Gas-containing fermented milk and preparation method thereof

Abstract

The invention provides gas-containing fermented milk and a preparation method thereof. The gas-containing fermented milk comprises the following components in parts by weight: 800-1000 parts of raw milk; 3 to 10 parts by weight of single cream; 3-8 parts by weight of casein powder; 5 to 15 parts by weight of an emulsifier; 1 to 3 parts by weight of sodium citrate; 2-5 parts by weight of egg yolk liquid; 0.1 part by weight to 0.5 part by weight of gellan gum; 0 to 100 parts by weight of a sweetening agent; and the strain: 50 U to 200 U. According to the gas-containing fermentation, the ratio of protein to fat in the gas-containing fermented milk is controlled, and the addition amount of other raw materials is optimized, so that the obtained gas-containing fermented braised milk is strong in taste, rich in flavor, good in taste and stable in texture.

Description

Technical Field

[0001] The invention relates to the technical field of carbonated fermented milk, and in particular to carbonated fermented milk and a preparation method thereof. Background Art

[0002] Yogurt is rich in nutrients and contains probiotics and special biological factors that help improve the gastrointestinal digestive function of the human body and enhance the body's immunity. It is a healthy drink that people choose in their daily life.

[0003] Currently, there are a small number of carbonated yogurt products on the market. As a new product form, carbonated yogurt is popular among consumers for its unique and refreshing taste. The gas in fermented milk can be filled externally, but the gas content is difficult to control. At the same time, the inflation process has a great impact on the stability of the product, leading to problems such as water precipitation. In addition to the external inflation method, the inflation method that uses bacterial metabolism to produce carbon dioxide during the fermentation process can also prepare carbonated yogurt with a distinct refreshing taste. However, carbonated fermented milk prepared by bacterial metabolism often has serious problems of water precipitation and post-acidification during the shelf life of the fermented milk due to the addition of sodium citrate, and the taste of carbonated fermented milk needs to be further improved. Summary of the invention

[0004] In view of this, the present invention provides a carbonated fermented milk and a preparation method thereof. The carbonated fermentation in the present invention is optimized by controlling the protein-to-fat ratio in the carbonated fermented milk and the addition amounts of other raw materials, so that the obtained carbonated fermented milk has a strong taste, rich flavor, good taste and stable texture.

[0005] In order to solve the technical problems raised in the background technology, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a carbonated fermented milk, wherein the carbonated fermented milk comprises:

[0007] Raw milk: 800 to 1000 parts by weight;

[0008] Cream: 3 to 10 parts by weight;

[0009] Casein powder: 3 to 8 parts by weight;

[0010] Emulsifier: 5 to 15 parts by weight;

[0011] Sodium citrate: 1 to 3 parts by weight;

[0012] Egg yolk liquid: 2 to 5 parts by weight;

[0013] Stabilizer: 0.1 to 0.5 parts by weight;

[0014] Sweetener: 0 to 100 parts by weight;

[0015] Bacteria strain: 50U~200U.

[0016] Furthermore, the stabilizer includes at least one of gellan gum, gelatin, pectin and agar.

[0017] Furthermore, the mass ratio of the added amount of the casein powder to the added amount of the cream is (3:8) to (2:1).

[0018] Furthermore, the mass ratio of the added amount of the egg yolk liquid to the added amount of the stabilizer is (3-4):0.2.

[0019] Furthermore, the mass ratio of the added amount of the casein powder to the added amount of the sodium citrate is (3-8):(2-3).

[0020] Furthermore, the emulsifier includes at least one of diacetyl tartaric acid mono- and diglycerides and mono- and diglycerol fatty acid esters.

[0021] Furthermore, the bacterial species includes at least one of Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris.

[0022] In a second aspect, the present invention provides a method for preparing the carbonated fermented milk as described above, the preparation method comprising: adding 3 to 8 parts by weight of casein powder, 3 to 10 parts by weight of cream, 0 to 100 parts by weight of sweetener, 5 to 15 parts by weight of emulsifier, 2 to 5 parts by weight of egg yolk liquid, 0.1 to 0.5 parts by weight of gellan gum and 1 to 3 parts by weight of sodium citrate to 800 to 1000 parts by weight of raw cow's milk, stirring and then degassing, homogenizing and sterilizing in sequence to obtain a fermented milk base; adding 50U to 200U of bacterial strains to the fermented milk base, stirring and then filling and fermenting, and refrigerating and ripening after fermentation to obtain the carbonated fermented milk.

[0023] Furthermore, the method for preparing the carbonated fermented milk comprises the following steps:

[0024] (1) Milk pretreatment: add 3 to 8 parts by weight of casein powder and 3 to 10 parts by weight of cream to 800 to 1000 parts by weight of raw milk, and stir evenly;

[0025] (2) Ingredients: adding 0 to 100 parts by weight of a sweetener, 5 to 15 parts by weight of an emulsifier, 2 to 5 parts by weight of egg yolk liquid, 0.1 to 0.5 parts by weight of gellan gum, and 1 to 3 parts by weight of sodium citrate to the milk pretreated in step (1);

[0026] (3) degassing, homogenizing and sterilizing the pre-emulsified milk in step (2) to obtain a fermented milk base;

[0027] (4) Cooling the fermented milk base in step (3) to 30-35° C., adding 50U to 200U of the bacterial strain, and stirring evenly; then filling and fermenting, and refrigerating and ripening after fermentation to obtain the carbonated fermented milk.

[0028] Furthermore, in the step (3), degassing is performed at 60-70°C and 18-20MPa; homogenization is performed at a pressure of 200-220bar; and sterilization is performed at 93-95°C for 280-300s; in the step (4), the fermentation temperature is 28-32°C, and the fermentation is terminated when the acidity reaches 70-80°T, and the temperature of refrigerated post-ripening is 4-6°C.

[0029] The beneficial effects of the above technical solution of the present invention are as follows:

[0030] The present invention provides a carbonated fermented milk, which comprises: raw cow's milk: 800 to 1000 parts by weight; cream: 3 to 10 parts by weight; casein powder: 3 to 8 parts by weight; emulsifier: 5 to 15 parts by weight; sodium citrate: 1 to 3 parts by weight; egg yolk liquid: 2 to 5 parts by weight; stabilizer: 0.1 to 0.5 parts by weight; sweetener: 0 to 100 parts by weight; and bacterial strain: 50U to 200U.

[0031] In the present invention, the fat and total protein content is controlled to enhance the product's mouthfeel and eliminate the product's granular mouthfeel; the ratio of the added amount of egg yolk liquid and gellan gum is controlled to enhance the stability of the product's texture, making it easy to suck with a straw; by controlling the ratio of the added amount of sodium citrate and casein, on the one hand, the fermentation gas production of the bacteria is increased, and on the other hand, the quality of the fermented milk is improved, the problem of post-fermentation acidity of the fermented milk is improved, and water precipitation is prevented. In summary, the gas-containing fermentation in the present invention controls the protein-fat ratio in the gas-containing fermented milk and optimizes the addition amount of other raw materials, so that the obtained gas-containing fermented milk has a strong mouthfeel, rich flavor, good taste and stable texture. DETAILED DESCRIPTION

[0032] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the present invention.

[0033] In a first aspect, the present invention provides a carbonated fermented milk, wherein the carbonated fermented milk comprises:

[0034] Raw milk: 800 to 1000 parts by weight;

[0035] Cream: 3 to 10 parts by weight;

[0036] Casein powder: 3 to 8 parts by weight;

[0037] Emulsifier: 5 to 15 parts by weight;

[0038] Sodium citrate: 1 to 3 parts by weight;

[0039] Egg yolk liquid: 2 to 5 parts by weight;

[0040] Stabilizer: 0.1 to 0.5 parts by weight;

[0041] Sweetener: 0 to 100 parts by weight;

[0042] Bacteria strain: 50U~200U.

[0043] The raw cow's milk of the present invention has the following indexes: 100g of raw cow's milk contains 3.0g of protein and 3.2g of fat.

[0044] According to some embodiments of the present invention, the stabilizer includes at least one of gellan gum, gelatin, pectin and agar.

[0045] According to some embodiments of the present invention, the mass ratio of the added amount of the casein powder to the added amount of the cream is (3:8) to (2:1).

[0046] According to some embodiments of the present invention, the mass ratio of the added amount of the egg yolk liquid to the added amount of the stabilizer is (3-4):0.2.

[0047] According to some embodiments of the present invention, the mass ratio of the added amount of the casein powder to the added amount of the sodium citrate is (3-8): (2-3).

[0048] According to some embodiments of the present invention, the bacterial species include at least one of Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris and Leuconostoc mesenteroides. Preferably, the bacterial species are Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris.

[0049] According to some embodiments of the present invention, the emulsifier includes at least one of diacetyl tartaric acid mono- and diglycerides and mono- and diglycerol fatty acid esters.

[0050] The present invention provides a carbonated fermented milk, wherein the carbonated fermented milk generates gas (CO) during the fermentation process by utilizing bacterial metabolism. 2) to achieve the inflation effect. Furthermore, the inventors found that when using strain fermentation to prepare carbonated fermented milk, the total protein content in cow's milk and the ratio of fat content to total protein content in cow's milk will affect the strength of the flavor of the carbonated fermented milk and the taste of the product. Specifically, the mass ratio of the amount of casein powder added to the amount of cream added is (3:8) to (2:1) to enhance the strength of the flavor of the product and eliminate the granular taste of the product. At the same time, carbonated fermented milk is prone to problems such as difficulty in sucking and emptying when sucked with a straw due to internal inflation. The present invention finds that adding egg yolk liquid and gellan gum, and controlling the ratio of the amount of egg yolk liquid to gellan gum added within a reasonable range, can enhance the stability of the product texture and make it easy to suck with a straw. Specifically, the mass ratio of the amount of egg yolk liquid added to the amount of gellan gum added in the present invention is controlled to be (3-4):0.2. Finally, the present invention also found that the amount of sodium citrate and casein added and the ratio of the added amounts will affect the gas content of the carbonated fermented milk and the texture stability of the product. Specifically, the mass ratio of the amount of casein powder added and the amount of sodium citrate added in the present invention is controlled to be (3-8): (2-3). Within this range, on the one hand, the fermentation gas production of the strain can be increased, and on the other hand, the quality of carbonated fermented milk can be improved, the problem of post-fermentation acidity of the fermented milk can be improved, and water precipitation can be prevented. In summary, the carbonated fermentation in the present invention controls the protein-fat ratio in the carbonated fermented milk and optimizes the amount of other raw materials added, so that the carbonated fermented milk has a strong taste, rich flavor, good taste and stable texture.

[0051] In a second aspect, the present invention provides a method for preparing the carbonated fermented milk as described above, the preparation method comprising: adding 3 to 8 parts by weight of casein powder, 3 to 10 parts by weight of cream, 0 to 100 parts by weight of sweetener, 5 to 15 parts by weight of emulsifier, 2 to 5 parts by weight of egg yolk liquid, 0.1 to 0.5 parts by weight of gellan gum and 1 to 3 parts by weight of sodium citrate to 800 to 1000 parts by weight of raw cow's milk, stirring and then degassing, homogenizing and sterilizing in sequence to obtain a fermented milk base; adding 50U to 200U of bacterial strains to the fermented milk base, stirring and then filling and fermenting, and refrigerating and ripening after fermentation to obtain the carbonated fermented milk.

[0052] According to some embodiments of the present invention, the method for preparing carbonated fermented milk comprises the following steps:

[0053] (1) Milk pretreatment: add 3 to 8 parts by weight of casein powder and 3 to 10 parts by weight of cream to 800 to 1000 parts by weight of raw milk, and stir evenly;

[0054] (2) Ingredients: adding 0 to 100 parts by weight of a sweetener, 5 to 15 parts by weight of an emulsifier, 2 to 5 parts by weight of egg yolk liquid, 0.1 to 0.5 parts by weight of gellan gum, and 1 to 3 parts by weight of sodium citrate to the milk pretreated in step (1);

[0055] (3) Degassing, homogenizing and sterilizing the pre-emulsified milk in step (2) to obtain a fermented milk base.

[0056] (4) Cooling the fermented milk base in step (3) to 30-35° C., adding 50U to 200U of the bacterial strain, and stirring evenly; then filling and fermenting, and refrigerating and ripening after fermentation to obtain the carbonated fermented milk.

[0057] According to some embodiments of the present invention, in step (3), degassing is performed at 60-70° C. and 18-20 MPa; homogenization is performed at a pressure of 200-220 bar; and sterilization is performed at 93-95° C. for 280-300 s.

[0058] According to some embodiments of the present invention, in step (4), the fermented milk base after filling is left to ferment at 28-32°C until the acidity reaches 70-80°T. After the fermentation is completed, the fermented milk is cooled to 10°C within 15 minutes and refrigerated for ripening to obtain carbonated fermented milk.

[0059] The present invention will be further described below through some specific embodiments.

[0060] Example 1

[0061] This embodiment provides a method for preparing carbonated fermented milk, which includes two processes of preparing a fermented milk base and preparing fermented milk, and specifically includes the following steps:

[0062] 1. Prepare fermented milk base:

[0063] (1) Milk pretreatment: Add 3 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0064] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0065] (3) Degas the pre-emulsified milk in step (2) at 65° C. and 18 MPa; homogenize at a pressure of 220 bar; and finally sterilize at 95° C. for 300 s to obtain a fermented milk base.

[0066] 2. Preparation of carbonated fermented milk:

[0067] (1) Cool the fermented milk base to 30-35° C., add 0.02 g of starter culture (75 U each of Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris), and stir evenly;

[0068] (2) Filling and fermentation: The filling and sealing processes are carried out in a closed aseptic filling device. The fermented milk base after filling is left to ferment at 30°C. After fermentation to an acidity of 70°, the fermented milk is cooled to 10°C within 15 minutes and refrigerated for ripening to obtain carbonated fermented milk.

[0069] Example 2

[0070] 1. Prepare fermented milk base:

[0071] (1) Milk pretreatment: add 8 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0072] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0073] (3) Degas the pre-emulsified milk in step (2) at 65° C. and 18 MPa; homogenize at a pressure of 220 bar; and finally sterilize at 95° C. for 300 s to obtain a fermented milk base.

[0074] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0075] Example 3

[0076] 1. Prepare fermented milk base:

[0077] (1) Milk pretreatment: add 3 g of casein powder and 8 g of cream to 900 g of milk and stir for 10 min until uniform;

[0078] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0079] (3) Degas the pre-emulsified milk in step (2) at 65° C. and 18 MPa; homogenize at a pressure of 220 bar; and finally sterilize at 95° C. for 300 s to obtain a fermented milk base.

[0080] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0081] Example 4

[0082] 1. Prepare fermented milk base:

[0083] (1) Milk pretreatment: Add 3 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0084] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides, 4 g of egg yolk liquid, 0.2 g of gellan gum, and 1 g of sodium citrate to the milk pretreated in step (1);

[0085] (3) Degas the pre-emulsified milk in step (2) at 65° C. and 18 MPa; homogenize at a pressure of 220 bar; and finally sterilize at 95° C. for 300 s to obtain a fermented milk base.

[0086] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0087] Example 5

[0088] 1. Prepare fermented milk base:

[0089] (1) Milk pretreatment: Add 3 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0090] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides, 3 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0091] (3) Degas the pre-emulsified milk in step (2) at 65° C. and 18 MPa; homogenize at a pressure of 220 bar; and finally sterilize at 95° C. for 300 s to obtain a fermented milk base.

[0092] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0093] Comparative Example 1

[0094] 1. Prepare fermented milk base:

[0095] (1) Milk pretreatment: add 3 g of casein powder to 900 g of milk without adding cream and stir for 10 min until uniform;

[0096] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0097] (3) Degassing the pre-emulsified liquid in step (2) at 65° C. and 18 MPa; homogenizing at a pressure of 220 bar; and finally sterilizing at 95° C. for 300 s to obtain a fermented milk base.

[0098] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0099] Comparative Example 2

[0100] 1. Prepare fermented milk base:

[0101] (1) Milk pretreatment: add 1 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0102] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0103] (3) Degassing the pre-emulsified liquid in step (2) at 65° C. and 18 MPa; homogenizing at a pressure of 220 bar; and finally sterilizing at 95° C. for 300 s to obtain a fermented milk base.

[0104] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0105] Comparative Example 3

[0106] 1. Prepare fermented milk base:

[0107] (1) Milk pretreatment: add 10 g casein powder and 4 g cream to 900 g milk and stir for 10 min until uniform;

[0108] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0109] (3) Degassing the pre-emulsified liquid in step (2) at 65° C. and 18 MPa; homogenizing at a pressure of 220 bar; and finally sterilizing at 95° C. for 300 s to obtain a fermented milk base.

[0110] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0111] Comparative Example 4

[0112] 1. Prepare fermented milk base:

[0113] (1) Milk pretreatment: Add 3 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0114] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 1 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0115] (3) Degassing the pre-emulsified liquid in step (2) at 65° C. and 18 MPa; homogenizing at a pressure of 220 bar; and finally sterilizing at 95° C. for 300 s to obtain a fermented milk base.

[0116] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0117] Comparative Example 5

[0118] 1. Prepare fermented milk base:

[0119] (1) Milk pretreatment: Add 3 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0120] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides, 6 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0121] (3) Degassing the pre-emulsified liquid in step (2) at 65° C. and 18 MPa; homogenizing at a pressure of 220 bar; and finally sterilizing at 95° C. for 300 s to obtain a fermented milk base.

[0122] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0123] Comparative Example 6

[0124] 1. Prepare fermented milk base:

[0125] (1) Milk pretreatment: Add 3 g of casein powder and 4 g of cream to 900 g of milk and stir for 10 min until uniform;

[0126] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides, 1 g of egg yolk liquid, 0.2 g of gellan gum, and 3.5 g of sodium citrate to the milk pretreated in step (1);

[0127] (3) Degassing the pre-emulsified liquid in step (2) at 65° C. and 18 MPa; homogenizing at a pressure of 220 bar; and finally sterilizing at 95° C. for 300 s to obtain a fermented milk base.

[0128] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0129] Comparative Example 7

[0130] 1. Prepare fermented milk base:

[0131] (1) Milk pretreatment: add 3 g whey protein powder and 4 g cream to 900 g milk and stir for 10 min until uniform;

[0132] (2) Ingredients: Add 70 g of white sugar, 10 g of diacetyl tartaric acid mono- and diglycerides (emulsifier), 4 g of egg yolk liquid, 0.2 g of gellan gum, and 2.5 g of sodium citrate to the milk pretreated in step (1);

[0133] (3) Degas the pre-emulsified milk in step (2) at 65° C. and 18 MPa; homogenize at a pressure of 220 bar; and finally sterilize at 95° C. for 300 s to obtain a fermented milk base.

[0134] 2. Preparation of carbonated fermented milk: The preparation method is the same as that in Example 1.

[0135] Test Example 1

[0136] The gas-containing fermented milk prepared in Examples 1-5 and Comparative Examples 1-7 was subjected to sensory evaluation in terms of taste and flavor. The main evaluation items included: tissue state (whey separation, fat floating, viscosity, fineness, texture, etc.), color, flavor (including fat taste), mouthfeel, etc. A total of 30 people participated in the experiment, and the fermented milk products of Examples 1-5 and Comparative Examples 1-7 were subjected to sensory evaluation. The sensory scoring standard is shown in Table 1, and the experimental record results are summarized in Table 2.

[0137] Table 1

[0138]

[0139]

[0140] Table 2

[0141]

[0142] Table 2

[0143]

[0144]

[0145] Table 2

[0146]

[0147] From the results in Table 2, it can be seen that the flavored fermented milks of Examples 1 to 5 all have good tissue state, taste and flavor, the products have no whey precipitation, no fat floating, rich characteristic flavor, harmonious aroma, strong taste, delicate taste, moderate sourness and sweetness, and uniform taste.

[0148] Comparing Examples 1 to 5 with Comparative Examples 1 to 7, it can be seen that the following factors may affect the sensory evaluation of the product:

[0149] 1. Total protein content: Through the analysis of Examples 1 to 3 and Comparative Examples 2 and 3, it was found that the texture of carbonated fermented milk can be controlled by adding casein to achieve a suitable protein ratio in the milk base, which will increase the taste and stability of the product and make the fermented milk taste richer.

[0150] 2. The ratio of protein to fat: Through the analysis of Examples 1 to 3 and Comparative Examples 1 and 2, controlling the ratio of protein to fat in the fermented milk is beneficial to the establishment of the texture of the fermented milk under gas-containing conditions.

[0151] 3. The addition ratio of egg yolk liquid and gellan gum: Through the analysis of Example 1 and Comparative Examples 5 and 6, the appropriate addition ratio of egg yolk liquid and gellan gum is beneficial to enriching the taste and establishing a stable organizational structure of fermented milk. When too much egg yolk liquid is added, the texture of the fermented milk will be destroyed.

[0152] 4. Type of protein added: Through the analysis of Example 1 and Comparative Example 7, the addition of casein helps to establish a product stabilization system and control whey precipitation.

[0153] Test Example 2

[0154] For the carbonated fermented milk prepared in Examples 1 to 4 and Comparative Examples 2, 3, 6 and 7, the water holding capacity was determined by centrifugation, and the hardness, consistency and cohesiveness were determined. Specific test results are shown in Table 3.

[0155] Table 3

[0156] Sample code Water holding capacity / % Hardness / g Consistency / g·s Cohesiveness / g Example 1 75.16 229.86 5122.46 -71.77 Example 2 77.45 211.43 5043.32 -78.33 Example 3 75.26 236.87 5003.95 -75.21 Example 4 78.56 216.24 5423.07 -74.23 Comparative Example 2 66.88 183.55 4301.52 -86.54 Comparative Example 3 64.56 196.93 4637.85 -89.49 Comparative Example 6 68.45 196.23 4520.02 -90.56 Comparative Example 7 65.28 194.39 4409.75 -80.75

[0157] From the results in Table 3, it can be seen that compared with Comparative Examples 2 and 3, Examples 1 and 2 are significantly higher in water holding capacity, consistency, and cohesiveness than Comparative Examples 2 and 3. The reason is that when the protein content in cow's milk is 3.5-4.0, the milk base can still maintain a good texture and good water holding capacity under the condition of being filled with gas. In addition to the protein content in fermented milk, the content ratio of sodium citrate to casein is also directly related to the stability of fermented milk products. By comparing Examples 1 and 4 with Comparative Examples 2, 3, and 6, too high or too low a ratio of sodium citrate to casein will have a negative impact on the texture of gas-containing fermented milk, increase water separation, and reduce the hardness and viscosity of the product. By comparing Example 1 and Comparative Example 7, the total protein index is regulated by casein, which has a better effect than using whey protein powder, which is mainly reflected in the water holding capacity and hardness indexes.

[0158] Test Example 3

[0159] The samples of carbonated fermented milk prepared in Examples 1, 2, 4 and Comparative Examples 2 and 6 were placed at 25° C. for 28 days, and the acidity was measured every 7 days. The specific test results are shown in Table 4.

[0160] Table 4

[0161]

[0162]

[0163] From the results in Table 4, it can be seen that the after-acid problem of fermented milk can be improved by adjusting the addition ratio of sodium citrate to casein, and the taste of the product can be effectively guaranteed.

[0164] Test Example 4

[0165] The carbon dioxide production of the carbonated fermented milk prepared in Examples 1, 2, 4 and Comparative Examples 5, 6, and 7 was measured by a pressure reducer method at 20°C and the fermentation rate was measured with an acidity of 70°T as the fermentation end point. The specific test results are shown in Table 5.

[0166] Table 5

[0167]

[0168] It can be seen from the results in Table 5 that the amount of sodium citrate added is directly related to the gas production. By comparing Examples 1, 2, and 4 with Comparative Example 6, it can be seen that as the amount of sodium citrate added increases, the gas production value increases. By comparing Examples 1 and 2 with Comparative Example 6, it can be seen that when the amount of sodium citrate added exceeds 3.5 thousandths, there is no obvious difference in the gas production value, but the fermentation time will be seriously prolonged. By analyzing Example 1 and Comparative Example 7, the gas production is slightly less when whey protein is added than when casein is added, and the difference is not obvious. Combined with Test Examples 1 and 2, it can be seen that different types of added protein mainly affect the sensory experience of the taste and product texture, and have little effect on the gas production.

[0169] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A carbonated fermented milk, characterized in that: The gas-containing fermented milk comprises: Raw milk: 800 to 1000 parts by weight; Cream: 3 to 10 parts by weight; Casein powder: 3 to 8 parts by weight; Emulsifier: 5 to 15 parts by weight; Sodium citrate: 1 to 3 parts by weight; Egg yolk liquid: 2 to 5 parts by weight; Stabilizer: 0.1 to 0.5 parts by weight; Sweetener: 0 to 100 parts by weight; Bacteria strain: 50U~200U.

2. The carbonated fermented milk according to claim 1, characterized in that The stabilizer includes at least one of gellan gum, gelatin, pectin and agar.

3. The carbonated fermented milk according to claim 1, characterized in that: The mass ratio of the added amount of the casein powder to the added amount of the light cream is (3:8) to (2:1).

4. The carbonated fermented milk according to claim 1, characterized in that: The mass ratio of the added amount of the egg yolk liquid to the added amount of the stabilizer is (3-4):0.

2.

5. The carbonated fermented milk according to claim 1, characterized in that: The mass ratio of the added amount of the casein powder to the added amount of the sodium citrate is (3-8):(2-3).

6. The carbonated fermented milk according to claim 1, characterized in that: The emulsifier includes at least one of diacetyl tartaric acid mono- and diglycerol and mono- and diglycerol fatty acid esters.

7. The carbonated fermented milk according to claim 1, characterized in that: The bacterial species include at least one of Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris and Leuconostoc mesenteroides.

8. The method for producing carbonated fermented milk according to any one of claims 1 to 7, characterized in that: The preparation method comprises: In 800 to 1000 parts by weight of raw cow milk, 3 to 8 parts by weight of casein powder, 3 to 10 parts by weight of cream, 0 to 100 parts by weight of sweetener, 5 to 15 parts by weight of emulsifier, 2 to 5 parts by weight of egg yolk liquid, 0.1 to 0.5 parts by weight of gellan gum and 1 to 3 parts by weight of sodium citrate are added, and after stirring, degassing, homogenizing and sterilizing are performed in sequence to obtain a fermented milk base; 50U to 200U of bacterial strains are added to the fermented milk base, and after stirring, filling and fermentation are performed, and after fermentation, refrigeration and post-ripening are performed to obtain the carbonated fermented milk.

9. The preparation method according to claim 8, characterized in that: The preparation method comprises the following steps: (1) Milk pretreatment: add 3 to 8 parts by weight of casein powder and 3 to 10 parts by weight of cream to 800 to 1000 parts by weight of raw milk, and stir evenly; (2) Ingredients: adding 0 to 100 parts by weight of a sweetener, 5 to 15 parts by weight of an emulsifier, 2 to 5 parts by weight of egg yolk liquid, 0.1 to 0.5 parts by weight of gellan gum, and 1 to 3 parts by weight of sodium citrate to the milk pretreated in step (1); (3) degassing, homogenizing and sterilizing the pre-emulsified milk in step (2) to obtain a fermented milk base; (4) Cooling the fermented milk base in step (3) to 30-35° C., adding 50U to 200U of the bacterial strain, and stirring evenly; then filling and fermenting, and refrigerating and ripening after fermentation to obtain the carbonated fermented milk.

10. The preparation method according to claim 9, characterized in that: In the step (3), degassing is carried out at 60-70° C. and 18-20 MPa; Homogenize at 200-220 bar pressure; Sterilize at 93-95℃ for 280-300s; In the step (4), the fermentation temperature is 28-32°C, and the fermentation is terminated when the acidity reaches 70-80°T. The temperature of the refrigerated ripening is 4-6°C.

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