Sucrose-free low-GI yoghourt as well as preparation method and application thereof

Abstract

The invention provides sucrose-free low-GI yoghourt and a preparation method and application thereof.The sucrose-free low-GI yoghourt is prepared from, by weight, 5%-8% of D-psicose, 1%-3% of a white kidney bean extract, 0.5%-2% of a mulberry leaf extract, 0.002%-0.004% of a leavening agent, 0.006%-0.014% of stevioside and the balance water according to the total mass of yoghourt raw materials. And the balance of raw milk. According to the yogurt provided by the invention, the use of starch raw materials filled with solids commonly used in zero-sucrose yogurt in the prior art is avoided, so that the intake of glycemic carbohydrates is further reduced, and the yogurt better conforms to the characteristics of low-GI products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dairy product processing, in particular to a sucrose-free low GI yogurt and a preparation method and application thereof. BACKGROUND

[0002] With the continuous improvement of modern people's health consciousness and the increasing prevalence of lifestyle-related chronic diseases such as diabetes and obesity, the public is increasingly concerned about sugar intake in daily diet and its impact on blood sugar. This is mainly due to the deepening of consumers' understanding of the harm of "invisible sugar", and the low GI diet concept is widely accepted because it helps to stabilize blood sugar and control weight. Under this background, the demand for sucrose-free, low glycemic index (GI) yogurt has increased significantly, becoming an alternative to traditional formulations (yogurt containing white sugar).

[0003] To meet market demand, a variety of "sucrose-free" or "low GI" yogurts have emerged. These products in the prior art usually use a combination of high-potency sweeteners (such as steviol glycosides, mogroside, acesulfame, aspartame, etc.) and bulking sweeteners (such as erythritol, sorbitol, xylitol, etc.) to replace sucrose and provide sweetness. For example, patent CN 111728030 B discloses a sucrose-free yogurt with long shelf life at room temperature and improved immunity. The raw materials of the yogurt are replaced with sugar alcohols (bulking sweeteners) and sweeteners (high-potency sweeteners) and also added with starch; CN 107223709 A discloses a low-sugar or sucrose-free yogurt and a preparation method thereof. The raw materials of the yogurt are also replaced with sugar substitutes, i.e. natural sweeteners and bulking sweeteners, and also added with starch and other stabilizers; CN 114208883 A discloses a sucrose-free yogurt and a preparation method thereof. The raw materials of the yogurt contain sugar alcohols and high-potency sweeteners, as well as a combination of stabilizers including modified starch.

[0004] However, such prior art has many limitations: 1) the filling sweetener has defects in taste. Sugar alcohol filling sweeteners will produce a significant cooling sensation in the mouth, which is unnatural and unnatural in dairy products, and the product acceptance is low. 2) A series of problems caused by limited addition. When high-fold sweeteners and filling sweeteners are used instead of white sugar, the amount used is usually very small (the amount of white sugar in yogurt formula is usually 7-8%, and the amount of erythritol and other sweeteners is about 4%), which makes it almost impossible to increase the product viscosity. Although the "sugar source" problem is solved, in actual formula design, more carbohydrates-chemically modified / physical starches are often used to play a filling solid role, thereby increasing the yogurt viscosity, smoothness, and texture, and increasing the stability of the system. The yogurt product is only superficially "without sucrose", but does not meet the essence of 0 carbohydrates, low carbohydrates. 3) White sugar can well balance the sour taste in yogurt products, making the overall flavor round and harmonious. Filling sweeteners have poor functionality in suppressing sour taste, which can make the product more prominent or the overall flavor less harmonious; and the unpleasant aftertaste of the filling sweetener will interfere with the main flavor of the yogurt product, making the milk flavor less pure. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a sucrose-free low GI yogurt and a preparation method and application thereof, to solve the problems in the prior art.

[0006] To achieve the above-mentioned purposes and other related purposes, the present application is obtained by the following technical solutions.

[0007] The first aspect of the present application provides a sucrose-free low GI yogurt, which comprises the following raw material components: the content of D-allulose is 5-8 wt%, the content of white kidney bean extract is 1-3 wt%, the content of mulberry leaf extract is 0.5-2 wt%, the content of fermenting agent is 0.002-0.004 wt%, the content of stevioside is 0.006-0.014 wt%, and the balance is raw cow milk, based on the total mass of the yogurt raw materials.

[0008] The content of D-allulose can be 5 wt%, 6 wt%, 7 wt%, or 8 wt%; the content of white kidney bean extract can be 1 wt%, 2 wt%, or 3 wt%; the content of mulberry leaf extract can be 0.5 wt%, 1 wt%, 1.5 wt%, or 2 wt%; the content of fermenting agent can be 0.002 wt%, 0.003 wt%, or 0.004 wt%; and the content of stevioside can be 0.006 wt%, 0.008 wt%, 0.01 wt%, 0.012 wt%, or 0.014 wt%.

[0009] In this application, D-allulose, which has a zero glycemic index (GI) and does not participate in glucose metabolism, is used to replace commonly used filler sweeteners (such as sugar alcohols) in the prior art. This not only avoids the defects of filler sweeteners in terms of taste, such as a cooling sensation and bitter aftertaste, but also prevents poor flavor integration and incompatibility with dairy products. Furthermore, D-allulose has a sweetness of approximately 70% that of sucrose, with a pure taste and sweetness and no unpleasant aftertaste. As a raw material for dairy products, it will not introduce any unpleasant flavors, resulting in high product acceptability. In addition, D-allulose has zero effect on blood glucose after ingestion. As the C-3 diastereomer of D-fructose, it cannot be effectively metabolized by the human body and does not participate in glucose metabolism at all. Therefore, its glycemic index is 0, making it a zero-GI raw material, highly suitable for GI yogurt products.

[0010] Since D-allulose has a sweetness level of approximately 70% that of sucrose, in this application, only a trace amount of steviol glycosides is needed to compensate for the insufficient sweetness of D-allulose and optimize the sweetness profile. Furthermore, trace amounts of steviol glycosides provide excellent flavor and mouthfeel in dairy products. This combination of D-allulose and steviol glycosides not only precisely replicates the sweetness profile of sucrose but also retains as much of the sucrose's flavor as possible without using sucrose, while avoiding the high glycemic index of sucrose, making it highly beneficial for people controlling their blood sugar.

[0011] Preferably, the raw materials of the sugar-free, low-GI yogurt also include a stabilizer, and the amount of the stabilizer, based on the total mass of the yogurt raw materials, is no more than 0.2 wt%. For example, it can be 0.1 wt% or 0.2 wt%.

[0012] Preferably, the stabilizer is selected from one or more of pectin, agar, and gelatin.

[0013] Preferably, the fermenting agent is selected from one or more of *Lactobacillus delbrueckii* subsp. bulgaricus and *Streptococcus salivarius* subsp. thermophilus, respectively. The Latin names of *Lactobacillus delbrueckii* subsp. bulgaricus and *Streptococcus salivarius* subsp. thermophilus are respectively. More preferably, a combination of *Lactobacillus delbrueckii* subsp. bulgaricus and *Streptococcus salivarius* subsp. thermophilus is used, wherein the mass ratio of *Lactobacillus delbrueckii* subsp. bulgaricus to *Streptococcus salivarius* subsp. thermophilus is 1:1.

[0014] Preferably, the content of the α-amylase inhibitor in the white kidney bean extract is 500~5000 U / g. For example, it can be 500~700 U / g, 500~1000 U / g, 500~2000 U / g, or 500~3000 U / g.

[0015] White kidney bean extract is an active ingredient extracted from the endosperm of white kidney bean (Phaseolus vulgaris L.). Its core active ingredient is α-amylase inhibitor (α-AI), which is a glycoprotein that can inhibit the digestion and absorption of starch. It can block the breakdown of complex carbohydrates in food (such as starch) into absorbable monosaccharides in the intestine, thus it is widely used in the fields of weight management and blood sugar control.

[0016] Preferably, the content of 1-deoxynojirimycin (DNJ) in the mulberry leaf extract is ≥1 wt%.

[0017] Mulberry leaf extract is a functional ingredient extracted from the dried leaves of the mulberry tree (Morus alba L.), a plant in the Moraceae family. It is widely used in traditional Chinese medicine and modern functional foods. Its main active components are 1-deoxynojirimycin (DNJ), flavonoids (such as rutin and quercetin), phytosterols, and polysaccharides. Among these, the most crucial active ingredient in mulberry leaf extract is 1-deoxynojirimycin, an α-glucosidase inhibitor. DNJ effectively reduces postprandial blood glucose spikes by delaying sugar absorption, and has a clear auxiliary management effect on patients with prediabetes and type 2 diabetes.

[0018] In this application, the addition of white kidney bean extract and mulberry leaf extract effectively fills the solid content. Compared with existing technologies that use starch-based ingredients to fill the solid content, this not only avoids the thick, coarse texture and poor taste of yogurt products caused by excessive starch addition, but also avoids the intake of high-GI starch ingredients (such as corn starch with a GI value of 85), which can lead to drastic fluctuations in blood sugar. The addition of white kidney bean extract and mulberry leaf extract in this application ensures the yogurt's stable texture, moderate viscosity, and uniform consistency without compromising its taste. Furthermore, the active ingredients in white kidney bean extract and mulberry leaf extract can block the breakdown of complex carbohydrates (such as starch) in food into absorbable monosaccharides in the intestines, or slow down the absorption rate of glucose. This technical solution not only avoids the passive intake of sugar (including hidden sugars) at the source, but more importantly, it achieves active sugar control, perfectly meeting the requirements of low-GI products.

[0019] The second aspect of the present invention provides a method for preparing sugar-free, low-GI yogurt as described above, comprising the following steps: preheating raw milk, adding the D-allulose, white kidney bean extract, mulberry leaf extract and steviol glycosides to it, homogenizing and sterilizing, then inoculating with a starter culture for fermentation, and cooling and storing after fermentation is completed.

[0020] Preferably, the stabilizer is also added to the raw milk.

[0021] Preferably, the preheating temperature is 45~55℃. For example, it can be 45℃, 46℃, 47℃, 48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃, or 55℃.

[0022] Preferably, the homogenization temperature is 60~65℃. For example, it can be 60℃, 61℃, 62℃, 63℃, 64℃, or 65℃.

[0023] Preferably, the pressure during homogenization is 15~20MPa. For example, it can be 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, or 20MPa.

[0024] Preferably, the sterilization temperature is 90~95℃. For example, it can be 90℃, 91℃, 92℃, 93℃, 94℃, or 95℃.

[0025] Preferably, the sterilization time is 5 to 7 minutes. For example, it can be 5 minutes, 6 minutes, or 7 minutes.

[0026] Preferably, the fermentation temperature is 40~43℃. For example, it can be 40℃, 41℃, 42℃, or 43℃.

[0027] Preferably, fermentation is completed when the acidity reaches 70-75°T. For example, the acidity can be 70°T, 71°T, 72°T, 73°T, 74°T, or 75°T.

[0028] Preferably, the temperature for cooling and preservation is 0~10℃. For example, it can be 4~10℃, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃, or 10℃.

[0029] Beneficial effects:

[0030] The sugar-free, low-GI yogurt provided in this application not only achieves zero added sucrose but also avoids the use of starch-based ingredients commonly used as fillers in existing technologies, thereby further reducing the intake of glycemic carbohydrates and better meeting the characteristics of low-GI products. This application uses zero-GI D-allulose instead of filler sweeteners (such as sugar alcohols), resulting in a pure sweetness without unpleasant aftertaste, effectively avoiding the taste defects of filler sweeteners; and uses white kidney bean extract and mulberry leaf extract instead of commonly used starch-based ingredients to ensure stable yogurt texture, moderate viscosity, and uniform consistency.

[0031] Furthermore, the addition of D-allulose, white kidney bean extract, and mulberry leaf extract not only provides a pleasant sweetness and stabilizes the texture of yogurt by increasing its solid content, but also helps to stabilize blood sugar levels by inhibiting carbohydrate absorption, regulating sugar metabolism, and slowing down glucose absorption. This formula not only passively avoids carbohydrate intake at the source but also actively adjusts and stabilizes blood sugar levels, making it ideal for people who need to control their blood sugar. Detailed Implementation

[0032] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0033] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0034] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0035] In this application, GI is an indicator that measures how quickly carbohydrates in food raise blood sugar levels. Generally, foods are classified into three levels according to their GI value: low GI (GI value ≤ 55), medium GI (GI value 56 ~ 69), and high GI (GI value ≥ 70).

[0036] The starter culture in this application is a combination of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus; when used in combination, the mass ratio of the two is 1:1.

[0037] The white kidney bean extract used in this application contains 600 U / g of α-amylase inhibitor.

[0038] The mulberry leaf extract used in this application contains 1 wt% of 1-deoxynojirimycin (DNJ).

[0039] The D-allulose used in this application was purchased from Zhongda Hengyuan Biotechnology Co., Ltd., the white kidney bean extract was purchased from Shaanxi Haochen Biotechnology Co., Ltd., the mulberry leaf extract was purchased from Hunan Hill Natural Pharmaceutical Co., Ltd., the fermentation agent was purchased from Danisco (China) Co., Ltd., and the pectin and agar were purchased from Danisco (China) Co., Ltd.

[0040] Example 1

[0041] This embodiment provides a specific yogurt and its preparation method, the formula of which is: 5 wt% D-allulose, 3 wt% white kidney bean extract, 2 wt% mulberry leaf extract, 0.004 wt% starter culture, 0.014 wt% steviol glycosides, and 89.98 wt% raw milk.

[0042] Includes the following steps:

[0043] The raw milk is heated to 45°C, and the D-allulose, white kidney bean extract, mulberry leaf extract, and steviol glycosides are added. The mixture is homogenized (60°C, 20MPa) and pasteurized (95°C, 5 minutes). Then, it is cooled to 40°C, a starter culture is added, and fermentation is carried out at 40°C until the acidity reaches 70°T. The milk is then broken up, cooled to 4°C, and bottled to obtain the yogurt.

[0044] Example 2

[0045] This embodiment provides a specific yogurt and its preparation method, the formula of which is: 6 wt% D-allulose, 2 wt% white kidney bean extract, 1 wt% mulberry leaf extract, 0.002 wt% starter, 0.012 wt% steviol glycoside, 0.2 wt% compound stabilizer (pectin: agar mass ratio of 1:1) and 90.786 wt% raw milk.

[0046] Includes the following steps:

[0047] The raw milk is heated to 55°C, and the D-allulose, white kidney bean extract, mulberry leaf extract, steviol glycosides, and compound stabilizer are added. The mixture is homogenized (65°C, 15MPa) and pasteurized (90°C, 5 minutes). It is then cooled to 43°C, and a starter culture is added. Fermentation is carried out at 43°C until the acidity reaches 75°T. The milk is then broken down, cooled to 6°C, and bottled to obtain the yogurt.

[0048] Example 3

[0049] It is exactly the same as Example 2, except that no compound stabilizer is added.

[0050] Example 4

[0051] This embodiment provides a specific yogurt and its preparation method, the formula of which is: 8wt% D-allulose, 1wt% white kidney bean extract, 0.5wt% mulberry leaf extract, 0.004wt% starter culture, 0.006wt% steviol glycosides, and 90.49wt% raw milk.

[0052] Includes the following steps:

[0053] The raw milk is heated to 55°C, and the D-allulose, white kidney bean extract, mulberry leaf extract, and steviol glycosides are added. The mixture is homogenized (65°C, 15MPa) and pasteurized (95°C, 5 minutes). Then, it is cooled to 42°C, a starter culture is added, and fermentation is carried out at 42°C until the acidity reaches 70°T. The milk is then broken up, cooled to 10°C, and bottled to obtain the yogurt.

[0054] Comparative Example 1

[0055] This comparative example provides a conventional sucrose-containing yogurt in the prior art, with the following specific formula: 7 wt% white sugar, 0.004 wt% starter culture, and raw milk to make up to 100 wt%.

[0056] The process includes the following steps (process conditions are the same as in Example 1):

[0057] The raw milk is heated to 45°C, the white sugar is added, and the mixture is homogenized (60°C, 20MPa) and pasteurized (95°C, 5 minutes). Then it is cooled to 40°C, a starter culture is added, and fermentation is carried out at 40°C until the acidity reaches 70°T. The milk is then broken, cooled to 4°C, and bottled to obtain the final product.

[0058] Comparative Example 2

[0059] This comparative example provides a commonly used "high-intensity sweetener + filler sweetener" in the prior art to replace sucrose in a sugar-free yogurt. The specific formula is: erythritol 4 wt%, steviol glycoside 0.018 wt%, hydroxypropyl distarch phosphate 3 wt%, starter culture 0.004 wt%, and raw milk to make up to 100 wt%.

[0060] The process includes the following steps (process conditions are the same as in Example 1):

[0061] The raw milk is heated to 45°C, and erythritol, steviol glycosides, and hydroxypropyl distarch phosphate are added. The mixture is homogenized (60°C, 20MPa) and pasteurized (95°C, 5 minutes). Then, it is cooled to 40°C, and a starter culture is added. Fermentation is carried out at 40°C until the acidity reaches 70°T. The milk is then broken up, cooled to 4°C, and bottled to obtain the final product.

[0062] Comparative Example 3

[0063] This comparative example provides a yogurt that uses "high-intensity sweetener + filler sweetener" to replace sucrose, but does not add starchy ingredients. The specific formula is the same as that of comparative example 2, except that 3 wt% of hydroxypropyl distarch phosphate is not added.

[0064] The preparation method and conditions are the same as those for Comparative Example 2.

[0065] Comparative Example 4

[0066] Same as Example 1, but without the addition of white kidney bean extract and mulberry leaf extract; the rest of the formulation and preparation process are exactly the same as in Example 1.

[0067] Comparative Example 5

[0068] Same as Example 1, but without the addition of steviol glycosides; the rest of the formulation and preparation process are exactly the same as in Example 1.

[0069] The applicant investigated the shelf life (in days), protein, sugar (carbohydrate) content, and solid content of the yogurts obtained in Examples 1-3 and Comparative Examples 1-5 under refrigeration at 10 °C.

[0070] Shelf life under refrigeration: After the above yogurt samples were filled, they were placed in a constant temperature incubator at 10 ℃ to determine the shelf life. The shelf life was defined as when the total number of colonies in the sample exceeded 10,000 or the appearance was obviously deteriorated.

[0071] Protein content was determined according to the standard GB 5009.5 National Food Safety Standard - Determination of Protein in Food.

[0072] The sugar (carbohydrate) content was determined according to the standard GB 5009.8 National Food Safety Standard for the Determination of Fructose, Glucose, Sucrose, Maltose and Lactose in Food.

[0073] Solid content was determined according to the standard GB 5413.39-2010 National Food Safety Standard for Determination of Non-Fat Milk Solids in Milk and Dairy Products.

[0074] The specific results are shown in Table 1 below.

[0075] Table 1

[0076]

[0077] The sweetness calculation formula in this application is: Yogurt sweetness = amount of sweetener added × sweetness of sweetener, where the sweetness of granulated sugar (sucrose) is used as a reference, and 1 wt% of granulated sugar added is considered 1 level of sweetness. 1 wt% of D-allulose has a sweetness of 0.7, and 1 wt% of steviol glycosides has a sweetness of 250. Generally, regular yogurt has a sweetness level of 7-10, with 7 being the basic standard for meeting the sweet-sour ratio of yogurt products.

[0078] As shown in Table 1, the yogurt product provided by this application has a moderate sweetness, meeting the sweetness and acidity requirements of conventional yogurt products. Furthermore, compared to both Comparative Example 1 (conventional yogurt with added white sugar in the prior art) and Comparative Example 2 (0-sucrose yogurt using "high-intensity sweetener + filler sweetener" to replace sucrose in the prior art), the carbohydrate content of this product (Examples 1-3) is significantly lower. This indicates that the yogurt of this application has stricter control over carbohydrates at the source of intake, avoiding the intake of more carbohydrates. In addition, although the carbohydrate content of Example 4 is not significantly lower, its carbohydrates are not glycemic carbohydrates from white sugar or starch; rather, they are almost entirely derived from D-allulose. D-allulose has a GI value of 0 and does not cause a rise in blood sugar. Therefore, the technical solution of this application has stricter control over the content and type of carbohydrates at the source of intake, avoiding the intake of more glycemic carbohydrates.

[0079] Comparative Examples 2 and 3 show that in existing technologies using "high-intensity sweeteners + filler sweeteners" to replace sucrose, the addition of starch-derived stabilizers is essential. Without stabilizers such as hydroxypropyl distarch phosphate, the resulting yogurt product has excessively low solids content and unstable texture, leading to severe water separation during its shelf life. Therefore, sugar-free yogurt using "high-intensity sweeteners + filler sweeteners" to replace sucrose often only lacks added sucrose, but its carbohydrate content is not low. Compared to the technical solution of this application, it includes more glycemic-raising carbohydrates (such as starch-derived stabilizers), which is less conducive to blood sugar stability.

[0080] As can be seen from Comparative Example 4 and Example 1, when white kidney bean extract and mulberry leaf extract are not added, the solid content in yogurt is too low, which is not conducive to the stability of the yogurt's texture and will result in serious water separation problems during the shelf life.

[0081] As can be seen from Comparative Example 5 and Example 1, the combined use of D-allulose and steviol glycosides is an important technical approach. If only D-allulose is added without steviol glycosides, the sweetness and sourness of the final product will be affected, resulting in an overly sour taste that does not meet the typical sweetness and sourness ratio of yogurt.

[0082] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A sugar-free, low-GI yogurt, characterized in that, The yogurt contains the following raw material components: based on the total mass of the yogurt raw materials, the content of D-allulose is 5-8 wt%, the content of white kidney bean extract is 1-3 wt%, the content of mulberry leaf extract is 0.5-2 wt%, the content of starter culture is 0.002-0.004 wt%, the content of steviol glycosides is 0.006-0.014 wt%, and the balance is raw milk.

2. The yogurt according to claim 1, characterized in that, The raw materials of the sugar-free, low-GI yogurt also include a stabilizer, and the amount of the stabilizer is no more than 0.2 wt% based on the total mass of the yogurt raw materials.

3. The yogurt according to claim 2, characterized in that, The stabilizer is selected from one or more of pectin, agar, and gelatin.

4. The yogurt according to claim 1, characterized in that, The starter culture is selected from one or more of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus. And / or, in the white kidney bean extract, the content of the α-amylase inhibitor is 500~5000 U / g; And / or, in the mulberry leaf extract, the content of 1-deoxynojirimycin is ≥1 wt%.

5. A method for preparing sugar-free, low-GI yogurt as described in any one of claims 1 to 4, characterized in that, The process includes the following steps: preheating raw milk, adding the D-allulose, white kidney bean extract, mulberry leaf extract and steviol glycosides, homogenizing and sterilizing, then inoculating with a starter culture for fermentation, and cooling and storing after fermentation is complete.

6. The preparation method according to claim 5, characterized in that, The stabilizer is also added to the raw milk.

7. The preparation method according to claim 5, characterized in that, The preheating temperature is 45~55℃.

8. The preparation method according to claim 5, characterized in that, The temperature for homogenization is 60~65℃; And / or, the pressure during homogenization is 15~20MPa.

9. The preparation method according to claim 5, characterized in that, The sterilization temperature is 90~95℃; And / or, the fermentation temperature is 40~43℃; And / or, fermentation is complete when the acidity reaches 70~75°T.

10. The preparation method according to claim 5, characterized in that, The temperature for cooling and storage is 0~10℃.

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