CN117814313A

CN117814313A - Flavored milk and preparation method thereof

Info

Publication number: CN117814313A
Application number: CN202311811215.7A
Authority: CN
Inventors: 姜雪; 徐致远; 刘振民; 王辉; 艾正文; 徐杭蓉; 赵艳荷; 叶景锦
Original assignee: Bright Dairy and Food Co Ltd
Current assignee: Bright Dairy and Food Co Ltd
Priority date: 2023-12-26
Filing date: 2023-12-26
Publication date: 2024-04-05

Abstract

The invention belongs to the technical field of flavored milk preparation, and particularly relates to flavored milk and a preparation method thereof. The invention provides flavored milk, which comprises the following raw materials in percentage by mass: 50 to 85 percent of raw milk, 0.5 to 5 percent of fruit concentrated juice, 0.01 to 4 percent of sweetener, 0.17 to 0.65 percent of stabilizer, 0.01 to 0.06 percent of buffer salt and the balance of water. The flavored milk disclosed by the invention contains higher protein content, is rich in active substances such as immunoglobulin, lactoferrin and the like, and has a longer shelf life.

Description

Flavored milk and preparation method thereof

Technical Field

The invention belongs to the technical field of flavored milk preparation, and particularly relates to flavored milk and a preparation method thereof.

Background

In the report of inflight, the flavor milk market has a higher growth rate in the next five years due to the increasing awareness of consumers for flavor milk and the endlessly layered cross-border products in recent years, so that the flavor milk is still an important product matrix in dairy products.

As a major class in the beverage industry, innovation of flavored milk focuses on flavor, and is biased to the current beverage products such as tea shops and coffee shops. With consumer nutritional awareness improvement, in addition to flavor innovations, the nutritional content or ingredient remains the direction in which flavored milk needs to be concentrated or improved. From the aspect of nutrition of milk, the milk is rich in protein, fat, lactose and multiple vitamins, and the milk protein also contains amino acids required by human bodies. The milk fat contains fatty acid and phospholipid which are necessary for human beings, and is one of the most ideal natural health-care food. The precious natural substances such as immunoglobulin, lactoferrin and the like are more important as the core value of milk, and have the effects of resisting pathogens such as bacteria, viruses and the like, enhancing the immunity of organisms and the like. By digging the nutritional value of the milk beverage, more active nutrition is reserved, the added value of the milk beverage is increased, the current blank is filled for the milk beverage market, and the milk beverage is matched with the concept and the consumption requirement of consumers.

However, the characteristics of the dairy products are limited, and in order to prolong the shelf life of the flavored milk, sterilization treatment is needed in the preparation process, but improper sterilization treatment ensures the shelf life of the flavored milk and simultaneously causes great loss of protein active substances in the flavored milk, so that the problem that the shelf life and the active substances cannot be both guaranteed in the existing commercial flavored milk is generally solved.

Disclosure of Invention

The invention aims to provide flavored milk which is rich in active substances and has a long shelf life, and a preparation method thereof.

The invention provides flavored milk, which comprises the following raw materials in percentage by mass:

50 to 85 percent of raw milk, 0.5 to 5 percent of fruit concentrated juice, 0.01 to 4 percent of sweetener, 0.17 to 0.65 percent of stabilizer, 0.01 to 0.06 percent of buffer salt and the balance of water.

Preferably, the content of soluble solids in the fruit concentrated juice is 40% -60%, and the pH value is 3.5-6.2.

Preferably, the sweetener comprises one or more of white granulated sugar, fructose, erythritol, fructose-glucose syrup, sucralose and steviol glycoside.

Preferably, the stabilizer comprises an emulsifier and a thickener; the content of the emulsifying agent is 0.16-0.3% of the mass of the preparation raw material; the content of the thickener is 0.01-0.35% of the mass of the preparation raw material; the emulsifier comprises one or more of glycerin monostearate, sucrose fatty acid ester, molecular distillation monoglyceride, modified soybean phosphate and citric acid fatty acid ester; the thickener comprises one or more of microcrystalline cellulose, sodium carboxymethyl cellulose, carrageenan, acacia and guar gum.

Preferably, the buffer salt comprises one or more of sodium hexametaphosphate, sodium tripolyphosphate, dipotassium hydrogen phosphate, and sodium bicarbonate.

The invention also provides a preparation method of the flavored milk, which comprises the following steps:

degreasing raw milk to obtain skimmed milk and cream;

performing membrane filtration treatment on the skim milk to obtain filtrate;

mixing the filtrate with fruit concentrated juice, sweetener, stabilizer, buffer salt and water at 40-50 ℃ for the first time to obtain a mixed material;

performing first sterilization treatment on the cream to obtain sterilized cream, wherein the temperature of the first sterilization treatment is 120-157 ℃;

and (3) carrying out second mixing on the mixed material and sterilized cream, and carrying out homogenization treatment and second sterilization treatment to obtain the flavored milk.

Preferably, the membrane pore diameter of the membrane filtration treatment is 0.8-1.4 μm, and the temperature is 45-55 ℃.

Preferably, the time of the first sterilization treatment is 0.09-15 s; the first mixing time is 10-20 min.

Preferably, the temperature of the homogenizing treatment is 55-65 ℃ and the pressure is 18-30 MPa; the temperature of the second sterilization treatment is 72-75 ℃ and the time is 15-20 s.

Preferably, the degreasing treatment is preceded by concentration treatment of raw milk, wherein the multiple of the concentration treatment is 1.3-2.0 times, and the temperature is 4-55 ℃; the degreasing treatment comprises centrifugal degreasing treatment, wherein the temperature of the centrifugal degreasing treatment is 40-55 ℃.

The beneficial effects are that:

the invention also provides a preparation method of the flavored milk, which comprises the following steps: degreasing raw milk to obtain skimmed milk and cream; performing membrane filtration treatment on the skim milk to obtain filtrate; mixing the filtrate with fruit concentrated juice, sweetener, stabilizer, buffer salt and water at 40-50 ℃ for the first time to obtain a mixed material; performing first sterilization treatment on the cream to obtain sterilized cream, wherein the temperature of the first sterilization treatment is 120-157 ℃; and (3) carrying out second mixing on the mixed material and sterilized cream, and carrying out homogenization treatment and second sterilization treatment to obtain the flavored milk. The invention effectively removes microorganisms in raw milk and cream by respectively carrying out membrane filtration treatment sterilization and high-temperature sterilization on the skim milk and the cream, thereby achieving the aim of sterilization from the preparation raw material; meanwhile, by setting the proper heat preservation temperature in the first mixing and sterilizing the obtained flavored milk, the reasonable sterilization time, sterilization temperature and sterilization time can ensure the quality guarantee period of the flavored milk while improving the activity and content of active substances in the flavored milk, and the flavored milk has higher industrial utilization value.

Meanwhile, the invention also provides flavored milk, which comprises the following raw materials in percentage by mass: 50 to 85 percent of raw milk, 0.5 to 5 percent of fruit concentrated juice, 0.01 to 4 percent of sweetener, 0.17 to 0.65 percent of stabilizer, 0.01 to 0.06 percent of buffer salt and the balance of water. The flavored milk disclosed by the invention has higher protein content, and the contents of active substances such as immunoglobulin, lactoferrin and the like are also higher, and meanwhile, a longer shelf life can be ensured.

Detailed Description

The preparation raw materials of the flavored milk comprise 50-85% of raw milk, preferably 55-80%, and more preferably 60-75% of raw milk by mass percent. The raw milk preferably meets the standard of 'national Standard raw milk for food safety'. The raw milk of the invention preferably comprises raw milk obtained by degerming or concentrating raw milk; the sterilization treatment preferably includes a centrifugal sterilization treatment, the process of which is not particularly limited, and may be performed according to the operation of conventional centrifugal treatment in the art; the total bacterial count in the raw milk after the sterilization treatment is preferably less than or equal to 50000CFU/mL; the concentration treatment preferably comprises reverse osmosis membrane concentration, falling film concentration or flash evaporation; specific operation steps of reverse osmosis membrane concentration, falling film concentration or flash evaporation are not particularly limited, and conventional operation steps in the field can be adopted. The protein content in the raw milk is preferably 2.9-6.2%, and the fat content is preferably 3.1-7.0%.

The raw materials for preparing the flavored milk comprise 0.5 to 5 percent of fruit concentrated juice, preferably 1.5 to 3.5 percent, based on the content of the raw material milk. The content of soluble solids in the fruit concentrated juice is preferably 40% -60%; the fruit juice concentrate preferably includes, but is not limited to, one or more of pear juice concentrate, watermelon juice concentrate, strawberry juice concentrate, peach juice concentrate, and apple juice concentrate; when the fruit juice concentrate comprises various fruit juice concentrates, the mass ratio among the various fruit juice concentrates is not particularly limited, and the fruit juice concentrates can be adjusted conventionally according to production or taste requirements. The pH value of the fruit concentrated juice is preferably 3.5-6.2.

The raw materials for preparing the flavored milk comprise 0.01 to 4 percent of sweetener, preferably 0.5 to 3.5 percent, and more preferably 2 to 3.01 percent by taking the content of the raw material milk as a reference; the sweetener preferably comprises one or more of white granulated sugar, fructose, erythritol, fructose-glucose syrup, sucralose and stevioside, more preferably one or more of white granulated sugar, fructose, erythritol and stevioside, and even more preferably white granulated sugar; when a plurality of sweeteners are included, the mass ratio between the plurality of sweeteners is not particularly limited, and may be adjusted conventionally according to production requirements and tastes. The sweetener added in the amount of the invention does not exceed the national prescribed use dosage.

The preparation raw materials of the flavored milk comprise 0.17 to 0.65 percent of stabilizer based on the content of the raw material milk; the stabilizer preferably comprises an emulsifier and a thickener; the content of the emulsifier is preferably 0.16-0.3% of the mass of the preparation raw material, and more preferably 0.18-0.25%; the emulsifier preferably comprises one or more of glyceryl monostearate, sucrose fatty acid ester, molecular distillation monoglyceride, modified soybean phosphate and citric acid fatty acid ester; when the emulsifier comprises a plurality of emulsifiers, the mass ratio among the plurality of emulsifiers is not particularly limited, and the emulsifiers can be adjusted according to production requirements; the content of the thickener is preferably 0.01-0.35% of the mass of the preparation raw material, and more preferably 0.02-0.20%; the thickener preferably comprises one or more of microcrystalline cellulose, sodium carboxymethyl cellulose, carrageenan, acacia and guar gum; when a plurality of thickeners are included, the mass ratio between the plurality of thickeners is not particularly limited, and may be adjusted according to production requirements. The stabilizer composed of the emulsifier and the thickener with the content can ensure that the materials are mixed uniformly in production, the quality is stable within the quality guarantee period, and the situations of protein flocculation and the like are avoided.

The preparation raw materials of the flavored milk comprise 0.01 to 0.06 percent of buffer salt, and more preferably 0.03 to 0.04 percent of buffer salt by taking the content of the raw material milk as a reference; the buffer salt preferably comprises one or more of sodium hexametaphosphate, sodium tripolyphosphate, dipotassium hydrogen phosphate and sodium bicarbonate, more preferably one or more of sodium hexametaphosphate, dipotassium hydrogen phosphate and sodium bicarbonate; when a plurality of buffer salts are included, the mass ratio between the plurality of buffer salts is not particularly limited, and may be adjusted conventionally according to the preparation requirements. The buffer salt can adjust the pH value of a preparation system, so that the buffer salt has a good and stable system, and the problem of milk protein denaturation caused by adding fruit juice concentrate is avoided.

The flavored milk of the invention preferably further comprises other flavoring substances and/or pigments, wherein the addition amount of the other flavoring substances or pigments does not exceed the national standard limit, and the specific addition amount is required to be added for preparation.

The total mass of the preparation raw materials of the flavored milk is calculated as 100 percent, except the raw material milk, the fruit concentrated juice, the sweetener, the stabilizer and the buffer salt, the rest is water; when other flavors and/or colors are present, the content of other flavors or colors is subtracted from the water.

degreasing raw milk to obtain skimmed milk and cream;

performing membrane filtration treatment on the skim milk to obtain filtrate;

The invention performs degreasing treatment on raw milk to obtain skimmed milk and cream. When the raw milk is raw milk, the method preferably further comprises concentrating raw milk before the degreasing treatment; the concentration treatment mode preferably comprises reverse osmosis membrane concentration, falling film concentration or flash evaporation; specific operation steps of reverse osmosis membrane concentration, falling film concentration or flash evaporation are not particularly limited, and conventional operation steps in the field are adopted; the multiple of the concentration treatment is preferably 1.3 to 2.0 times, preferably 1.3 to 1.5 times; the temperature of the concentration treatment is preferably 4-55 ℃, and more preferably 10-50 ℃; the concentration treatment has the effects of improving physical and chemical indexes of the product and enriching the mouthfeel of the product.

The degreasing treatment according to the present invention preferably includes a centrifugal degreasing treatment of the raw milk, and the temperature of the centrifugal degreasing treatment is preferably 40 to 50 ℃, and more preferably 45 to 50 ℃. The other conditions for the centrifugal degreasing treatment are not particularly limited, and those conventional in the art may be used. The fat content in the skim milk obtained by the degreasing treatment of the invention is preferably less than or equal to 0.5%.

After the skim milk is obtained, the skim milk is subjected to membrane filtration treatment to obtain filtrate. The membrane filtration treatment of the invention is to separate milk components by utilizing the separability of the membrane, and select a proper membrane pore diameter, thereby playing a role in effectively removing bacteria and spores in milk according to the interception performance. Thus, for sterilization purposes, the membrane filtration treatment of the present invention preferably employs a Microfiltration (MF) treatment, which preferably employs an inorganic ceramic membrane; the pore diameter of the membrane filtration treatment is preferably 0.8 μm to 1.4 μm, more preferably 1.0 μm to 1.2 μm; the temperature is preferably 45 to 55℃and more preferably 50 ℃.

After the filtrate is obtained, the filtrate, the fruit concentrated juice, the sweetener, the stabilizer, the buffer salt and the water are subjected to first mixing at the temperature of 40-50 ℃ to obtain a mixed material. When pigments and/or other flavors are included in the preparation, the pigments and/or other flavors are preferably mixed with the filtrate along with fruit juice concentrate, sweetener, stabilizer, buffer salt, and water. The specific step of the first mixing is not particularly limited, and a conventional mixing method in the art may be adopted. The temperature of the first mixing is preferably 45-50 ℃; the time is 10 to 20 minutes, more preferably 15 to 20 minutes; the mixing temperature of the invention has the function of fully mixing materials under the condition of reducing the loss of active substances. The first mixing process is accompanied by stirring so as to fully and uniformly stir the materials, and the stirring mode and parameters are not particularly limited and can be set conventionally according to the needs.

The method carries out first sterilization treatment on the cream to obtain sterilized cream. The temperature of the first sterilization treatment is 120-157 ℃, preferably 137-145 ℃; the time of the first sterilization treatment is preferably 0.09 to 15 seconds, more preferably 2 to 4 seconds; the first sterilization treatment can effectively remove bacteria in the cream.

In the present invention, the process of membrane filtration treatment and first mixing of the skim milk is not in sequence with the process of first sterilization treatment of the cream.

After the mixed material and the sterilized cream are obtained, the mixed material and the sterilized cream are subjected to secondary mixing, and the flavored milk is obtained through homogenization treatment and secondary sterilization treatment. In the present invention, when the mixed material and the sterilized cream are subjected to the second mixing, the amount of the sterilized cream to be added is preferably selected according to the index content of protein and fat in the target product, and preferably, the whole sterilized cream is mixed with the mixed material, or a part of the sterilized cream is mixed with the mixed material, and the mass of the part of the sterilized cream is preferably 50% to 80%, more preferably 60% to 70% of the mass of the sterilized cream. The second mixing process is not particularly limited, and conventional mixing processes in the art may be employed. The temperature of the homogenization treatment is preferably 55-65 ℃, and more preferably 60-65 ℃; the pressure is preferably 18 to 30MPa, more preferably 22 to 28MPa. The temperature of the second sterilization treatment is preferably 72-75 ℃; the time is preferably 15 to 20 seconds. The flavored milk of the present invention is preferably refrigerated.

The flavored milk has higher protein content, certain immunoglobulin and lactoferrin content, and longer shelf life.

The technical solutions provided by the present invention are described in detail below in conjunction with examples for further illustrating the present invention, but they should not be construed as limiting the scope of the present invention.

In the present invention, the reagents and materials used are all conventionally commercially available, unless otherwise specified.

In the following examples:

raw milk was purchased from the company gmbh;

the thickener and emulsifier are purchased from Sibikeke, denmark (China) and Fuman (China) investment Co., ltd;

other materials and equipment not specifically described are available in conventional commercial sources;

protein content, immunoglobulin IgG content, lactoferrin content detection methods used in the examples are described in: T/CSCA 110059-2023 pasteurized milk-fresh milk.

Example 1

A flavored milk and its preparation method, the scheme is as follows:

1. raw material formula

Table 1 raw material formulation of example 1

2. Preparation method

(1) Preheating raw milk (protein 2.9% and fat 3.1%) to 45 ℃, and performing centrifugal degreasing treatment on the raw milk to obtain skimmed milk (fat less than or equal to 0.5%) and cream (fat more than or equal to 35%);

(2) Preheating the skim milk obtained in the step (1), raising the temperature to 45 ℃, and filtering by a 0.8 mu m ceramic membrane to obtain filtrate which is feed liquid A;

(3) Adding the feed liquid A obtained in the step (2) into watermelon concentrated juice (solid content is 65%), white granulated sugar, carrageenan, mono-diglycerol fatty acid ester, sucrose fatty acid ester and sodium bicarbonate, preserving heat at 45 ℃ and mixing for 15min to obtain feed liquid B;

(4) Sterilizing the cream obtained in the step (1) at 120 ℃ for 15 seconds to obtain sterilized cream which is feed liquid C;

(5) Uniformly mixing the feed liquid B, the feed liquid C and water with the total concentration of 100%, heating to 55 ℃, homogenizing at 18MPa, sterilizing at 72 ℃ for 15 seconds after homogenizing, cooling to below 6 ℃ after sterilizing, and canning to obtain the product.

3. Product detection results

After the products were tested, the test results are shown in table 2:

TABLE 2 detection results of the products prepared in example 1

Example 2

A flavored milk and its preparation method, the scheme is as follows:

1. raw material formula

Table 3 raw material formulation of example 2

Raw materials	Additive amount (%) (by weight)
		Raw milk	85
Erythritol	3
		Sucralose	0.01
Strawberry concentrated juice	0.5
		Molecular distillation of monoglycerides	0.12
Sucrose fatty acid ester	0.06
		Microcrystalline cellulose	0.3
Sodium carboxymethyl cellulose	0.05
		Sodium hexametaphosphate	0.03
Adding water to	100

2. Preparation method

(1) Performing RO reverse osmosis concentration on raw milk (protein 3.1% and fat 3.6%), concentrating at a concentration temperature of 1.5 times and 10 ℃ to obtain concentrated milk (protein 4.6% and fat 5.4%), preheating to 45 ℃, and performing centrifugal degreasing treatment to obtain skimmed milk (fat less than or equal to 0.5%) and cream (fat more than or equal to 40%);

(2) Preheating the skim milk obtained in the step (1), heating to 50deg.C, and filtering with 1.4 μm ceramic membrane to obtain filtrate as feed liquid A

(3) Adding the concentrated strawberry juice (solid content 40% and pH 3.5), erythritol, sucralose, molecular distillation monoglyceride, sucrose fatty acid ester, microcrystalline cellulose, sodium carboxymethylcellulose, sodium hexametaphosphate into the feed liquid A obtained in the step (2), maintaining the temperature at 50 ℃, and mixing for 20min to obtain a feed liquid B;

(4) Performing high-temperature sterilization for 4 seconds at the temperature of 137 ℃ on the cream obtained in the step (1) to obtain sterilized cream which is feed liquid C;

(5) Uniformly mixing the feed liquid B, 50wt.% of feed liquid C and water which is added with 100%, heating to 60 ℃, homogenizing at 22MPa, sterilizing at 75 ℃ for 15 seconds after homogenizing, cooling to below 6 ℃ after sterilizing, and canning to obtain the product.

3. Product detection results

After the products were tested, the test results are shown in Table 4:

TABLE 4 detection results of the products prepared in example 2

Project	Index (I)
		Proteins	3.9％
Fat	2.7％
		Immunoglobulin IgG	75mg/L
Lactoferrin protein	34mg/L
		Shelf life of the beverage	21 days

Example 3

A flavored milk and its preparation method, the scheme is as follows:

1. raw material formula

Table 5 raw material formulation of example 3

Raw materials	Additive amount (%) (by weight)
		Raw milk	50
High fructose syrup	2
		Apple juice concentrate	0.5
Peach concentrated juice	4.5
		Molecular distillation of monoglycerides	0.12
Sucrose fatty acid ester	0.06
		Acacia gum	0.14
Guar gum	0.06
		Dipotassium hydrogen phosphate	0.03
Sodium bicarbonate	0.03
		Adding water to	100

2. Preparation method

(1) Preheating raw milk (protein 3.6%, fat 4.0%) to 45deg.C, and centrifuging to obtain skimmed milk (fat less than or equal to 0.3%) and cream (fat more than or equal to 35%)

(2) Preheating the skim milk obtained in the step (1), heating to 50deg.C, and filtering with 1.2 μm ceramic membrane to obtain filtrate as feed liquid A

(3) Adding apple juice concentrate (solid content is 55%, pH value is 5.9), peach juice concentrate (solid content is 42%), high fructose syrup, molecular distillation monoglyceride, sucrose fatty acid ester, acacia, guar gum, dipotassium hydrogen phosphate and sodium bicarbonate into the feed liquid A obtained in the step (2), and mixing for 20min at the temperature of 50 ℃ to obtain feed liquid B;

(4) Sterilizing the cream obtained in the step (1) at 157 ℃ for 0.09s to obtain sterilized cream which is feed liquid C;

(5) Uniformly mixing the feed liquid B, the feed liquid C and water with the total concentration of 100%, heating to 65 ℃, homogenizing at 30MPa, sterilizing at 75 ℃ for 20 seconds after homogenizing, cooling to below 6 ℃ after sterilizing, and canning to obtain the product.

3. Product detection results

After the products were tested, the test results are shown in Table 6:

TABLE 6 detection results of the products prepared in example 3

Project	Index (I)
		Proteins	1.8％
Fat	2.0％
		Immunoglobulin IgG	58mg/L
Lactoferrin protein	20mg/L
		Shelf life of the beverage	21 days

Example 4

A flavored milk and its preparation method, the scheme is as follows:

1. raw material formula

Table 7 raw material formulation of example 4

2. Preparation method

(1) Taking raw milk (4.0% of protein and 4.6% of fat), performing falling film concentration, concentrating at 1.3 times, wherein the concentration temperature is 50 ℃, obtaining concentrated milk (5.2% of protein and 5.9% of fat), and performing centrifugal degreasing treatment to obtain skim milk (less than or equal to 0.5% of fat) and cream (more than or equal to 40% of fat);

(2) Preheating the skim milk obtained in the step (1), raising the temperature to 50 ℃, and filtering by a 1.4 mu m ceramic membrane to obtain filtrate which is feed liquid A.

(3) Adding apple juice concentrate (solid content of 55%, pH value of 5.9), pear juice concentrate (solid content of 40%, pH value of 6.2), stevioside, modified soybean phospholipid, citric acid fatty acid ester, carrageenan, sodium bicarbonate into the feed liquid A obtained in the step (2), keeping the temperature at 50 ℃, and mixing for 20min to obtain feed liquid B;

(4) Performing high-temperature sterilization at 145 ℃ for 2 seconds on the cream obtained in the step (1) to obtain sterilized cream which is feed liquid C;

(5) Uniformly mixing the feed liquid B, 60wt.% of feed liquid C and water which is added with 100%, heating to 60 ℃, homogenizing at 30MPa, sterilizing at 72 ℃ for 20 seconds after homogenizing, cooling to below 6 ℃ after sterilizing, and canning to obtain the product.

3. Product detection results

After the products were tested, the test results are shown in Table 8:

TABLE 8 detection results of the products prepared in example 4

Project	Index (I)
		Proteins	3.9％
Fat	2.7％
		Immunoglobulin IgG	25mg/L
Lactoferrin protein	16mg/L
		Shelf life of the beverage	For 15 days

Example 5

A flavored milk and its preparation method, the scheme is as follows:

1. raw material formula

Table 9 raw material formulation of example 5

Raw materials	Additive amount (%) (by weight)
		Raw milk	85
Erythritol	2.2
		Fructose	1.8
Concentrated juice of pear	1.5
		Apple juice concentrate	2
Fatty acid esters of mono-and diglycerides	0.15
		Sucrose fatAcid esters	0.15
Microcrystalline cellulose	0.3
		Sodium carboxymethyl cellulose	0.05
Sodium bicarbonate	0.04
		Mixed fruit essence	0.03
Adding water to	100

2. Preparation method

(1) Concentrating raw milk (protein 3.1% and fat 3.5%) by RO (reverse osmosis) at a concentration temperature of 2.0 times and 10 ℃ to obtain concentrated milk (protein 6.2% and fat 7.0%), preheating to 50 ℃ and performing centrifugal degreasing treatment to obtain skimmed milk (fat less than or equal to 0.5%) and cream (fat more than or equal to 38%);

(2) Preheating the skim milk obtained in the step (1), raising the temperature to 50 ℃, and filtering by a 0.8 mu m ceramic membrane to obtain filtrate which is feed liquid A.

(3) Adding apple juice concentrate (solid content is 55%, pH value is 5.9), pear juice concentrate (solid content is 40%, pH value is 6.2), erythritol, fructose, mono-diglycerol fatty acid ester, sucrose fatty acid ester, microcrystalline cellulose, sodium carboxymethyl cellulose, sodium bicarbonate and mixed fruit essence 0.03%, maintaining the temperature at 50 ℃ and mixing for 15min to obtain feed liquid B;

(5) Uniformly mixing the feed liquid B, 80wt.% of feed liquid C and water which is added with 100%, heating to 60 ℃, homogenizing at 30MPa, sterilizing at 72 ℃ for 20 seconds, cooling to below 6 ℃ after sterilizing, and canning to obtain the product.

3. Product detection results

After the products were tested, the test results are shown in Table 10:

TABLE 10 detection results of the products prepared in example 5

Project	Index (I)
		Proteins	5.3％
Fat	4.8％
		Immunoglobulin IgG	28mg/L
Lactoferrin protein	19mg/L
		Shelf life of the beverage	For 15 days

Comparative example 1

A flavored milk and its preparation method, the scheme is as follows:

1. the raw material formulation is the same as in example 1;

2. preparation method

(1) Step 1 as in example 1;

(2) Adding watermelon concentrated juice (solid content is 65%), white granulated sugar, carrageenan, mono-diglycerol fatty acid ester, sucrose fatty acid ester and sodium bicarbonate into the skim milk obtained in the step (1), and mixing for 15min at the temperature of 45 ℃ to obtain a feed liquid B;

(3) Step 4 as in example 1;

(4) Step 5 is the same as in example 1.

After the products were tested, the test results are shown in Table 11:

TABLE 11 detection results of the products prepared in comparative example 1

Project	Index (I)
		Proteins	2.5％
Fat	1.3％
		Immunoglobulin IgG	42mg/L
Lactoferrin protein	22mg/L
		Shelf life of the beverage	For 10 days

It can be derived from a combination of tables 2 and 11: in comparison with example 1, comparative example 1 was not subjected to preheating of skim milk and ceramic membrane filtration sterilization treatment, but the content of immunoglobulin IgG as an active substance in the obtained product was comparable to that in example 1, but the content of lactoferrin was slightly reduced, and most importantly, the shelf life of comparative example 1 was greatly affected by 9 days on the basis of not being subjected to sterilization treatment.

Comparative example 2

A flavored milk and its preparation method, the scheme is as follows:

1. the raw material formulation is the same as in example 1;

2. preparation method

(1) Step 1 as in example 1;

(2) Step 2 as in example 1;

(3) Adding the feed liquid A obtained in the step (2) into watermelon concentrated juice (solid content is 65%), white granulated sugar, carrageenan, mono-diglycerol fatty acid ester, sucrose fatty acid ester and sodium bicarbonate, maintaining the temperature at 70 ℃, and mixing for 15min to obtain feed liquid B; the method comprises the steps of carrying out a first treatment on the surface of the

(4) Step 4 as in example 1;

(5) Step 5 is the same as in example 1.

After the products were tested, the test results are shown in Table 12:

table 12 results of detection of the products prepared in comparative example 2

Project	Index (I)
		Proteins	2.5％
Fat	1.3％
		Immunoglobulin proteinIgG	Not detected
Lactoferrin protein	Not detected
		Shelf life of the beverage	For 19 days

The results of table 2 and table 12 combined show that: compared with the example 1, the mixing temperature of the feed liquid A, the watermelon juice concentrate, the white granulated sugar, the carrageenan, the mono-glycerol fatty acid ester, the diglycerol fatty acid ester, the sucrose fatty acid ester and the sodium bicarbonate is improved in the comparative example 2, and the quality guarantee period of the prepared product is ensured, but the immunoglobulin IgG and the lactoferrin in the prepared product are inactivated.

Comparative example 3

A flavored milk and its preparation method, the scheme is as follows:

1. the raw material formulation is the same as in example 1;

2. preparation method

(1) Step 1 as in example 1;

(2) Step 2 as in example 1;

(3) Step 3 as in example 1;

(4) Sterilizing the cream obtained in the step (1) at 95 ℃ for 15 seconds to obtain sterilized cream which is feed liquid C;

(5) Step 5 is the same as in example 1.

After the products were tested, the test results are shown in Table 13:

TABLE 13 detection results of the products prepared in comparative example 3

Project	Index (I)
		Proteins	2.5％
Fat	1.3％
		Immunoglobulin IgG	Not detected
Lactoferrin protein	Not detected
		Shelf life of the beverage	For 7 days

As can be seen from the results of table 2 and 13, comparative example 3 lowered the sterilization temperature for cream, compared with example 1, so that the shelf life of the prepared product was too short and no active substance was detected.

Comparative example 4

A flavored milk and its preparation method, the scheme is as follows:

1. the raw material formulation is the same as in example 1;

2. preparation method

(1) Step 1 as in example 1;

(2) Step 2 as in example 1;

(3) Step 3 as in example 1;

(4) Step 4 of example 1

(5) Mixing the feed liquid B, part of feed liquid C and water with the total concentration of 100%, heating to 55deg.C, homogenizing at 18MPa, sterilizing at 80deg.C for 15s, cooling to below 6deg.C, and canning.

After the product was tested, the test results are shown in Table 14:

table 14 results of detection of the products prepared in comparative example 4

As can be seen from a combination of the results in table 2 and table 14, comparative example 4 increased the homogenization temperature in step (5) and increased the shelf life of the product to 6 days, but no immunoglobulin IgG or lactoferrin was detected, as compared with example 1.

In summary, the embodiment of the invention not only shows that the active substances have good shelf life, but also has good shelf life performance due to the fact that the shelf life is possibly prolonged but the active substances cannot be reserved or the active substances with higher content are reserved but the shelf life is too short due to different sterilization treatment temperatures in the comparative example, so that the invention overcomes the defects of the prior art, has the active substances and good shelf life performance, and has high industrial utilization value.

Although the foregoing embodiments have been described in some, but not all, embodiments of the invention, it should be understood that other embodiments may be devised in accordance with the present embodiments without departing from the spirit and scope of the invention.

Claims

1. The flavored milk is characterized by comprising the following raw materials in percentage by mass:

2. A flavored milk according to claim 1, wherein the fruit juice concentrate has a soluble solids content of 40% to 60% and a pH of 3.5 to 6.2.

3. A flavored milk according to claim 1, wherein the sweetener comprises one or more of white sugar, fructose, erythritol, fructose syrup, sucralose, and steviol glycosides.

4. Flavored milk according to claim 1, wherein the stabilizing agent comprises an emulsifier and a thickener; the content of the emulsifying agent is 0.16-0.3% of the mass of the preparation raw material; the content of the thickener is 0.01-0.35% of the mass of the preparation raw material;

the emulsifier comprises one or more of glycerin monostearate, sucrose fatty acid ester, molecular distillation monoglyceride, modified soybean phosphate and citric acid fatty acid ester;

the thickener comprises one or more of microcrystalline cellulose, sodium carboxymethyl cellulose, carrageenan, acacia and guar gum.

5. A flavored milk according to claim 1, wherein the buffer salt comprises one or more of sodium hexametaphosphate, sodium tripolyphosphate, dipotassium hydrogen phosphate, and sodium bicarbonate.

6. A method of preparing flavored milk according to any one of claims 1 to 5, comprising the steps of:

degreasing raw milk to obtain skimmed milk and cream;

performing membrane filtration treatment on the skim milk to obtain filtrate;

7. The method according to claim 6, wherein the membrane filtration treatment has a membrane pore size of 0.8 μm to 1.4 μm and a temperature of 45℃to 55 ℃.

8. The method according to claim 6, wherein the time of the first sterilization treatment is 0.09 to 15 seconds; the first mixing time is 10-20 min.

9. The method according to claim 6, wherein the temperature of the homogenizing treatment is 55 to 65 ℃ and the pressure is 18 to 30MPa; the temperature of the second sterilization treatment is 72-75 ℃ and the time is 15-20 s.

10. The method according to claim 6, wherein the method further comprises concentrating the raw milk before degreasing, wherein the concentration is performed at a temperature of 4-55 ℃ by a factor of 1.3-2.0; the degreasing treatment comprises centrifugal degreasing treatment, wherein the temperature of the centrifugal degreasing treatment is 40-55 ℃.