protein normal-temperature yoghurt and a preparation method thereof. The high-protein normal-temperature yoghourt comprises the following components in percentage by mass: 3-8% of protein powder, 0.3-2% of a stabilizer, 1-5% of a taste raw material, 6-8% of a sweetening agent and the balance of concentrated milk, wherein the protein powder is micronized whey protein powder and concentrated milk protein powder; the protein content of the high-protein normal-temperature yoghourt is not less than 6%, and the fat content is not less than 5%. The high-protein normal-temperature yoghurt provided by the invention is fine and smooth in mouth feel, does not have unpleasant flavor generated by independently adding milk powder, is suitable for people with high-protein nutritional requirements, also improves the protein and fat contents, and ensures the texture stability and good mouth feel expression of the product in the normal-temperature shelf life.

Description

Technical Field

[0001] This invention relates to the field of room temperature yogurt technology, and in particular to a high-protein room temperature yogurt and its preparation method. Background Technology

[0002] Yogurt, a product that combines delicious taste with high nutritional value, offers numerous nutritional and health benefits and is widely loved. As people's living standards improve, their nutritional requirements for dairy products are also increasing. High-protein yogurt contains more protein than regular yogurt, combining the prebiotic effects of fermented milk with the nutritional and health benefits of high protein, playing an important physiological role in maintaining human health and enhancing immunity.

[0003] Currently, increasing the protein content of yogurt is mainly achieved through post-fermentation concentration. This involves filtering or centrifuging to concentrate a certain volume of acidic whey after fermentation, thereby increasing the protein content of the yogurt. However, this method has some drawbacks. Firstly, it requires additional concentration equipment, increasing production costs. Secondly, it produces a large amount of acidic whey, which, if directly discharged, would cause environmental pollution, and further processing would also increase production costs. Furthermore, the discharged whey contains whey protein, calcium, fermentation metabolites, and other nutrients and flavor substances, leading to a loss of nutritional value and taste in the yogurt.

[0004] However, the high protein content of yogurt can also be achieved by adding protein powder to the fermentation base before fermentation. Commonly used protein powders include whole milk powder, skim milk powder, whey protein, and sodium caseinate. For example, patent application number 202211671908.6 provides a high-protein fermented milk and its preparation method, which increases the protein content of the product by using concentrated whey protein powder alone. Although this avoids the discharge of acidic whey, conventional protein powder addition can lead to unpleasant sensory problems in yogurt, such as a grainy texture, a noticeable powdery taste, and a rough mouthfeel. For example, patent application number 202111383047.7 provides a high-protein fermented milk and its preparation method, which increases the proportion of whey protein in yogurt by adding whey protein powder, adjusting the proportion of whey protein from 20% to 40%~50%, thus achieving the goal of being rich in whey protein and increasing the total protein content of the yogurt. However, one of the drawbacks of simply increasing the protein content of yogurt by adding whey protein is that an excessively high proportion of whey protein can exacerbate whey separation in the yogurt, resulting in unstable product shelf life. For example, patent application number 202311692087.9 provides a low-fat, high-protein fermented milk and its preparation method. This method involves separating whey protein from skim milk, then micronizing it through shearing and refilling to increase the product's protein content. However, this method is complex and requires additional production equipment. Furthermore, supplementing protein content solely with whey protein only results in a limited increase in protein levels and cannot guarantee stable quality over a long shelf life. Producing high-protein yogurt requires considering not only performance indicators, flavor, texture, nutrition, and stability, but also simplifying the production process and reducing costs. There is an urgent need in this field to provide a new high-protein room-temperature yogurt and its preparation method that overcomes the drawbacks of current methods that rely on post-fermentation concentration to achieve high protein levels, and to overcome the technical challenges in improving the taste, texture, and stability of room-temperature high-protein yogurt. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a high-protein room-temperature yogurt and its preparation method. By carefully selecting the composition and ratio of protein raw materials, establishing a stable system, and optimizing the fermentation process, this invention overcomes the shortcomings of existing technologies, enabling room-temperature yogurt products to meet high-quality standards under high protein requirements. This invention not only achieves high protein content (protein content ≥ 6%) in yogurt products, but also significantly improves the flavor, texture, and stability of high-protein yogurt during a 5-month shelf life at room temperature, effectively reducing the pasty texture, grainy feel, and protein powder taste of high-protein yogurt.

[0006] Firstly, the high-protein room-temperature yogurt provided by this invention comprises, by weight percentage: 3%~8% protein powder, 0.3%~2% stabilizer, 1%~5% flavoring ingredients, 6%~8% sweetener, and the remainder being concentrated milk; wherein the protein powder is micronized whey protein powder and concentrated milk protein powder; the high-protein room-temperature yogurt has a protein content ≥6% and a fat content ≥5%. This invention provides a high-protein room-temperature yogurt with a protein content ≥6% and a fat content ≥5%. This high-protein room-temperature yogurt not only has a delicate and smooth texture but also avoids the unpleasant flavor caused by the addition of milk powder alone. Furthermore, as a room-temperature product, it is suitable for people seeking high-protein nutrition. This invention standardizes and concentrates raw milk into concentrated milk with the above-mentioned content, and combines it with a design that uses micronized whey protein and concentrated milk protein to rationally allocate the ratio of whey protein to casein based on the concentrated milk, so that the protein content in the product can reach 6%~16%. Meanwhile, by adding fatty ingredients, the fat content of high-protein yogurt is increased, resulting in a smooth and delicate texture and good flavor. Combined with stabilizers and ingredient ratios, the product's textural stability and better taste can be achieved during its shelf life at room temperature.

[0007] Preferably, the high-protein room-temperature yogurt has a protein content of 6% to 16%, more preferably 6% to 12%, and a fat content of 5% to 8%, more preferably 5% to 6%.

[0008] Preferably, the ratio of the micronized whey protein powder to the concentrated milk protein powder is 1:1 to 4:1 based on the mass of protein. For example, this ratio can be 4:1, 7.5:2.5, 2:1, 3:2, 4:3, 8:5, 7:3, 1:1, etc., as well as any ratio between them.

[0009] Further preferably, the protein content of the micronized whey protein powder is 40%~80%; and / or, the protein content of the concentrated milk protein powder is 60%~80%; and / or, the particle size of the selected micronized whey protein powder is ≤5µm.

[0010] Preferably, the ratio of the concentrated milk to the protein powder is 1:1 to 3:1 based on the mass of protein. For example, the ratio can be 3:1, 7:3, 2:1, 3:2, 4:3, 8:5, 1:1, etc., as well as any ratio between them.

[0011] Preferably, the stabilizer is physical starch, seaweed powder, gelatin, and pectin. Preferably, the mass ratio of the physical starch, seaweed powder, gelatin, and pectin is 3~10:1~5:2~8:0.5~3. This invention increases the fat content of high-protein yogurt by adding fatty ingredients, resulting in a smooth and delicate texture and good flavor. Combined with specific types and key ratios of stabilizers, it perfectly achieves textural stability and good taste during the shelf life at room temperature, better solving the problems of protein precipitation and water separation in high-protein yogurt products.

[0012] Further preferably, the mass ratio of the physical starch, the seaweed powder, the gelatin, and the pectin is 4~5:1.5~3:2~3:1.5~2. In the high-protein room-temperature yogurt, the physical starch is 0.3%~1%, the seaweed powder is 0.1%~0.5%, the gelatin is 0.2%~0.8%, and the pectin is 0.05%~0.3%. Preferably, the physical starch is 0.4%~0.5%, the seaweed powder is 0.15%~0.3%, the gelatin is 0.2%~0.3%, and the pectin is 0.15%~0.2%; preferably, the physical starch is glutinous rice starch or tapioca starch.

[0013] Preferably, the flavoring ingredient is selected from one or more of light cream, anhydrous butter, cream cheese, and cheese powder. Using preferred fatty ingredients as flavoring ingredients in this invention achieves better results.

[0014] Further preferably, the flavoring ingredient is light cream or anhydrous butter.

[0015] Further preferably, the sweetener is white sugar.

[0016] Further preferably, the concentrated milk has a protein content of ≥4.0% and a fat content of ≥3.5%.

[0017] The high-protein, room-temperature yogurt provided by this invention not only has a delicate and smooth texture but also avoids the unpleasant flavor associated with the addition of milk powder alone. Being a room-temperature product, it is suitable for consumers seeking high-protein nutrition. This invention standardizes and concentrates raw milk into the aforementioned concentrated milk content, combining it with exogenous protein powder added to the feed solution. This results in a protein content of 6% to 16% or higher in the product. This improves the utilization rate of milk solids and avoids the formation of acidic whey, making it an environmentally friendly production method. This invention designs a combination of micronized whey protein and concentrated milk protein, rationally distributing the whey protein and casein components based on the concentrated milk. This not only increases the product's protein requirements but also avoids the tendency of high-concentration whey protein to gel during the heat treatment of high-protein yogurt, which can easily cause equipment blockage and significantly reduce the yogurt's taste and quality. This invention, by designing the protein distribution ratio based on the provided protein content, significantly improves the taste and flavor of the high-protein yogurt, solving the problems of poor flavor and coarse texture in existing high-protein yogurts that are often produced by directly adding concentrated whey protein, skim milk powder, or using only a concentration process. This invention increases the fat content of high-protein yogurt by adding fatty ingredients, resulting in a smooth and delicate texture and excellent flavor. Combined with specific stabilizer types and key ratios, it perfectly achieves textural stability and good taste during the shelf life at room temperature. It also solves the problems of protein precipitation and water separation in high-protein yogurt products. The high-protein room-temperature yogurt and its preparation method of this invention utilize pre-concentration of raw milk + addition of exogenous proteins, screening of micronized whey protein and concentrated milk protein, and adjusting the composition ratio of fermented milk proteins, as well as the types and ratios of stabilizers. These technologies comprehensively address the common problems in high-protein room-temperature yogurt, such as thick texture, lack of smoothness, protein precipitation, water separation, and poor taste and flavor.

[0018] Secondly, the present invention provides a method for preparing the above-mentioned high-protein room-temperature yogurt, comprising the following steps: 1) Standardize the membrane treatment of raw milk to obtain concentrated milk.

[0019] 2) After heating the concentrated milk, add protein powder and stir to hydrate; then add sweetener, flavoring ingredients and stabilizer, and after mixing, homogenize, sterilize once and cool to obtain a mixed liquid.

[0020] 3) Add a starter culture to the mixture, and after fermentation, break the emulsion and cool it to obtain fermented yogurt.

[0021] 4) The fermented yogurt is sterilized a second time.

[0022] In this invention, the standardization mentioned is a conventional process in the field, which generally involves adjusting milk fat and milk protein to achieve the required nutritional indicators.

[0023] Preferably, in step 1), concentrated milk with protein ≥ 4.0 wt% and fat ≥ 3.5 wt% is obtained; and / or, the concentrated milk is further subjected to homogenization; preferably, the concentrated milk is preheated to 60~70°C, homogenized under a homogenization pressure of 150~200 bar, and then cooled to 25~40°C.

[0024] Further preferred, in step 2), the concentrated milk is heated to 45~55℃ and the stirring and hydration time is ≥30min; and / or, the temperature of the first sterilization is 115~131℃ and the time is 3~6s.

[0025] Further preferably, in step 3), the fermenting agent includes one or more of the following: *Lactobacillus delbrueckii* subsp. bulgaricus, *Streptococcus salivarius* subsp. thermophilus, *Bifidobacterium animalis* subsp. lactis, *Lactobacillus acidophilus*, *Lactococcus lactis* subsp. lactis, *Lactococcus fat*, *Lactobacillus helveticus*, *Lactobacillus rhamnosus*, and *Lactobacillus plantarum*. The strains selected in this invention exhibit rapid fermentation and low viscosity; the preferred strains, *Lactobacillus delbrueckii* subsp. bulgaricus, *Streptococcus salivarius* subsp. thermophilus, and one or more other optional strains, show the best results.

[0026] Further optimization involves fermentation at a temperature of 40-44°C, a fermentation time of 6-8 hours, and demulsification after fermentation to an acidity of 100-110°T.

[0027] Preferably, in step 4), the temperature of the secondary sterilization is 72~78℃ and the sterilization time is 20~30s; after the secondary sterilization, the product is cooled to below 25℃ before filling.

[0028] The beneficial effects of this invention are at least as follows: The high-protein room-temperature yogurt provided by this invention has a protein content of 6% to 16% or more and a fat content of ≥4%. This room-temperature yogurt has a delicate and smooth texture, without the unpleasant flavor caused by milk powder. Compared with commercially available high-protein room-temperature yogurts, it is more suitable for consumers who pursue high-protein nutrition. By combining concentrated raw milk with micronized whey protein and concentrated milk protein, not only is the formation of sour whey avoided, but the utilization rate of milk solids and protein content are also improved. The unique protein composition ratio design effectively solves the problem of high-concentration whey protein easily forming gels during heat treatment, thereby improving the taste and flavor. At the same time, the added fat ingredients and specific stabilizers further improve the quality of the yogurt while ensuring the textural stability and excellent taste of the product during its room-temperature shelf life, successfully overcoming the shortcomings of existing high-protein yogurts in terms of flavor and texture. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] Unless otherwise specified, all reagents and equipment used in the following examples are commercially available.

[0031] Unless otherwise specified, the methods described in the following embodiments can be implemented using conventional methods in the art.

[0032] Example 1

[0033] This embodiment provides a high-protein room-temperature yogurt and its preparation method.

[0034] The product formula for high-protein room-temperature yogurt provided in this embodiment is as follows: 84.45% concentrated milk, 7.5% white sugar, 3% micronized whey protein powder, 0.8% concentrated milk protein powder, 3% light cream, 0.5% glutinous rice starch, 0.3% gelatin, 0.3% seaweed powder, and 0.15% pectin.

[0035] Among them, the micronized whey protein powder has a protein content of 40% and a particle size of 4µm, while the concentrated milk protein powder has a protein content of 80%. The protein composition in the formula is concentrated milk protein: exogenous protein = 4:2, of which whey protein: milk protein = 2:1 in the exogenous protein composition.

[0036] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0037] The method for preparing high-protein room-temperature yogurt provided in this embodiment is as follows.

[0038] (1) Raw milk was standardized by membrane treatment to obtain concentrated milk with protein ≥5.0% and fat ≥4.5%. The concentrated milk was also homogenized by preheating it to 68°C and homogenizing it under a homogenization pressure of 180 bar. Then it was cooled to 25°C.

[0039] (2) Add concentrated milk into a mixing tank, heat it to 50°C, add micronized whey protein powder and concentrated milk protein powder under stirring conditions, stir and hydrate for more than 30 minutes, then add white sugar, physical starch, gelatin, seaweed powder, pectin and light cream, and circulate and stir for more than 15 minutes to make fermentation base.

[0040] (3) Preheat the fermentation substrate to 68°C, homogenize it at 180 bar, and then sterilize it at 121°C for 4 seconds. Then cool it to 42°C, and inoculate it with 200 DCU / ton of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus fermentation culture. Stir for 10 minutes and start fermentation for 6 hours. When the final acidity reaches 105°T, demulsification is performed. The demulsified fermented milk is smoothed using a smoothing pump and then cooled to 8°C.

[0041] (4) The cooled fermented milk is subjected to secondary sterilization treatment at a temperature of 75°C and a time of 20 seconds. After sterilization, it is cooled and filled.

[0042] The high-protein room-temperature yogurt prepared by the method provided in this embodiment has a protein content of 6.14% and a fat content of 5.03%.

[0043] Example 2

[0044] This embodiment provides a high-protein room-temperature yogurt and its preparation method.

[0045] The product formula for high-protein room-temperature yogurt provided in this embodiment is as follows: 80.95% concentrated milk, 7.5% white sugar, 4% micronized whey protein powder, 2.5% concentrated milk protein powder, 3.5% light cream, 0.4% glutinous rice starch, 0.3% gelatin, 0.2% seaweed powder, and 0.15% pectin.

[0046] Among them, the protein content of micronized whey protein powder is 70%, the particle size of micronized whey protein powder is 4um, and the protein content of concentrated milk protein powder is 80%; the protein composition of the formula is concentrated milk protein: exogenous protein = 1:1, of which the ratio of micronized whey protein to milk protein in the exogenous protein is 3:2.

[0047] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0048] The preparation method of high-protein room-temperature yogurt provided in this embodiment is the same as that in Example 1, except that the protein content of the concentrated milk obtained by standardization is 6%.

[0049] The high-protein room-temperature yogurt prepared by the method provided in this embodiment has a protein content of 10.23% and a fat content of 5.11%.

[0050] Example 3

[0051] This embodiment provides a high-protein room-temperature yogurt and its preparation method.

[0052] The product formula for high-protein room-temperature yogurt provided in this embodiment is as follows: 80.45% concentrated milk, 7.5% white sugar, 5% micronized whey protein powder, 5% concentrated milk protein powder, 1% anhydrous butter, 0.4% physical starch, 0.3% gelatin, 0.15% seaweed powder, and 0.2% pectin.

[0053] Among them, the protein content of micronized whey protein powder is 80%, the particle size of micronized whey protein powder is 5um, and the protein content of concentrated milk protein powder is 80%; the protein composition of the formula is concentrated milk protein: exogenous protein = 1:1, of which the ratio of micronized whey protein to milk protein in the exogenous protein is 1:1.

[0054] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0055] The preparation method of high-protein room-temperature yogurt provided in this embodiment is the same as that in Example 1, except that the protein content of the concentrated milk obtained by standardization is 9.0%.

[0056] The high-protein room-temperature yogurt prepared by the method provided in this embodiment has a protein content of 15.19% and a fat content of 5.09%.

[0057] Example 4

[0058] This embodiment provides a high-protein room-temperature yogurt and its preparation method.

[0059] The product formula for high-protein room-temperature yogurt provided in this embodiment is as follows: 87.95% concentrated milk, 6% white sugar, 2% micronized whey protein powder, 1% concentrated milk protein powder, 2% light cream, 0.3% physical starch, 0.2% gelatin, 0.5% seaweed powder, and 0.05% pectin.

[0060] Among them, the protein content of micronized whey protein powder is 40%, the particle size of micronized whey protein powder is 5um, and the protein content of concentrated milk protein powder is 60%; the protein composition of the formula is concentrated milk protein: exogenous protein = 7:3, of which the ratio of micronized whey protein to milk protein in the exogenous protein is 4:3.

[0061] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0062] The preparation method of high-protein room-temperature yogurt provided in this embodiment is the same as that in Example 1, except that the protein content of the concentrated milk obtained by standardization is 4.0%.

[0063] The high-protein room-temperature yogurt prepared by the method provided in this embodiment has a protein content of 5.02% and a fat content of 5.16%.

[0064] Example 5

[0065] This embodiment provides a high-protein room-temperature yogurt and its preparation method.

[0066] The product formula for high-protein room-temperature yogurt provided in this embodiment is as follows: 82.25% concentrated milk, 8% white sugar, 2% micronized whey protein powder, 1% concentrated milk protein powder, 5% light cream, 1% physical starch, 0.8% gelatin, 0.1% seaweed powder, and 0.05% pectin.

[0067] Among them, the protein content of micronized whey protein powder is 80%, the particle size of micronized whey protein powder is 5um, and the protein content of concentrated milk protein powder is 60%; the protein composition of the formula is concentrated milk protein: exogenous protein = 2:1, of which the ratio of micronized whey protein to milk protein in the exogenous protein is 8:3.

[0068] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0069] The preparation method of high-protein room-temperature yogurt provided in this embodiment has the same process flow as in Embodiment 1.

[0070] The high-protein room-temperature yogurt prepared by the method provided in this embodiment has a protein content of 6.18% and a fat content of 6.11%.

[0071] Example 6

[0072] This embodiment provides a high-protein room-temperature yogurt and its preparation method.

[0073] The product formula for high-protein room-temperature yogurt provided in this embodiment is as follows: 83.9% concentrated milk, 6% white sugar, 5% micronized whey protein powder, 3% concentrated milk protein powder, 1% anhydrous butter, 0.5% physical starch, 0.2% gelatin, 0.1% seaweed powder, and 0.3% pectin.

[0074] Among them, the protein content of micronized whey protein powder is 40%, the particle size of micronized whey protein powder is 5um, and the protein content of concentrated milk protein powder is 60%; the protein composition of the formula is concentrated milk protein: exogenous protein = 1:1, of which the ratio of micronized whey protein to milk protein in the exogenous protein is 1:1.

[0075] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0076] The preparation method of high-protein room-temperature yogurt provided in this embodiment has the same process flow as in Embodiment 1.

[0077] The high-protein room-temperature yogurt prepared by the method provided in this embodiment has a protein content of 8.05% and a fat content of 6.35%.

[0078] Comparative Example 1

[0079] This comparative example provides a high-protein room-temperature yogurt and its preparation method.

[0080] The formula for the high-protein room-temperature yogurt provided in this comparative example is as follows: 83.6% raw milk, 7.5% white sugar, 7% concentrated whey protein powder, 1% anhydrous butter, 0.5% physical starch, 0.3% gelatin, 0.3% seaweed powder, and 0.15% pectin.

[0081] Among them, the concentrated whey protein powder is a non-micronized whey protein powder with a protein content of 80%.

[0082] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0083] The preparation method of the high-protein room-temperature yogurt provided in this comparative example is the same as that in Example 1, except that the raw milk is not concentrated and the protein content is 3.1%.

[0084] The high-protein room-temperature yogurt prepared by the method provided in this comparative example has a protein content of 8.21% and a fat content of 4.65%.

[0085] Comparative Example 2

[0086] This comparative example provides a high-protein room-temperature yogurt and its preparation method.

[0087] The formula for the high-protein room-temperature yogurt provided in this comparative example is as follows: 89.6% raw milk, 7.5% white sugar, 1% concentrated whey protein powder, 1% anhydrous butter, 0.5% physical starch, 0.3% gelatin, 0.3% seaweed powder, and 0.15% pectin.

[0088] Among them, the concentrated whey protein powder is a non-micronized whey protein powder with a protein content of 80%.

[0089] The performance indicators of each raw material meet the conventional quality standards required in this field.

[0090] The preparation method of the high-protein room-temperature yogurt provided in this comparative example has the same process flow as in Example 1, but with the following differences: 1. The raw milk is not concentrated and has a protein content of 3.1%; 2. The raw milk, white sugar, and anhydrous butter are dissolved and mixed, sterilized to form a base material for fermentation, and after fermentation, the fermented milk is concentrated by filtration, with the protein content of the fermented milk reaching more than 8%; 3. The stabilizer raw materials are separately prepared into a colloidal base material, and the concentrated fermented milk and the colloidal base material are mixed evenly and then sterilized a second time.

[0091] The high-protein room-temperature yogurt prepared by the method provided in this comparative example has a protein content of 8.17% and a fat content of 4.52%.

[0092] Comparative Example 3

[0093] This comparative example provides a high-protein room-temperature yogurt and its preparation method.

[0094] The formula for the high-protein room-temperature yogurt provided in this comparative example is as follows: 85.58% concentrated milk, 7.5% white sugar, 3.5% micronized whey protein powder, 2% concentrated milk protein powder, 0.8% hydroxypropyl distarch phosphate, 0.3% gelatin, 0.12% pectin, and 0.2% agar.

[0095] Among them, the protein content of micronized whey protein powder is 80%, the particle size of micronized whey protein powder is 5um, and the protein content of concentrated milk protein powder is 60%; the protein composition of the formula is concentrated milk protein: exogenous protein = 1:1, of which the ratio of micronized whey protein to milk protein in the exogenous protein is 7:3.

[0096] The preparation method of the high-protein room-temperature yogurt provided in this comparative example has the same process flow as in Example 1.

[0097] The high-protein room-temperature yogurt prepared by the method provided in this comparative example has a protein content of 8.26% and a fat content of 4.7%.

[0098] The high-protein room-temperature yogurts obtained from the above examples and comparative examples were subjected to the following tests and evaluations.

[0099] (1) Physicochemical tests, sensory tests, viscosity tests, particle size tests, and centrifugal dehydration rate tests were conducted on the products in Examples 1-6 and Comparative Examples 1-3. Among them, the sensory test was conducted by a sensory evaluation group composed of 30 professional sensory evaluators, who comprehensively evaluated the color, texture, flavor, and taste, and selected descriptive words for description; the viscosity test method was to use an AntonPaar MCR302 rheometer; the particle size test was to use a Mastersizer 3000 Malvern particle size analyzer; the centrifugal dehydration rate test method was to weigh 20g of yogurt sample through a 25ml centrifuge tube, centrifuge at 3500 rpm / min for 15min, discard the supernatant, weigh the remaining yogurt, and calculate the centrifugal dehydration rate.

[0100] (2) Sensory evaluation and whey separation tests were conducted on the products of Examples 1-6 and Comparative Examples 1-3 during their shelf life. Sensory evaluation during shelf life involved comparing taste differences using 1-day samples as standards, and describing the differences in samples with significant variations. The whey separation test involved storing the fermented milk products prepared in the examples and comparative examples at room temperature for one month, cutting open the sample packaging, collecting the weight of the surface whey separated, and calculating the amount of surface whey separated from each sample. The overall evaluation results are shown in Table 1.

[0101]

[0102] Overall test and evaluation results show that the high-protein room-temperature yogurt provided in Examples 1-6 of this invention has significant differences compared to Comparative Examples 1-3. The examples not only have obvious advantages in texture, flavor, and mouthfeel, but also show no significant whey separation during shelf life. Furthermore, the yogurt obtained by using concentrated whey protein powder to increase protein content, such as in Comparative Example 2, has a rough texture, noticeable powdery and grainy feel, and a significantly increased amount of whey separation during shelf life, further verifying that the protein powder composition and protein ratio used in this invention have a significant impact on the mouthfeel and textural stability of the final high-protein yogurt. In addition, in terms of cost, the raw material and equipment costs of high-protein yogurt produced by the post-concentration method are much higher than those of the production method of this invention. In terms of production efficiency, when producing the same amount of product on the same production line, the time required by the post-concentration method is more than three times that of the method of this invention. In conclusion, the high-protein room-temperature yogurt provided by this invention is superior to similar products produced by the post-concentration method and the traditional external additive method in terms of texture, flavor, mouthfeel, and shelf life. The preparation method of the present invention has low production cost and high production efficiency, and is suitable for large-scale industrial production.

[0103] 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high protein ambient yogurt, characterized in that, The product comprises, by weight percentage: 3% to 8% protein powder, 0.3% to 2% stabilizer, 1% to 5% flavoring ingredients, 6% to 8% sweetener, and the remainder being concentrated milk; wherein the protein powder is micronized whey protein powder and concentrated milk protein powder; the high-protein room-temperature yogurt has a protein content ≥6% and a fat content ≥5%.

2. The high protein ambient yogurt of claim 1, characterized in that, The ratio of the micronized whey protein powder to the concentrated milk protein powder is 1:1 to 4:1, based on the mass of protein.

3. The high protein ambient yogurt of claim 2, characterized in that, The protein content of the micronized whey protein powder is 40% to 80%; and / or the protein content of the concentrated milk protein powder is 60% to 80%; and / or the particle size of the selected micronized whey protein powder is ≤5 μm.

4. The high protein ambient yogurt of any of claims 1-3, characterized in that, The ratio of the concentrated milk to the protein powder is 1:1 to 3:1, based on the mass of protein.

5. The high-protein room-temperature yogurt according to any one of claims 1-4, characterized in that, The stabilizers are physical starch, seaweed powder, gelatin, and pectin.

6. The high protein ambient yogurt of claim 5, characterized in that, The mass ratio of the physical starch, the seaweed powder, the gelatin, and the pectin is 3~10:1~5:2~8:0.5~3; and / or, the physical starch is glutinous rice starch or tapioca starch.

7. The high protein ambient yogurt of any of claims 1-6, characterized in that, The flavoring ingredients are selected from one or more of light cream, anhydrous butter, cream cheese, and cheese powder; and / or, the sweetener is granulated sugar; and / or, the concentrated milk has a protein content ≥4.0% and a fat content ≥3.5%.

8. Process for the preparation of the high-protein ambient yoghurt according to any one of claims 1 to 7, characterized in that, Includes the following steps: 1) Standardize raw milk through membrane processing to obtain concentrated milk; 2) After heating the concentrated milk, add protein powder and stir to hydrate; then add sweetener, flavoring ingredients and stabilizer, and after mixing, homogenize, sterilize once and cool to obtain a mixed liquid; 3) Add a starter culture to the mixture, and after fermentation, break the emulsion and cool it to obtain fermented yogurt; 4) The fermented yogurt is sterilized a second time.

9. The production method according to claim 8, characterized by, In step 1), concentrated milk with protein ≥ 4.0 wt% and fat ≥ 3.5 wt% is obtained; And / or, in step 2), the concentrated milk is heated to 45~55℃ and the stirring hydration time is ≥30min; And / or, the temperature for the first sterilization is 115~131℃, and the time is 3~6s.

10. The method of any one of claims 7-9, wherein, In step 3), the fermenting agent includes one or more of the following: Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus salivarius subsp. thermophilus, Bifidobacterium animalis subsp. lactis, Lactobacillus acidophilus, Lactococcus lactis subsp. lactis, Lactococcus fat, Lactobacillus helveticus, Lactobacillus rhamnosus, and Lactobacillus plantarum. And / or, the fermentation temperature is 40~44℃, the fermentation time is 6~8h, and the emulsion is broken after the acidity reaches 100~110°T; And / or, in step 4), the temperature of the secondary sterilization is 72~78℃ and the sterilization time is 20~30s; after the secondary sterilization, the temperature is cooled to below 25℃ for filling.

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