WO2021031348A1 - Milk-based liquid infant formula containing active proteins, and preparation method therefor - Google Patents

Abstract

A milk-based liquid infant formula containing active proteins, preparation method therefor, and a use of the preparation method. Fresh milk is used as a main raw material. According to requirements of the national standard and the standard of breastmilk, the proportions of the protein, fat, and carbohydrate in the milk are regulated; a vitamin and a mineral substance are added; and by means of the comparison of the effects of different heat treatment processes on active proteins in the milk, which mainly comprise immunoglobulins, lactoferrins, and low-abundance proteins in milk serum, the pasteurization method is finally used to sterilize the milk, such that a pasteurized milk-based liquid infant formula having active proteins is developed.

Description

Milk-based infant formula liquid milk containing active protein and preparation method thereof Technical field

The invention relates to a milk-based infant formula liquid milk containing active protein and a preparation method thereof, and belongs to the technical field of dairy products.

Background technique

At present, most of the infant formula milk on the market exists in the form of milk powder, and a small part is in the form of liquid milk stored at room temperature after ultra-high temperature sterilization. In the process of converting fresh milk into formula milk powder or formula liquid milk stored at room temperature, many heat treatment operations will cause the heat-sensitive active protein in the milk to denature and lose its biological activity, such as lactoferrin and immunoglobulin , Lactagglutinin, Lactoperoxidase, etc. These active proteins often play an important role in enhancing the immunity of infants and young children, improving cognitive ability, enhancing physical fitness, and reducing the incidence of diseases such as asthma. The loss of these active proteins greatly reduces the nutritional value of milk, and the existing infants The processing methods of infant formula milk products can hardly retain these active proteins in fresh milk.

Modern nutrition recognizes that breast milk is the most ideal natural food for infants and young children, and it is also the gold standard for infant formula milk powder. However, due to work, health and other reasons, most mothers cannot guarantee normal breastfeeding. Therefore, infant formula milk powder represented by cow milk and goat milk has become the main diet and nutrition source for contemporary newborns.

However, the nutritional value of common infant formula milk powder or normal temperature infant formula liquid milk on the market cannot be compared with breast milk, because breast milk is naturally rich in immunologically active substances, such as immunoglobulins (including IgA, IgG and IgM, etc.), Lactoferrin, enzymes, and hundreds of low-abundance proteins, these low-abundance proteins often have life activities such as regulating immunity and promoting metabolism. As one of the important antibodies of human mucosal immunity, IgA plays an important role in protecting newborns from intestinal and respiratory pathogenic microbial infections (Hanson and Korotkova, 2002). IgG and IgM also play an important role in the defense of the intestinal mucosa of infants. IgG can bind to viruses to lure pathogens or prevent them from adhering to the mucosal surface (Robert-Guroff, 2000). At this stage, infant formula powder generally can only simulate breast milk as much as possible in terms of macronutrients, such as adjusting the ratio of casein to whey protein, and adjusting the types of fatty acids, but it is difficult for active proteins such as immunoglobulins and other important functions The level of low-abundance protein to simulate breast milk. Troost et al. (2001) and Jasion (2015) showed that lactoferrin and immunoglobulin in milk can avoid gastrointestinal digestion, and play a very important role in maintaining the body's antibacterial, anti-inflammatory, and enhancing immunity.

At this stage, heat treatment is the most common processing method in the processing of raw milk, and the processing and inactivation of active proteins in raw milk is an important problem in the current dairy industry. The lactoferrin and immunoglobulin in dairy products are often heat-sensitive. The preparation of infant formula powder often requires a series of high temperature treatments, such as sterilization, concentration, and spray drying. The normal temperature infant formula liquid milk also undergoes ultra-high temperature sterilization. In these heat treatment processes, the biological activity of the functional protein is almost completely lost, and a large number of low-abundance proteins in the whey are reduced, resulting in a greatly reduced nutritional value. Recently, Zhang Yanjie disclosed an infant formula milk powder containing lactoferrin and probiotics and its preparation method (publication number: CN108029768A), in which additional lactoferrin still needs to be added manually. Most of the commercially available lactoferrin is a purified imported product, which is extremely scarce and expensive, and it is prone to protein denaturation during the purification process, thereby losing its biological activity.

Therefore, how to develop an infant formula liquid milk that is convenient to drink and contains active protein and its preparation method is an important problem to be solved urgently in this field.

Technical solutions

The purpose of the present invention is to provide a method for preparing milk-based liquid formula milk for infants and young children containing active protein. The preparation method includes mixing, homogenizing, and heat sterilizing liquid fresh milk or goat milk with other nutrients. Heat sterilization treatment is to use pasteurization at 72～75 ℃ for 15～20 s or 63～65 ℃ for 30～40 min.

In one embodiment of the present invention, the preparation method includes the following steps:

(1) Take fresh milk or goat milk and determine the content of protein, lactose, fat and minerals;

(2) Calculate the required nutrient content in infant formula liquid milk in accordance with the national food safety standard GB 10765-2010;

(3) Mix whey protein powder, plant blended oil, lactose, phospholipids, DHA and ARA with purified water to dissolve it, stir thoroughly and mix with fresh milk or goat milk evenly, so that the resulting mixture contains whey protein powder, The content of plant blend oil, lactose, phospholipid, DHA and ARA meet the calculation results in step (2);

(4) Dissolve the compound mineral premix and compound vitamin premix with purified water respectively, add step by step to the mixture obtained in step (3) and mix thoroughly, add compound minerals and compound vitamins When the mixing time is not less than 15 minutes, add inositol, choline, and taurine and mix thoroughly so that the resulting mixture is compounded with minerals, compound vitamins, inositol, choline, and taurine The content meets the calculation result in step (2);

(5) Homogenization;

(6) Sterilize the homogenized liquid milk, use pasteurization at 72～75 ℃ for 15～20 s or 63～65 ℃ for 30～40 min.

In one embodiment of the present invention, the active protein refers to lactoferrin, immunoglobulin IgG, IgA, IgM, lactoperoxidase, complement protein C3, ribonuclease, lipocalin-2 , Lactagglutinin or its combination.

In one embodiment of the present invention, the nutrients include whey protein powder, vegetable oil, lactose, phospholipids, DHA, ARA, compound minerals and compound vitamins.

In one embodiment of the present invention, step (1) determines the content of minerals in cow milk or goat milk by inductively coupled plasma mass spectrometry ICP-MS.

In one embodiment of the present invention, the whey protein powder is added to make the ratio of whey protein to casein in milk ≥3: 2, the ratio of protein in milk is close to the ratio of protein in breast milk, and the total protein content is 1.0～2.5 g/100 mL.

In an embodiment of the present invention, the temperature of the purified water in step (3) and step (4) is 40-50°C.

In one embodiment of the present invention, the whey protein powder, vegetable oil, minerals, vitamins, inositol, choline, taurine, DHA and ARA required to be added to the formula milk meet the national food safety standard GB The standard specified by 10765-2010.

In one embodiment of the present invention, the homogenization condition is 20-30 MPa, homogenize for 1 to 2 times.

In one embodiment of the present invention, after sterilization, aseptic filling, cold chain transportation or low temperature refrigeration.

Another object of the present invention is to provide infant formula milk prepared by the above-mentioned milk-based infant formula liquid milk preparation method with improved active protein retention rate.

Another object of the present invention is to provide the application in the food field of the method for preparing milk-based infant liquid formula milk for improving the retention of active protein.

Beneficial effect

The present invention uses fresh milk (bovine milk or goat milk) as the main raw material, adjusts the ratio of protein, fat and carbohydrate in the milk, and adds vitamins and minerals to better simulate the breast milk formula. In addition, the present invention compares the effects of different heat treatment processes on the active protein in milk, and finally selects the pasteurization method to complete the sterilization of the milk, thereby developing a pasteurized infant liquid formula with active protein .

Description of the drawings

Figure 1: (a) Preparation process of liquid infant formula milk and (b) experimental process of liquid mass protein group (LC-MS/MS).

Figure 2: The effect of different heat treatment methods on the retention of active protein in fresh milk.

Figure 3: The effect of different heat treatment methods on the retention of active protein in fresh goat milk.

Figure 4: Electrophoresis patterns of whey protein in fresh milk after different heat treatments.

Figure 5: Heat map (A) and principal component analysis map (B) of whey protein group in infant formula liquid milk after different heat treatment.

Figure 6: Volcano graph of whey protein group in samples of high temperature treatment group (E, U, S) and low temperature treatment group (L, H) (p<0.05).

Embodiments of the invention

The embodiments of the present invention are intended to better explain the invention and do not limit the scope of protection of the present invention. Those skilled in the art should know that the present invention can be implemented without error according to the steps in the description of the present invention. If there is a slight difference in the retention rate of active protein due to different milk sources (such as non-fresh milk and milk producing areas), it should not be used as a reason for inconsistent technical solutions of the present invention.

The liquid infant formula milk preparation process and the liquid mass protein group (LC-MS/MS) experimental process are shown in Figure 1.

Example 1

A milk-based liquid formula for older babies (6-12 months) containing active protein

Based on the nutritional requirements of infants from 6 to 12 months old, fresh milk, whey protein powder, vegetable oil, lactose are used as the main raw materials, and multivitamins, minerals, taurine, inositol, choline, etc. are added. In terms of weight percentage, it includes the following components: 25% fresh milk, 0.95% whey protein powder, 5.75% lactose, 2.58% vegetable blend oil (in terms of mass percentage, including the following raw material components: soybean oil 45%, corn oil 40 %, canola oil 5%, high oleic sunflower oil 5%, coconut oil 5%), compound mineral 0.13% (based on mass percentage, including the following raw material components: anhydrous copper sulfate 0.62% , Potassium iodate 5.40%, ferrous sulfate 16.86%, magnesium sulfate 49.35%, zinc sulfate 7.33%), compound vitamin 0.48% (by mass percentage, including the following raw material components: retinyl acetate 1.23%, cholecalcification Alcohol 0.71%, alpha-tocopherol acetate 4.58%, plant menadione 0.16%, thiamine nitrate 0.15%, riboflavin 0.07%, pyridoxine hydrochloride 0.12%, L-sodium ascorbate 66%, D-calcium pantothenate 0.62%, D-biotin 0.31%, folic acid 0.17%, nicotinamide 0.94%, cyanocobalamin 0.31%, lutein 0.94%), docosahexaenoic acid (DHA) 0.18% (based on pure product), arachidonic acid (ARA) 0.22% (calculated as pure product), 0.015% choline and purified water.

It mainly includes the following steps:

Step 1: Take fresh milk and measure the protein, lactose, milk fat and minerals in the milk;

Step 2: Calculate the content of macronutrients in infant formula milk based on the nutrient requirements of infants aged 6-12 months;

Step 3: Use 40-50 for whey protein powder, vegetable oil, lactose, phospholipids, DHA and ARA Mix and dissolve in pure water at ℃ and stir thoroughly;

Step 4: Dissolve the compound mineral premix and compound vitamin premix in each special container with purified water at 40～50℃, and add them step by step to the mixture of step 1 for thorough mixing and compounding The time for adding and mixing minerals and compound vitamins should be ≥15min, then add inositol, choline, and taurine and mix thoroughly;

Step 5: Homogenization: homogenize the above-mentioned mixture at a homogenization pressure of 25-30 MPa, homogenize 1 to 2 times;

Step 6: Sterilize the homogenized liquid milk (75°C, 15s);

Step 7: Cold chain transportation after aseptic filling, low temperature storage (under 4℃).

Example 2

A kind of milk-based liquid formula milk for children (12-24 months) containing active protein

Based on the nutritional requirements of children aged 12 to 24 months, fresh milk, whey protein powder, vegetable oil, lactose are used as the main raw materials, and multi-vitamins, minerals, taurine, inositol, choline, etc. are added. In terms of weight percentage, it includes the following components: 25% fresh milk, 1.35% whey protein powder, 8.35% lactose, 2.28% vegetable blend oil (by mass percentage, including the following raw material components: soybean oil 45%, corn oil 40 %, canola oil 5%, high oleic sunflower oil 5%), compound mineral 0.13% (calculated by mass percentage, including the following raw materials: anhydrous copper sulfate 0.62%, potassium iodate 5.40 %, ferrous sulfate 16.86%, magnesium sulfate 49.35%, zinc sulfate 7.33%), compound vitamin 0.48% (by mass percentage, including the following raw material components: retinyl acetate 1.23%, cholecalciferol 0.71%, α -Tocopherol acetate 4.58%, plant menadione 0.16%, thiamine nitrate 0.15%, riboflavin 0.07%, pyridoxine hydrochloride 0.12%, L-sodium ascorbate 66%, D-calcium pantothenate 0.62%, D- Biotin 0.31%, folic acid 0.17%, nicotinamide 0.94%, cyanocobalamin 0.31%, lutein 0.94%), docosahexaenoic acid (DHA) powder 0.18%, arachidonic acid (ARA) powder 0.22 %, Choline 0.015% and purified water.

It mainly includes the following steps:

Step 1: Take fresh milk and measure the protein, lactose, milk fat and minerals in the milk;

Step 2: Calculate the content of macronutrients in infant formula milk based on the nutrient requirements of infants aged 6-12 months;

Step 3: Use 40-50 for whey protein powder, vegetable oil, lactose and phospholipids Mix and dissolve in pure water at ℃ and stir thoroughly;

Step 4: Use 40-50 compound mineral premix and compound vitamin premix in each special container respectively Dissolve in pure water at ℃, add step by step to the mixture of step 1 and mix thoroughly. The mixing time for compound minerals and compound vitamins should be ≥15min, and then add inositol, choline, taurine, DHA and ARA , Fully mixed;

Step 5: Homogenization: homogenize the above-mentioned mixture at a homogenization pressure of 20-30 MPa, homogenize 1-2 times;

Step 6: Sterilize the homogenized liquid milk (75°C, 15s);

Step 7: Cold chain transportation after aseptic filling, low temperature storage (under 4℃).

Example 3

A goat milk-based liquid formula for older babies (6-12 months) containing active protein

Based on the nutritional requirements of infants from 6 to 12 months old, fresh goat milk, whey protein powder, vegetable oil, lactose are used as the main raw materials, and multivitamins, minerals, taurine, inositol, choline, etc. are added. In terms of weight percentage, it includes the following components: 25% fresh goat milk, 0.95% whey protein powder, 5.75% lactose, 2.58% vegetable blend oil (by mass percentage, including the following raw material components: soybean oil 45%, corn oil 40%, canola oil 5%, high oleic sunflower oil 5%, coconut oil 5%), compound mineral 0.13% (based on mass percentage, including the following raw material components: anhydrous copper sulfate 0.62 %, potassium iodate 5.40%, ferrous sulfate 16.86%, magnesium sulfate 49.35%, zinc sulfate 7.33%), compound vitamin 0.48% (by mass percentage, including the following raw material components: retinyl acetate 1.23%, bile Calciferol 0.71%, alpha-tocopherol acetate 4.58%, plant menadione 0.16%, thiamine nitrate 0.15%, riboflavin 0.07%, pyridoxine hydrochloride 0.12%, L-sodium ascorbate 66%, D-pantothenic acid Calcium 0.62%, D-biotin 0.31%, folic acid 0.17%, nicotinamide 0.94%, cyanocobalamin 0.31%, lutein 0.94%), docosahexaenoic acid (DHA) 0.18% (based on pure product), arachidonic acid (ARA) 0.22% (calculated as pure product), 0.015% choline and purified water.

It mainly includes the following steps:

Step 1: Take fresh goat milk and measure the protein, lactose, milk fat and minerals in the milk;

Step 2: Calculate the content of macronutrients in liquid milk formula for infants and young children based on the nutrient requirements of infants aged 6-12 months;

Step 3: Use 40-50 for whey protein powder, vegetable oil, lactose, phospholipids, DHA and ARA Mix and dissolve in pure water at ℃ and stir thoroughly;

Step 4: Dissolve the compound mineral premix and compound vitamin premix in each special container with purified water at 40～50℃, and add them step by step to the mixture of step 1 for thorough mixing and compounding The time for adding and mixing minerals and compound vitamins should be ≥15min, then add inositol, choline, and taurine and mix thoroughly;

Step 5: Homogenization: homogenize the above-mentioned mixture at a homogenization pressure of 25-30 MPa, homogenize 1 to 2 times;

Step 6: Sterilize the homogenized liquid milk (65°C, 30min);

Step 7: Cold chain transportation after aseptic filling, low temperature storage (under 4℃).

Example 4

Taking the infant liquid formula obtained in Example 1 as an example, the enzyme-linked immunoassay method was used to compare the immunoglobulin (IgA, IgG and IgM) and lactoferrin content in infant formula produced by different processes, and SDS was used at the same time. -Gel electrophoresis and LC-MS/MS proteomics methods to identify the types and content changes of low-abundance proteins in whey protein. The specific test process and result analysis are as follows:

(1) Experimental materials, reagents and instruments

Fresh milk was purchased from Wuxi Tianzi Dairy Co., Ltd., Jiangsu Province, and the immunoglobulin test kit (Elisa Kit) was purchased from Bethyl Company, USA. The liquid chromatography used for LC-MS/MS was from USA Thermo Fisher Scientific Ultimate 3000 capillary high performance liquid chromatograph, mass spectrometer is Thermo Fisher Scientific Q Exactive Electrospray-Combined Ion Trap Orbitrap Mass spectrometer. All capillary liquid chromatography columns used are PepMap RPLC C18 prepacked column. Mobile phase A: 0.1% formic acid, 2% ACN; mobile phase B: 0.1% formic acid, 80% ACN; flow rate: 300 nL/min.

(2) Experimental process

Purchase 6 kinds of commercially available infant formula milk powder and normal temperature storage type infant formula liquid milk for the determination of immunoglobulin and lactoferrin content, and dissolve the milk powder in deionized water at the same mass fraction of solid content and then dilute , The liquid milk is directly diluted 500-1000 times (to ensure that it is within the detection range of the kit), and then the content of immunoglobulin and lactoferrin is determined.

Prepare fresh liquid infant formula samples (group R) according to Example 1, and perform different heat treatment processes for sterilization. Sterilization conditions were 65°C, 30min (L group), 75°C, 15s (H group), 125°C, 5s (E group), 135°C, 5s (U group) and spray drying (95°C sterilization for 15 minutes, spray Dry, inlet air temperature is 185°C, outlet air temperature is 85°C, S group). The samples of different treatment groups were subjected to ultra-high-speed centrifugation (Beckman, USA) Coulter centrifuge, 100000g, 25°C, 90min) After obtaining the whey, the immunoglobulin and lactoferrin content determination (two parallel holes for each sample), SDS gel electrophoresis experiment, trypsin digestion And LC-MS/MS Proteomics experiment (two parallels for each sample). The enzymolysis operation is as follows:

1) Transfer 100 μg of protein to a 10 kD ultrafiltration tube, add 50 mmol/L NH ₄ HCO ₃ solution to 200 μL, and centrifuge at 4 ℃ and 12000 rcf for 10 min.

2) Add 200 μL of 50 mmol/L NH ₄ HCO ₃ solution, centrifuge at 4 ℃ at 12000 rcf for 10 min, and repeat the operation twice until the solution becomes colorless and transparent.

3) Add 50 μL of 50 mmol/L NH ₄ HCO ₃ solution, add DTT solution to make the final concentration 10 mmol/L, and reduce in a 37 ℃ water bath for 4 h.

4) Add the IAA solution to make the final concentration 50 mmol/L, dark reaction 40 min after 4 °C at 12000 Centrifuge at rcf speed 10 min.

5) Add 100 μL of 50 mmol/L NH ₄ HCO ₃ solution and centrifuge at 12000 rcf for 10 min at 4 ℃.

6) Replace with a new cannula, add 50 μL of 50 mmol/L NH ₄ HCO ₃ solution to the ultrafiltration tube, add trypsin according to the mass ratio of trypsin to substrate 1:100, digest at 37 ℃ for 4 hours, continue Add pancreatin at a mass ratio of 1:100, and digest at 37°C overnight (16 h).

7) At 4 °C at 12000 Centrifuge at rcf speed 10 min, add 100 μL water, after vortexing, at 12000 at 4℃ Centrifuge at rcf speed 10 min, and repeat the operation once.

8) After digestion, the peptide fragments are desalted using self-packing desalting column. Evaporate the solvent in a vacuum centrifugal concentrator at ℃.

9) Dissolve the peptide with sample dissolving solution (0.1% formic acid, 2% acetonitrile), vortex thoroughly, 13200 rpm, 4 Centrifuge at ℃ 10 min, transfer the supernatant to the sample tube and wait for mass spectrometry analysis. Mass spectrometry parameters: Resolution: 70,000; AGCtarget: 3e6; MaximumIT: 40 ms; Scanrange: 350 to 1800 m/z;

Two-stage mass spectrometry parameters: Resolution: 75,000; AGCtarget: 1e5; MaximumIT: 60 ms;

TopN: 20; NCE/steppedNCE: 27. Mass spectrometry raw files use Maxquant (1.6.2.10) Search the uniprot-Bos taurus database, and use Uniprot data to search the biological functions of the identified proteins.

From Figure 2 and Figure 3, it can be seen that after different heat sterilization treatments, the retention rate of immune-related active protein in fresh milk is significantly different. The retention rate of active protein in milk after different heat treatments is based on that in fresh milk or goat milk. The protein content is calculated from the control. On the whole, the two pasteurization methods (L group and H group) have a higher retention rate of active protein, and after ESL (Extended Shelf Life, pasteurization to extend shelf life) Treatment (Group E), UHT (Ultra After High Temperature and UHT treatment (group U) and spray drying treatment (group S), the immunoglobulins in the milk were not detected, and the content was almost close to zero. Therefore, the heat treatment method adopted in the present invention is pasteurization, that is, 72-75°C, 15-20s or 63-65°C, 30-35min.

From Figure 4, it can be found that the types of whey protein in fresh milk have changed significantly after the treatment of E, U and S groups. Among them, the bands of lactoferrin, bovine serum albumin and heavy chain immunoglobulin have not been observed; in addition, the bands of α-lactalbumin and β-lactoglobulin are also reduced a lot, especially after UHT treatment after. Therefore, the present invention uses L or H heat treatment to sterilize the milk.

It can be found from Table 1 that compared with the initial mixed sample of liquid milk formula for infants and young children without heat treatment, the contents of immunoglobulin and lactoferrin in the final product of infant formula prepared by two pasteurizations decreased, but both A large degree of retention can be obtained; however, the samples of group H, group E and group S do not contain immunoglobulin and lactoferrin. At the same time, it can be found that 4 kinds of infant formula milk powders purchased from the market (respectively are China Yili Company Golden Collar Crown 1st paragraph, German Pronutra ⁺ Company Aptamil 2nd paragraph, Dutch Nutricia Company Nutrilon 1st paragraph, Irish Wyeth Company Qifu 2nd paragraph), 2 Two kinds of liquid milk formula for infants and young children at room temperature: Mead Johnson & Company imported from the United States (Mead Johnson & Company) Enfagrow infant formula milk, France imported from France (Synutra) Briveni infant formula liquid milk and 1 type of Dutch imported whole milk powder Dutch Cow) has been tested and found that no active immunoglobulin and lactoferrin can be detected. Therefore, the present invention adopts low-temperature heat sterilization to prepare liquid infant formula milk products.

Table 1 Comparison of immunoglobulin and lactoferrin content between milk-based infant formula samples with different treatment methods and 6 commercially available infant formula products

Note: Different letters in the same column represent significant differences (p<0.05), "-" means undetectable.

From the identified proteomic data, it can be found that the types of whey protein in the infant formula samples after different heat treatment have undergone great changes. From the principal component analysis graph, it can be found that the L group and the H group are clustered together and can hardly be distinguished, while the E, U and S groups are clustered together. In order to facilitate the analysis, the following experiments will classify L and H into the low-temperature treatment group, and classify E, U and S into the high-temperature treatment group for bioinformatics analysis.

It can be seen from Figure 5 and Figure 6 that after the high temperature group treatment, the content of heat-sensitive proteins in whey has changed significantly, among which complement protein C3, lactoferrin, folate receptor protein, lipocalin, etc. The content has dropped significantly. At the same time, the abundance of some proteins in the whey after high heat treatment, such as α-casein and β-casein, may be due to the disulfide bonds between these proteins in the whey protein during the heating process. Caused by cooperation.

Table 2 lists the low-abundance whey proteins that have decreased content and lack of loss after high temperature treatment. These proteins mainly include enzymes, complement proteins, structural proteins, etc., and involve many physiological activities such as catalysis, immunity, and adhesion. The results show that the liquid milk formula for infants and young children prepared by the heat treatment method of the present invention retains a higher content of active proteins, such as immunoglobulin, lactoferrin, complement protein, lactectin, etc.

Table 2 Comparison of protein content between high temperature treatment group and low temperature treatment group

Note: "-" means not applicable.

Although the present invention has been disclosed as above in preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. The protection scope of the present invention should be defined by the claims.

Claims (15)

1. A preparation method of milk-based infant formula liquid milk containing active protein, characterized in that, the preparation method comprises mixing, homogenizing, and heat sterilizing liquid fresh milk or goat milk with other nutrients. It is pasteurized at 72～75℃ for 15～20s or 63～65℃ for 30～40 min.
2. A preparation method of milk-based infant formula liquid milk containing active protein, characterized in that, the preparation method comprises mixing, homogenizing, and heat sterilizing liquid fresh milk or goat milk with other nutrients. It is pasteurized at 70～85 ℃ for 12～30s or 62.5～70℃ for 30～40 min.
3. The preparation method of milk-based infant formula liquid milk according to claim 1 or 2, wherein the preparation method comprises the following steps:

   (1) Take fresh milk or goat milk and determine the content of protein, lactose, fat and minerals;

   (2) According to the national food safety standard GB 10765-2010 Calculate the content of nutrients required in liquid milk formula for infants and young children;

   (3) Mix whey protein powder, plant blended oil, lactose, phospholipids, DHA and ARA with purified water to dissolve it, stir thoroughly and mix with fresh milk or goat milk evenly, so that the resulting mixture contains whey protein powder, The content of plant blend oil, lactose, phospholipid, DHA and ARA meet the calculation results in step (2);

   (4) Dissolve the compound mineral premix and compound vitamin premix with purified water respectively, add step by step to the mixture obtained in step (3) and mix thoroughly, add compound minerals and compound vitamins When the mixing time is not less than 15 minutes, add inositol, choline, and taurine and mix thoroughly so that the resulting mixture is compounded with minerals, compound vitamins, inositol, choline, and taurine The content meets the calculation result in step (2);

   (5) Homogenization;

   (6) Sterilize the homogenized liquid milk, and use pasteurization at 72～75℃ for 15～20s or 63～65℃ for 30～40 min.
4. The method for preparing milk-based infant formula liquid milk according to claim 3, wherein the step (1) determines the content of minerals in the milk by inductively coupled plasma mass spectrometry (ICP-MS).
5. The method for preparing milk-based infant formula liquid milk according to claim 3, wherein the whey protein powder is added so that the ratio of whey protein to casein in the milk is ≥3:2.
6. The method for preparing liquid milk-based infant formula milk according to claim 5, wherein the total protein content in the liquid milk-based infant formula milk is 1.0-2.5 g/100mL.
7. The method for preparing milk-based infant formula liquid milk according to claim 3, wherein the temperature of the purified water in step (3) and step (4) is 40-50°C.
8. The method for preparing milk-based infant formula liquid milk according to claim 3, wherein the homogenization condition is 20-30 MPa.
9. The method for preparing milk-based infant formula liquid milk according to claim 3, wherein the number of homogenization is 1 to 2 times.
10. The method for preparing milk-based infant formula liquid milk according to claim 3, wherein after sterilization, aseptic filling, cold chain transportation or low temperature refrigeration.
11. The method for preparing milk-based infant formula liquid milk according to claim 1, wherein the active protein comprises lactoferrin, immunoglobulin IgG, IgA, IgM, lactoperoxidase, complement protein C3, ribose Nuclease, lipocalin-2, lactectin or a combination thereof.
12. The method for preparing milk-based infant formula liquid milk according to claim 1, wherein the nutrients include whey protein powder, vegetable oil, lactose and phospholipids.
13. The method for preparing milk-based infant formula liquid milk according to claim 12, wherein the nutrients further include DHA, ARA, compound minerals and compound vitamins.
14. Infant formula milk prepared by the method for preparing milk-based infant formula liquid milk according to any one of claims 1-13.
15. Application of the method for preparing milk-based infant formula liquid milk according to any one of claims 1-13 in the food field.