Total nutrient milk capable of improving stability of vitamins and preparation method of total nutrient milk

Abstract

The invention provides total nutrient milk capable of improving the stability of vitamins and a preparation method of the total nutrient milk. The total nutrient milk is prepared from the following raw materials: an inner water phase component, an oil phase component, a polysaccharide component, a protein component and lactoferrin, the inner water phase component comprises a thickening agent, water-soluble vitamins, first carbohydrates and a buffer solution; the oil phase component comprises grease, medium chain triglyceride, polyglycerol ricinoleate, soybean lecithin and fat-soluble vitamins; the polysaccharide component comprises polysaccharide and water; the protein component comprises protein and water. The full-nutrition milk is prepared into a W / O / W type emulsion system by coordinating the interaction among the components in the system through a specific process, the system is of a two-membrane three-phase structure, vitamins can be distributed in different phases according to the physicochemical properties of various vitamins, and the three-phase environment can be adjusted respectively, so that the stability of the corresponding vitamins and the stability of the system are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of food, and particularly relates to a complete nutrition milk for improving the stability of vitamins and a preparation method thereof. Background Art

[0002] Foods for special medical purposes (hereinafter referred to as FSMP) refer to a type of formulated food specifically processed and prepared to meet the special nutritional needs of people with metabolic disorders, eating restrictions, digestive and absorption disorders, or specific disease states. FSMP can effectively improve the nutritional status of patients, thereby enhancing the patients' immunity, reducing the occurrence of complications, and shortening the hospital stay.

[0003] FSMP are mainly divided into two types: powder and emulsion. Compared with powder products, emulsion products are more convenient to use and have a wider range of clinical applications. However, to meet the nutritional needs of patients, FSMP complete nutrition milk contains many nutritional components, including carbohydrates, proteins, fats, 13 vitamins, 12 minerals and other nutritional components, and the system structure is complex. In the prior art, after the product is sterilized, the FSMP complete nutrition milk often faces the problems of poor system stability and poor nutrient stability. In past studies, after the product was sterilized, the vitamins with the highest loss rates were vitamin B1 (process loss rate 50-60%), vitamin C (process loss rate 30-40%), vitamin A (process loss rate 20-30%) in descending order, and other vitamins also had varying degrees of loss.

[0004] Therefore, how to improve the stability of vitamins in the system is crucial for ensuring the nutritional adequacy of FSMP complete nutrition milk.

[0005] The W / O / W emulsion is an emulsion system with a two-membrane three-phase structure, composed of an inner aqueous phase, an oil phase, and an outer aqueous phase. Its special structure has significant advantages in encapsulating active ingredients to protect them from the external environment. However, due to its complex structure, the aggregation of oil droplets, the polymerization of the inner aqueous phase, and the migration between the inner and outer aqueous phases will all lead to the instability of the W / O / W emulsion system, which limits its application in the food field. FSMP complete nutrition milk contains many nutritional components and the system is more complex. If we want to improve the vitamin stability by making FSMP complete nutrition milk into a W / O / W emulsion system, we need to solve the stability problems of the inner and outer oil-water interfaces.

[0006] In view of this, the present invention is specifically proposed. Summary of the Invention

[0007] One of the purposes of the present invention is to provide a complete nutrition milk for improving the stability of vitamins. The complete nutrition milk effectively improves the stability of vitamins and reduces the loss of vitamins.

[0008] The second object of the present invention is to provide a preparation method of a whole-nutrition milk for improving the stability of vitamins. The preparation method can well solve the problem that vitamins in the milk-based special medical whole-nutrition milk are easily lost during the process and shelf life. Without affecting the stability of the emulsion system, the loss of vitamins is reduced.

[0009] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0010] In the first aspect, the present invention provides a whole-nutrition milk for improving the stability of vitamins. The preparation raw materials of the whole-nutrition milk include an inner aqueous phase component, an oil phase component, a polysaccharide component, a protein component and lactoferrin.

[0011] The inner aqueous phase component includes a thickener, water-soluble vitamins, a first carbohydrate and a buffer solution.

[0012] The oil phase component includes oil, medium-chain triglycerides, polyglycerol ricinoleate, soybean phospholipids and fat-soluble vitamins.

[0013] The polysaccharide component includes polysaccharides and water.

[0014] The protein component includes proteins and water.

[0015] Preferably, in the inner aqueous phase component, the mass ratio of the thickener, water-soluble vitamins, the first carbohydrate and the buffer solution is (0.01-1):(0.7-12):(0.5-8):100;

[0016] Among them, "0.01-1" can be, for example, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.;

[0017] Among them, "0.7-12" can be, for example, 0.7, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.;

[0018] Among them, "0.5-8" can be, for example, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, etc.

[0019] Preferably, the thickener is an acid-resistant polysaccharide.

[0020] Preferably, the acid-resistant polysaccharide is selected from any one or a combination of at least two of gellan gum, pectin or xanthan gum.

[0021] Preferably, the water-soluble vitamins are selected from any one or a combination of at least two of ascorbic acid, thiamine, riboflavin or nicotinamide.

[0022] Preferably, the first carbohydrate is selected from any one or a combination of at least two of maltodextrin, corn starch, fructooligosaccharide or glucose.

[0023] Preferably, the pH of the buffer solution is 2.5 to 4.0, and for example, it can be 2.5, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, etc.

[0024] Preferably, the buffer solution is selected from any one or a combination of at least two of sodium citrate-citric acid buffer solution, disodium hydrogen phosphate-citric acid buffer solution or disodium hydrogen phosphate-phosphate buffer solution, and preferably sodium citrate-citric acid buffer solution.

[0025] Preferably, in the oil phase component, the mass ratio of the oil, medium-chain triglyceride, polyglyceryl ricinoleate, soybean phospholipid and fat-soluble vitamin is (80 - 20):(20 - 80):(1 - 4):(1 - 8):(0.05 - 0.5);

[0026] Among them, "80 - 20" can be, for example, 80, 70, 60, 50, 40, 30, 20, etc.;

[0027] Among them, "20 - 80" can be, for example, 20, 30, 40, 50, 60, 70, 80, etc.;

[0028] Among them, "1 - 4" can be, for example, 1, 1.5, 2, 2.5, 3, 3.5, 4, etc.;

[0029] Among them, "1 - 8" can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, etc.;

[0030] Among them, "0.05 - 0.5" can be, for example, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0031] Preferably, the oil is selected from any one or a combination of at least two of soybean oil, rapeseed oil, corn oil, sunflower oil, olive oil or fish oil.

[0032] Preferably, the fat-soluble vitamin is selected from any one or a combination of at least two of retinyl esters, cholecalciferol, tocopherols or phylloquinone.

[0033] Preferably, the mass ratio of the inner aqueous phase component to the oil phase component is 1:(3 - 5), and for example, it can be 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4, 1:4.2, 1:4.4, 1:4.6, 1:4.8, 1:5, etc.

[0034] Preferably, in the polysaccharide component, the mass ratio of the polysaccharide to water is (0.05 - 2.5):100, for example, it can be 0.05:100, 0.1:100, 0.2:100, 0.4:100, 0.6:100, 0.8:100, 1:100, 1.2:100, 1.4:100, 1.6:100, 1.8:100, 2:100, 2.2:100, 2.5:100, etc.

[0035] Preferably, the polysaccharide is selected from any one or a combination of at least two of carrageenan, xanthan gum, sodium alginate, sodium carboxymethyl cellulose, or chitosan.

[0036] Preferably, in the protein component, the mass ratio of the protein to water is (3 - 15):100, for example, it can be 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, 11:100, 12:100, 13:100, 14:100, 15:100, etc.

[0037] Preferably, the protein is selected from any one or a combination of at least two of caseinate, casein, whey protein, or soy protein isolate, etc.

[0038] Preferably, the mass ratio of the polysaccharide component to the protein component is 1:(3 - 3.5), for example, it can be 1:3, 1:3.1, 1:3.2, 1:3.3, 1:3.4, 1:3.5, etc.

[0039] Preferably, the addition amount of lactoferrin is 1 - 8% of the total mass of the polysaccharide component and the protein component, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc.

[0040] Preferably, the whole - nutrient milk further includes minerals.

[0041] Preferably, the minerals account for 0.05 - 5% of the total mass of the whole - nutrient milk, for example, it can be 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0042] Preferably, the minerals are selected from any one or a combination of at least two of tricalcium phosphate, copper sulfate, ferrous sulfate, manganese sulfate, magnesium sulfate, magnesium chloride, potassium chloride, potassium dihydrogen phosphate, potassium citrate, dipotassium hydrogen phosphate, sodium chloride, sodium citrate, sodium dihydrogen phosphate, disodium hydrogen phosphate, zinc sulfate, potassium iodide, or sodium selenite.

[0043] Preferably, the whole - nutrient milk further includes a second carbohydrate.

[0044] Preferably, the second carbohydrate accounts for 10-25% of the total mass of the whole-nutrition milk, and can be, for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 25%, etc.

[0045] Preferably, the second carbohydrate is selected from any one or a combination of at least two of maltodextrin, resistant dextrin, fructooligosaccharide, inulin or soy polysaccharide.

[0046] Preferably, the whole-nutrition milk further comprises a third vitamin.

[0047] Preferably, the third vitamin accounts for 0.0001%-0.02% of the total mass of the whole-nutrition milk, and can be, for example, 0.0001%, 0.0005%, 0.001%, 0.005%, 0.01%, 0.012%, 0.015%, 0.02%, etc.

[0048] Preferably, the third vitamin is selected from any one or a combination of at least two of pantothenic acid, biotin, folic acid, cyanocobalamin or pyridoxine.

[0049] In a second aspect, the present invention provides a method for preparing the whole-nutrition milk for improving the stability of vitamins as described in the first aspect, and the preparation method comprises the following steps:

[0050] Mix a thickener, a water-soluble vitamin, a first carbohydrate and a buffer solution to obtain an inner aqueous phase solution A; mix an oil, medium-chain triglyceride, polyglycerol ricinoleate, soy phospholipid and a fat-soluble vitamin to obtain an oil phase solution B;

[0051] Mix the inner aqueous phase solution A and the oil phase solution B, and perform a first emulsification treatment to obtain a water-in-oil primary emulsion C;

[0052] Mix a polysaccharide and water to obtain a polysaccharide solution D; mix a protein and water to obtain a protein solution E; mix the polysaccharide solution D, the protein solution E and lactoferrin to obtain a protein-polysaccharide mixture F;

[0053] Mix the water-in-oil primary emulsion C and the protein-polysaccharide mixture F, and perform a second emulsification treatment to obtain an emulsion G.

[0054] Preferably, the inner aqueous phase solution A is specifically prepared by the following steps:

[0055] Stir and dissolve the thickener in the buffer solution; then add the water-soluble vitamin and the first carbohydrate, and stir and mix to obtain the inner aqueous phase solution A.

[0056] It should be noted that during the preparation of the inner aqueous phase solution A, the water-soluble vitamins dissolved are relatively stable in acidic solutions. Therefore, these vitamins are dissolved in an acidic buffer solution with a pH of 2.5 - 4.0 to prepare the inner aqueous phase of this system.

[0057] The role of the acidic buffer solution is that on the one hand, it can adjust the pH range of the inner aqueous phase, and on the other hand, it can cooperate with the first carbohydrate to adjust the osmotic pressure of the inner aqueous phase solution A to balance the osmotic pressure gradient between the inner aqueous phase and the outer aqueous phase, avoiding the expansion of the inner aqueous phase due to the osmotic pressure difference in the final system, which may lead to the rupture of the oil film wrapped around the outer part of the inner aqueous phase, and ultimately result in the leakage of the vitamins embedded in the inner aqueous phase and the instability of the emulsion system. Compared with the conventional use of inorganic salts as osmotic pressure regulators, the water-soluble carbohydrates such as maltodextrin, corn starch, fructooligosaccharide, and glucose selected in this system will not cause the instability and degradation of the vitamins in the inner aqueous phase. In addition, since an acid-resistant thickener is added to the inner aqueous phase solution, the viscosity of the inner aqueous phase solution can be appropriately increased, which plays a role in slowing down the migration of the inner aqueous phase droplets and further improving the stability of the system.

[0058] More specifically, the inner aqueous phase solution A is specifically prepared by the following steps:

[0059] The thickener is dissolved in the buffer solution at 50 - 80 °C (such as 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, etc.) with stirring at 400 - 1000 rpm (such as 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc.) for 10 - 50 min (such as 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, etc.); then the water-soluble vitamins and the first carbohydrate are added, and at 20 - 50 °C (such as 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, etc.), with stirring at 400 - 1000 rpm (such as 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc.) for 5 - 15 min (such as 5 min, 6 min, 8 min, 10 min, 12 min, 15 min, etc.), and then the inner aqueous phase solution A is prepared.

[0060] Preferably, in the inner aqueous phase solution A, the addition amount of the thickener is 0.01-1% w / w of the mass of the buffer solution, and can be, for example, 0.01% w / w, 0.05% w / w, 0.1% w / w, 0.2% w / w, 0.3% w / w, 0.4% w / w, 0.5% w / w, 0.6% w / w, 0.7% w / w, 0.8% w / w, 0.9% w / w, 1% w / w, etc.

[0061] Preferably, in the inner aqueous phase solution A, the addition amount of the water-soluble vitamin is 0.7-12% w / w of the mass of the buffer solution, and can be, for example, 0.7% w / w, 0.8% w / w, 0.9% w / w, 1% w / w, 2% w / w, 4% w / w, 6% w / w, 8% w / w, 10% w / w, 12% w / w, etc.

[0062] Preferably, in the inner aqueous phase solution A, the addition amount of the first carbohydrate is 0.5-8% w / w of the mass of the buffer solution, and can be, for example, 0.5% w / w, 0.6% w / w, 0.7% w / w, 0.8% w / w, 0.9% w / w, 1% w / w, 2% w / w, 4% w / w, 6% w / w, 8% w / w, etc.

[0063] Preferably, the oil phase solution B is specifically prepared by the following steps:

[0064] First, mix the oil and medium-chain triglycerides to obtain a mixed oil; then add polyglyceryl ricinoleate and soy lecithin to the mixed oil and stir; then cool, and then add fat-soluble vitamins and stir to obtain the oil phase solution B.

[0065] It should be noted that during the preparation process of the oil phase solution B, the dissolved vitamins are all fat-soluble vitamins. The type of oil has a significant impact on the viscosity of the oil phase, the interfacial properties of the emulsion droplets, and the solubility of the encapsulated substances. Compared with other vegetable oils, medium-chain triglycerides have a smaller viscosity and interfacial tension, can reduce the deformation time of oil droplets during homogenization, improve the efficiency and effectiveness of emulsion droplet breakup, thereby reducing the emulsion particle size and improving the stability of the emulsion system.

[0066] In addition, medium-chain triglycerides per unit mass contain more polar groups, which can increase the solubility of related fat-soluble vitamins by promoting the formation of dipole-dipole interactions between molecules. Medium-chain triglycerides are also one of the sources of dietary fat, which can quickly supply energy to the human body and regulate the metabolism of nutrients such as sugars, fats, and proteins. However, they do not contain essential fatty acids for the human body, so they need to be compounded with other oils. Within the compounding ratio range of other oils and medium-chain triglycerides proposed in the present invention, designing the product oil formula according to the nutritional requirements of the target population can not only ensure the nutritional adequacy and safety of the target population, but also further improve the stability of the product system by appropriately increasing the proportion of MCT in the oil phase.

[0067] Polyglycerol ricinoleate is the most widely used lipophilic emulsifier in food emulsions. However, it belongs to a synthetic surfactant, and when its dosage in food exceeds 5%, it will affect the food sensory properties and does not conform to the current people's concept of green and healthy consumption. The present invention compounds polyglycerol ricinoleate and the natural emulsifier soy lecithin, and cooperates with proteins and polysaccharides in the subsequent external aqueous phase solution, which can not only prepare a stable multiple emulsion system, but also significantly reduce the dosage of polyglycerol ricinoleate.

[0068] Preferably, in the oil phase solution B, the mass ratio of the oil and medium-chain triglycerides is 4:1 to 1:4, such as 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, etc.

[0069] Preferably, in the oil phase solution B, the addition amount of polyglycerol ricinoleate is 1-4% w / w of the mass of the mixed oils, such as 1% w / w, 1.5% w / w, 2% w / w, 2.5% w / w, 3% w / w, 3.5% w / w, 4% w / w, etc.

[0070] Preferably, in the oil phase solution B, the addition amount of soy lecithin is 1-8% w / w of the mass of the mixed oils, such as 1% w / w, 1.5% w / w, 2% w / w, 2.5% w / w, 3% w / w, 3.5% w / w, 4% w / w, 5% w / w, 5.5% w / w, 6% w / w, 6.5% w / w, 7% w / w, 7.5% w / w, 8% w / w, etc.

[0071] Preferably, in the oil phase solution B, the addition amount of fat-soluble vitamins is 0.05-0.5% w / w of the mass of the mixed oils, such as 0.05% w / w, 0.06% w / w, 0.08% w / w, 0.1% w / w, 0.15% w / w, 0.2% w / w, 0.25% w / w, 0.3% w / w, 0.35% w / w, 0.4% w / w, 0.45% w / w, 0.5% w / w, etc.

[0072] More specifically, the oil phase solution B is prepared by the following steps:

[0073] First, mix the oil and medium-chain triglycerides to obtain a mixed oil; then add polyglyceryl ricinoleate and soybean phospholipids to the mixed oil, and stir at 50-70 °C (such as 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, etc.) at 400-1000 rpm (such as 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc.) for 10-40 min (such as 10 min, 20 min, 25 min, 30 min, 35 min, 40 min, etc.); then cool to 20-50 °C (such as 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, etc.), and then add fat-soluble vitamins, and stir at 400-1000 rpm (such as 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc.) for 5-30 min (such as 5 min, 6 min, 8 min, 10 min, 12 min, 15 min, 20 min, 25 min, 30 min, etc.) to obtain the oil phase solution B.

[0074] Preferably, the water-in-oil primary emulsion C is prepared by the following steps:

[0075] Add the inner aqueous phase solution A to the oil phase solution B, first perform shear treatment, and then perform homogenization treatment to obtain the water-in-oil primary emulsion C.

[0076] It should be noted that the primary emulsion C is a water-in-oil emulsion (W / O). This step uses the oil phase liquid B to encapsulate the inner aqueous phase solution A, which can not only place vitamins such as ascorbic acid, thiamine, riboflavin, and niacinamide in an acidic independent space conducive to their stability, but also inhibit the oxidation and destruction of vitamins in the inner aqueous phase solution A by pro-oxidant components such as iron and copper in the outer aqueous phase solution.

[0077] More specifically, the water-in-oil primary emulsion C is prepared by the following steps:

[0078] Add the inner aqueous phase solution A to the oil phase solution B, first shear at a speed of 8000 - 14000 rpm (such as 8000 rpm, 9000 rpm, 10000 rpm, 11000 rpm, 12000 rpm, 13000 rpm, 14000 rpm, etc.) for 10 - 20 min (such as 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, etc.); then homogenize at a pressure of 50 - 80 MPa (such as 50 MPa, 55 MPa, 60 MPa, 65 MPa, 70 MPa, 75 MPa, 80 MPa, etc.) for 2 - 4 times (such as 2 times, 3 times, 4 times) to obtain the water-in-oil type primary emulsion C.

[0079] Preferably, the mass ratio of the inner aqueous phase solution A to the oil phase solution B is 1:(3 - 5), such as 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8, 1:4, 1:4.2, 1:4.4, 1:4.6, 1:4.8, 1:5, etc.

[0080] Preferably, the polysaccharide solution D is specifically prepared by the following steps:

[0081] Add the polysaccharide to water, perform shear treatment to dissolve it in water, and fully hydrate the polysaccharide to obtain the polysaccharide solution D.

[0082] More specifically, the polysaccharide solution D is specifically prepared by the following steps:

[0083] Add the polysaccharide to water, shear at 7000 - 10000 rpm (such as 7000 rpm, 8000 rpm, 9000 rpm, 10000 rpm, etc.) at 50 - 70 °C (such as 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, etc.) for 10 - 60 min (such as 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc.) to dissolve it in water, and obtain the polysaccharide solution D.

[0084] Preferably, in the polysaccharide solution D, the addition amount of the polysaccharide is 0.05 - 2.5% w / w of the mass of water, such as 0.05% w / w, 0.075% w / w, 1% w / w, 1.2% w / w, 1.4% w / w, 1.6% w / w, 1.8% w / w, 2% w / w, 2.2% w / w, 2.5% w / w, etc.

[0085] Preferably, the protein solution E is specifically prepared by the following steps:

[0086] Add the protein to water, first perform shearing treatment to dissolve it in water; then perform heat treatment to obtain protein solution E.

[0087] It should be noted that in the present invention, precise heat treatment is performed on the protein. Under the following heat treatment conditions, the protein molecules can unfold more fully and expose hydrophobic groups. Due to the enhanced hydrophobic interaction between protein molecules, they aggregate with each other to form flocculent aggregates.

[0088] More specifically, the protein solution E is specifically prepared by the following steps:

[0089] Add the protein to water, shear at 40 - 50 °C (such as 40 °C, 42 °C, 44 °C, 46 °C, 48 °C, 50 °C, etc.) at 4000 - 8000 rpm (such as 4000 rpm, 5000 rpm, 6000 rpm, 7000 rpm, 8000 rpm, etc.) for 5 - 20 min (such as 5 min, 6 min, 8 min, 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, etc.) to dissolve it in water; then perform heat treatment at 60 - 70 °C (such as 60 °C, 62 °C, 64 °C, 66 °C, 68 °C, 70 °C, etc.) at 500 - 1500 rpm (such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1200 rpm, 1400 rpm, 1500 rpm, etc.) for 10 - 30 min (such as 10 min, 15 min, 20 min, 25 min, 30 min, etc.) to obtain protein solution E.

[0090] Preferably, in the protein solution E, the addition amount of the protein is 3 - 15% w / w of the mass of water, such as 3% w / w, 4% w / w, 6% w / w, 8% w / w, 10% w / w, 12% w / w, 13% w / w, 14% w / w, 15% w / w, etc.

[0091] Preferably, the protein - polysaccharide mixture F is specifically prepared by the following steps:

[0092] Under the state of heating and stirring, add the polysaccharide solution D to the protein solution E and stir; then add lactoferrin and continue to stir to obtain the protein - polysaccharide mixture F.

[0093] First, it should be noted that during the preparation of the protein-polysaccharide mixture F, as the polysaccharide solution is added and stirring continues, the flocculent aggregates formed by the protein gradually disappear. This is because heat treatment changes and stretches the internal peptide chain structure of the protein, exposing charged groups, and enhancing its ability to bind to macromolecular polysaccharides through electrostatic interactions. At the same time, the steric hindrance effect of the macromolecular polysaccharide hinders the aggregation between protein molecules, ultimately forming a soluble protein-polysaccharide complex.

[0094] Secondly, it should be noted that if the heat treatment conditions are too intense, the protein will form irreversible aggregates. In the present invention, the protein-polysaccharide complex can form strong electrostatic repulsion and steric hindrance between droplets, and can form a rigid film on the surface of the oil droplets, thereby slowing down the tendency of emulsion droplets to flocculate and merge, restricting the migration of water between the internal and external aqueous phases, and inhibiting or slowing down the release of the encapsulated substances in the internal aqueous phase and the oil phase. The interfacial barrier formed by the protein-polysaccharide complex can also reduce the contact between the vitamins in the internal aqueous phase and the oil phase and the pro-oxidant components in the external aqueous phase, thereby improving the stability of the vitamins.

[0095] Finally, it should be noted that during the preparation of the protein-polysaccharide mixture F, lactoferrin is added. The lactoferrin molecule can bind to metal ions such as 2+ Fe 3+ Ca 2+ Cu 2+ Zn 2+ Mn 2+ in the subsequent emulsion. After the lactoferrin binds to the metal ions in the system, it can not only inhibit the oxidative degradation of nutrients such as vitamins and unsaturated fatty acids in the system, but also improve the thermal stability of lactoferrin by enhancing the interaction between the glycan chain and amino acid molecules of the lactoferrin molecule through its binding to multivalent metal cations. In addition, lactoferrin is a glycoprotein containing hydrophilic carbohydrate groups that can extend into the surrounding aqueous phase, thereby forming a relatively thick hydrophilic layer. The glycosylated part of lactoferrin also provides a strong steric hindrance to prevent the aggregation of other proteins in the system induced by metal ions.

[0096] In addition, it is worth noting that the addition sequence of lactoferrin is extremely important. If lactoferrin is dissolved with other proteins in step E and heat-treated to form flocculent heat aggregates, and then polysaccharide solution D is added subsequently, the flocculent aggregates cannot disappear. This may be because the pH range of the final system of the present invention is between 6.5 and 7.5, and the isoelectric point of lactoferrin is pH 8.0 - 8.5. Within the pH range of the system, lactoferrin carries a positive charge, while the isoelectric points of other proteins in the system are lower than the pH range of the system, and the proteins carry a negative charge. The electrostatic interaction between lactoferrin and other proteins is much stronger than the interaction between polysaccharides and other protein molecules. Therefore, polysaccharides cannot form soluble complexes with denatured proteins.

[0097] More specifically, the protein-polysaccharide mixture F is specifically prepared by the following steps:

[0098] At 60 - 70 °C (such as 60 °C, 62 °C, 64 °C, 66 °C, 68 °C, 70 °C, etc.) and 500 - 1500 rpm (such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1200 rpm, 1400 rpm, 1500 rpm, etc.), add the polysaccharide solution D to the protein solution E and stir for 5 - 30 min (such as 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.); then add lactoferrin and continue to stir for 5 - 20 min (such as 5 min, 10 min, 15 min, 20 min, etc.) to obtain the protein-polysaccharide mixture F.

[0099] Preferably, the mass ratio of the polysaccharide solution D to the protein solution E is 1:(3 - 3.5), such as 1:3, 1:3.1, 1:3.2, 1:3.3, 1:3.4, 1:3.5, etc.

[0100] Preferably, in the protein-polysaccharide mixture F, the addition amount of lactoferrin is 1 - 8% w / w of the total mass of the mixture of the protein solution E and the polysaccharide solution D, such as 1% w / w, 2% w / w, 3% w / w, 4% w / w, 5% w / w, 6% w / w, 7% w / w, 8% w / w, etc.

[0101] Preferably, the emulsion G is specifically prepared by the following steps:

[0102] Add the water-in-oil primary emulsion C to the protein-polysaccharide mixture F and perform shear treatment; then perform homogenization treatment to obtain the emulsion G.

[0103] More specifically, the emulsion G is specifically prepared by the following steps:

[0104] At 3000 - 8000 rpm (such as 3000 rpm, 4000 rpm, 5000 rpm, 6000 rpm, 7000 rpm, 8000 rpm, etc.), the water-in-oil primary emulsion C is added to the protein-polysaccharide mixture F and sheared for 10 - 20 min (such as 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, etc.); then homogenized at a pressure of 20 - 40 MPa (such as 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, etc.) for 1 - 2 times (such as 1 time, 2 times) to obtain the emulsion G.

[0105] Preferably, the mass ratio of the water-in-oil primary emulsion C to the protein-polysaccharide mixture F is 1:(15 - 20), such as 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, etc.

[0106] As a preferred embodiment of the present invention, the preparation method of the whole-nutrition milk for improving vitamin stability further includes the following steps:

[0107] The emulsion G is mixed with minerals, the second carbohydrate, and the third vitamin to obtain the emulsion H;

[0108] The emulsion H is sterilized to obtain the whole-nutrition milk for improving vitamin stability.

[0109] Preferably, the emulsion H is specifically prepared by the following steps:

[0110] Under stirring, minerals are added to the emulsion G; then the second carbohydrate and the third vitamin are added, and stirring is continued to obtain the emulsion H.

[0111] It should be noted that during the preparation of the emulsion H, all the third vitamins dissolved in this step are vitamins that are relatively stable in a neutral environment, and these minerals and the second carbohydrate are added here instead of when preparing the protein-polysaccharide mixture F to form a complete outer aqueous phase, in order to avoid these substances interfering with the adsorption of various biological macromolecules in the protein-polysaccharide mixture F at the oil-water interface, thereby improving the stability of this composite system.

[0112] More specifically, the emulsion H is specifically prepared by the following steps:

[0113] At 40 - 50 °C (such as 40 °C, 42 °C, 44 °C, 46 °C, 48 °C, 50 °C, etc.) and 500 - 2000 rpm (such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, 2000 rpm, etc.), minerals are added to emulsion G and stirred for 15 - 30 min (such as 15 min, 20 min, 25 min, 30 min, etc.); then the second carbohydrate and the third vitamin are added and stirred for 2 - 10 min (such as 2 min, 4 min, 6 min, 8 min, 10 min, etc.) to obtain the said emulsion H.

[0114] Preferably, the pH of the said emulsion H is 6.5 - 7.5, such as 6.5, 6.6, 6.8, 7.0, 7.2, 7.4, 7.5, etc.

[0115] Preferably, in the said emulsion H, the addition amount of minerals is 0.5 - 5% w / w of the mass of emulsion G, such as 0.5% w / w, 1% w / w, 1.5% w / w, 2% w / w, 2.5% w / w, 3% w / w, 3.5% w / w, 4% w / w, 4.5% w / w, 5% w / w, etc.

[0116] Preferably, in the said emulsion H, the addition amount of the second carbohydrate is 10 - 25% w / w of the mass of emulsion G, such as 10% w / w, 12% w / w, 14% w / w, 16% w / w, 18% w / w, 20% w / w, 22% w / w, 24% w / w, 25% w / w, etc.

[0117] Preferably, in the said emulsion H, the addition amount of the third vitamin is 0.0001 - 0.02% w / w of the mass of emulsion G, such as 0.0001% w / w, 0.0005% w / w, 0.001% w / w, 0.005% w / w, 0.01% w / w, 0.02% w / w, etc.

[0118] Preferably, the sterilization temperature is 105 - 121 °C, such as 105 °C, 106 °C, 108 °C, 110 °C, 115 °C, 121 °C, etc., and the sterilization time is 8 - 15 min, such as 8 min, 10 min, 12 min, 14 min, 15 min, etc.

[0119] Compared with the prior art, the present invention has the following beneficial effects:

[0120] (1) The present invention makes the special medical total nutrition emulsion into a W / O / W emulsion system. According to the physical and chemical properties of vitamins, various vitamins in the system are distributed in the inner aqueous phase, oil phase, and outer aqueous phase, and the three-phase environment is adjusted respectively to make it conducive to the stability of the corresponding vitamins, and finally significantly reduce the loss of related vitamins;

[0121] (2) The present invention coordinates the interaction between the components in the system through a specific process, and finally makes a stable special medical total nutrition multiple emulsion; it meets the special medical regulations that the special medical total nutrition emulsion must contain carbohydrates, proteins, fats, 13 vitamins, and 12 minerals, and can also add optional components such as dietary fiber and amino acids according to the nutritional needs of the target population;

[0122] (3) Through the preparation method of the present invention, the protein content in the total nutrition milk can reach 7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0123] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0124] Figure 1 Fingerprint of the LUM stability analyzer for simulating the stratification of the emulsion in Example 1 during a 1-year shelf life.

[0125] Figure 2 Fingerprint of the LUM stability analyzer for simulating the stratification of the emulsion in Example 2 during a 1-year shelf life.

[0126] Figure 3 Fingerprint of the LUM stability analyzer for simulating the stratification of the emulsion in Comparative Example 1 during a 1-year shelf life.

[0127] Figure 4 Fingerprint of the LUM stability analyzer for simulating the stratification of the emulsion in Comparative Example 2 during a 1-year shelf life.

[0128] Figure 5 Fingerprint of the LUM stability analyzer for simulating the stratification of the emulsion in Comparative Example 3 during a 1-year shelf life. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0129] Unless otherwise defined herein, scientific and technical terms used in connection with the present invention shall have the meanings commonly understood by one of ordinary skill in the art. The meanings and scopes of the terms should be clear. However, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or extrinsic definition. In this application, unless otherwise specified, the use of "or" means "and / or". In addition, the use of the term "comprising" and other forms is non-restrictive.

[0130] It should be noted that specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0131] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0132] The present invention will be further described below through embodiments. Unless otherwise specified, the materials in the embodiments are prepared according to existing methods or directly purchased from the market.

[0133] Example 1

[0134] This example provides a whole-nutrition milk for improving the stability of vitamins. The whole-nutrition milk for improving the stability of vitamins is prepared by the following steps:

[0135] A. Preparation of internal aqueous solution A:

[0136] 0.3 g of pectin was added to 100 g of sodium citrate-citric acid buffer solution with a pH of 3.0, and stirred and dissolved at 60 °C and 600 rpm for 15 min. Then, 5.7 g of compound vitamin 1 (including ascorbic acid, thiamine, riboflavin, and nicotinamide in a mass ratio of 73.82:5.49:4.45:16.24) and 4 g of maltodextrin were added, and stirred and dissolved at 25 °C and 500 rpm for 10 min to obtain internal aqueous solution A;

[0137] B. Preparation of oil phase liquid B:

[0138] Mix 100 g of soybean oil, 100 g of olive oil, and 200 g of medium-chain triglycerides. Add 8 g of polyglyceryl ricinoleate and 10 g of soybean phospholipid to the mixed oil. Stir and dissolve at 60 °C and 600 rpm for 30 min. Then, at room temperature, add 0.35 g of compound vitamin 2 (including retinyl esters, cholecalciferol, tocopherols, and phylloquinone with a mass ratio of 10.39:0.08:84.02:5.51), and stir and dissolve for 10 min to obtain oil phase liquid B;

[0139] C. Preparation of primary emulsion C:

[0140] Add the inner aqueous phase solution A prepared in step A to the oil phase liquid B prepared in step B. Shear at a speed of 10000 rpm for 10 min, and then perform homogenization at a homogenization pressure of 70 MPa for 2 times to obtain primary emulsion C;

[0141] D. Preparation of polysaccharide solution D:

[0142] Add 1.5 g of carrageenan and 2.5 g of sodium carboxymethylcellulose to 2000 g of water. Shear and dissolve at 60 °C and 7000 rpm for 15 min to fully hydrate the polysaccharide and obtain polysaccharide solution D;

[0143] E. Preparation of protein solution E:

[0144] Add 400 g of casein to 6000 g of water. Shear and dissolve at 45 °C and 5000 rpm for 10 min. After the protein is dissolved, perform heat treatment at 65 °C and 800 rpm for 15 min to obtain protein solution E;

[0145] F. Preparation of protein-polysaccharide mixture F:

[0146] At 65 °C and 800 rpm, add the polysaccharide solution D prepared in step D to the protein solution E prepared in step E, stir for 15 min, add 150 g of lactoferrin, and continue to stir for 15 min to obtain protein-polysaccharide mixture F;

[0147] G. Preparation of emulsion G:

[0148] Under the condition of a rotation speed of 5000 rpm, slowly add the primary emulsion C prepared in step C to the protein-polysaccharide mixture F prepared in step F, shear for 10 min, and then perform homogenization 2 times under a homogenization pressure of 30 MPa to prepare emulsion G;

[0149] H. Preparation of emulsion H:

[0150] Under the conditions of 40 °C and 1500 rpm, 100 g of composite minerals (including potassium chloride, sodium citrate, potassium dihydrogen phosphate, tricalcium phosphate, magnesium oxide, sodium chloride, ferrous sulfate, zinc sulfate, copper sulfate, manganese sulfate, potassium iodide, and sodium selenite with a mass ratio of 30.34:20.80:16.10:12.28:10.84:8.26:0.62:0.4:0.15:0.15:0.03:0.03) were added to the emulsion G prepared in step G, and stirred for 20 min. Subsequently, 1400 g of maltodextrin and 0.16 g of composite vitamin 3 (including pantothenic acid, pyridoxine, folic acid, biotin, and cyanocobalamin with a mass ratio of 52.32:45.23:2.1:0.25:0.1) were added and stirred to dissolve for 5 min to prepare emulsion H;

[0151] I. Post-treatment:

[0152] The emulsion H prepared in step H was filled and sterilized at a sterilization temperature of 121 °C for 10 min to finally obtain the shown special medical food in emulsion form.

[0153] Example 2

[0154] This example provides a whole-nutrition milk for improving vitamin stability, and the whole-nutrition milk for improving vitamin stability is prepared by the following steps:

[0155] A. Preparation of the inner aqueous phase solution A:

[0156] Dissolve 0.3 g of pectin in 100 g of sodium citrate-citric acid buffer solution with a pH of 3.0, and stir to dissolve at 60 °C and 600 rpm for 15 min. Then add 5.7 g of composite vitamin 1 (including ascorbic acid, thiamine, riboflavin, and nicotinamide with a mass ratio of 73.82:5.49:4.45:16.24), 4 g of maltodextrin, and stir to dissolve at 25 °C and 500 rpm for 10 min to obtain the inner aqueous phase solution A;

[0157] B. Preparation of the oil phase liquid B:

[0158] Mix 100 g of soybean oil, 100 g of olive oil, and 200 g of medium-chain triglycerides. Add 8 g of polyglycerol ricinoleate and 10 g of soybean phospholipid to the mixed oils, and stir to dissolve at 60 °C and 600 rpm for 30 min. Subsequently, at room temperature, add 0.35 g of composite vitamin 2 (including retinyl ester, cholecalciferol, tocopherol, and phylloquinone with a mass ratio of 10.39:0.08:84.02:5.51), and stir to dissolve for 10 min to obtain the oil phase liquid B;

[0159] C. Preparation of the primary emulsion C:

[0160] Add the inner aqueous phase solution A prepared in step A to the oil phase liquid B prepared in step B, shear at a speed of 10,000 rpm for 10 min, then perform homogenization. The homogenization pressure is 70 MPa, and homogenize 2 times to obtain the primary emulsion C;

[0161] D. Preparation of polysaccharide solution D:

[0162] Add 2.5 g of carrageenan and 2.5 g of sodium carboxymethylcellulose to 2000 g of water, shear and dissolve at 60 °C and 7000 rpm for 15 min to fully hydrate the polysaccharide and obtain the polysaccharide solution D;

[0163] E. Preparation of protein solution E:

[0164] Add 650 g of casein to 6000 g of water, shear and dissolve at 45 °C and 5000 rpm for 15 min. After the protein is dissolved, perform heat treatment at 60 °C and 800 rpm for 20 min to obtain the protein solution E;

[0165] F. Preparation of protein-polysaccharide mixture F:

[0166] At 60 °C and 800 rpm, add the polysaccharide solution D prepared in step D to the protein solution E prepared in step E, stir for 20 min, add 150 g of lactoferrin, and continue to stir for 15 min to obtain the protein-polysaccharide mixture F;

[0167] G. Preparation of emulsion G:

[0168] Under the condition of a rotation speed of 5000 rpm, slowly add the primary emulsion C prepared in step C to the protein-polysaccharide mixture F prepared in step F, shear for 12 min, and then homogenize 2 times under a homogenization pressure of 30 MPa to obtain the emulsion G;

[0169] H. Preparation of emulsion H:

[0170] At 40 °C and 1500 rpm, add 100 g of compound minerals (including potassium chloride, sodium citrate, potassium dihydrogen phosphate, tricalcium phosphate, magnesium oxide, sodium chloride, ferrous sulfate, zinc sulfate, copper sulfate, manganese sulfate, potassium iodide, sodium selenite with a mass ratio of 30.34:20.80:16.10:12.28:10.84:8.26:0.62:0.4:0.15:0.15:0.03:0.03) to the emulsion G prepared in step G, stir for 20 min, and then add 1400 g of maltodextrin and 0.16 g of compound vitamin 3 (including pantothenic acid, pyridoxine, folic acid, biotin, cyanocobalamin with a mass ratio of 52.32:45.23:2.1:0.25:0.1), stir and dissolve for 5 min to obtain the emulsion H;

[0171] I. Post-treatment:

[0172] The emulsion H prepared in step H is filled and sterilized at a sterilization temperature of 121 °C and a sterilization time of 10 min to finally obtain the shown special medical food in emulsion form.

[0173] Example 3

[0174] This example provides a whole-nutrition milk for improving vitamin stability, and the whole-nutrition milk for improving vitamin stability is prepared by the following steps:

[0175] A. Preparation of the inner aqueous phase solution A:

[0176] 0.3 g of pectin is added to 100 g of sodium citrate-citric acid buffer solution with a pH of 3.0, and stirred and dissolved at 60 °C and 600 rpm for 15 min. Then, 5.7 g of compound vitamin 1 (including ascorbic acid and thiamine with a mass ratio of 1:1) and 4 g of maltodextrin are added, and stirred and dissolved at 25 °C and 500 rpm for 10 min to obtain the inner aqueous phase solution A;

[0177] B. Preparation of the oil phase liquid B:

[0178] 100 g of soybean oil, 100 g of olive oil, and 200 g of medium-chain triglycerides are mixed. 8 g of polyglycerol ricinoleate and 10 g of soybean phospholipid are added to the mixed oils and fats, and stirred and dissolved at 60 °C and 600 rpm for 30 min. Then, at room temperature, 0.35 g of vitamin 2 (retinol) is added and stirred and dissolved for 10 min to obtain the oil phase liquid B;

[0179] C. Preparation of the primary emulsion C:

[0180] The inner aqueous phase solution A prepared in step A is added to the oil phase liquid B prepared in step B, sheared at a speed of 10000 rpm for 10 min, and then homogenized at a homogenization pressure of 70 MPa for 2 times to obtain the primary emulsion C;

[0181] D. Preparation of the polysaccharide solution D:

[0182] 1.5 g of carrageenan and 2.5 g of sodium carboxymethylcellulose are added to 2000 g of water, and sheared and dissolved at 60 °C and 7000 rpm for 15 min to fully hydrate the polysaccharide to obtain the polysaccharide solution D;

[0183] E. Preparation of the protein solution E:

[0184] Add 400 g of casein to 6000 g of water, shear and dissolve at 45 °C and 5000 rpm for 10 min. After the protein is dissolved, perform heat treatment at 65 °C and 800 rpm for 15 min to obtain protein solution E;

[0185] F. Preparation of protein-polysaccharide mixture F:

[0186] At 65 °C and 800 rpm, add polysaccharide solution D prepared in step D to protein solution E prepared in step E, stir for 15 min, add 150 g of lactoferrin, and continue to stir for 15 min to obtain protein-polysaccharide mixture F;

[0187] G. Preparation of emulsion G:

[0188] Under the condition of 5000 rpm, slowly add the primary emulsion C prepared in step C to the protein-polysaccharide mixture F prepared in step F, shear for 10 min, and then homogenize twice at a homogenization pressure of 30 MPa to obtain emulsion G;

[0189] H. Preparation of emulsion H:

[0190] At 40 °C and 1500 rpm, add 100 g of complex minerals (including potassium chloride, sodium citrate, potassium dihydrogen phosphate, tricalcium phosphate, magnesium oxide, sodium chloride, ferrous sulfate, zinc sulfate, copper sulfate, manganese sulfate, potassium iodide, sodium selenite with a mass ratio of 30.34:20.80:16.10:12.28:10.84:8.26:0.62:0.4:0.15:0.15:0.03:0.03) to the emulsion G prepared in step G, stir for 20 min, and then add 1400 g of maltodextrin and stir to dissolve for 5 min to obtain emulsion H;

[0191] I. Post-treatment:

[0192] Fill and sterilize the emulsion H prepared in step H. The sterilization temperature is 121 °C and the sterilization time is 10 min to finally obtain the indicated special medical food in emulsion form.

[0193] Comparative Example 1

[0194] This comparative example provides a nutritional milk, and the nutritional milk is prepared by the following steps:

[0195] A. Preparation of oil phase liquid:

[0196] Mix 100 g of soybean oil, 100 g of olive oil, and 200 g of medium-chain triglycerides, add 10 g of soybean phospholipid to the mixed oil, and stir and dissolve at 60 °C and 600 rpm for 30 min;

[0197] B. Preparation of aqueous phase solution:

[0198] At 50 °C and 5000 rpm, 2.5 g of carrageenan, 2.5 g of sodium carboxymethylcellulose, 400 g of casein, 150 g of lactoferrin, 1400 g of maltodextrin, 100 g of complex minerals, and 6.21 g of complex vitamins were successively added to 8100 g of water, and sheared and dissolved for 40 min;

[0199] C. Preparation of crude emulsion:

[0200] At 50 °C and 5000 rpm, the oil phase solution A prepared in step A was added to the aqueous phase solution prepared in step B, and sheared for 10 min to obtain a crude emulsion;

[0201] D. Post-treatment:

[0202] The primary emulsion prepared in step C was homogenized at a homogenization pressure of 50 MPa for 2 times, and then canned and sterilized at a sterilization temperature of 121 °C for 10 min to obtain the nutrient milk.

[0203] Comparative Example 2

[0204] This comparative example provides a nutrient milk, which is prepared by the following steps:

[0205] A. Preparation of internal aqueous phase solution A:

[0206] 0.3 g of pectin was added to 100 g of sodium citrate-citric acid buffer solution with a pH of 3.0, and stirred and dissolved at 60 °C and 600 rpm for 15 min. Then, 5.7 g of complex vitamin 1 (including ascorbic acid, thiamine, riboflavin, and nicotinamide with a mass ratio of 73.82:5.49:4.45:16.24) and 4 g of maltodextrin were added, and stirred and dissolved at 25 °C and 500 rpm for 10 min to obtain internal aqueous phase solution A;

[0207] B. Preparation of oil phase solution B:

[0208] 100 g of soybean oil, 100 g of olive oil, and 200 g of medium-chain triglycerides were mixed, 8 g of polyglycerol ricinoleate and 10 g of soybean phospholipid were added to the mixed oil, and stirred and dissolved at 60 °C and 600 rpm for 30 min. Then, at room temperature, 0.35 g of complex vitamin 2 (including retinyl ester, cholecalciferol, tocopherol, and phylloquinone with a mass ratio of 10.39:0.08:84.02:5.51) was added and stirred and dissolved for 10 min to obtain oil phase solution B;

[0209] C. Preparation of primary emulsion C:

[0210] Add the inner aqueous phase solution A prepared in step A to the oil phase solution B prepared in step B, shear at a speed of 10000 rpm for 10 min, then perform homogenization at a homogenization pressure of 70 MPa for 2 times to obtain the primary emulsion C;

[0211] D. Preparation of the protein-polysaccharide mixture D:

[0212] At 50 °C and 7000 rpm, add 2.5 g of carrageenan, 2.5 g of sodium carboxymethylcellulose, 400 g of casein, and 150 g of lactoferrin to 8000 g of water in sequence, shear and dissolve for 30 min to obtain the protein-polysaccharide mixture D;

[0213] E. Preparation of the emulsion E:

[0214] Under the condition of a rotation speed of 5000 rpm, slowly add the primary emulsion C prepared in step C to the protein-polysaccharide mixture D prepared in step D, shear for 10 min, and then homogenize 2 times under a homogenization pressure of 30 MPa to obtain the emulsion E;

[0215] F. Preparation of the emulsion F:

[0216] At 40 °C and 1500 rpm, add 100 g of the composite mineral to the emulsion E prepared in step E, stir for 20 min, then add 1400 g of maltodextrin and 0.16 g of the composite vitamin 3 (including pantothenic acid, pyridoxine, folic acid, biotin, and cyanocobalamin with a mass ratio of 52.32:45.23:2.1:0.25:0.1), and stir and dissolve for 5 min to obtain the emulsion F;

[0217] G. Post-treatment:

[0218] Fill and sterilize the emulsion F prepared in step F at a sterilization temperature of 121 °C for 10 min.

[0219] Comparative Example 3

[0220] This comparative example provides a nutritional milk, which is prepared by the following steps:

[0221] A. Preparation of the inner aqueous phase solution A:

[0222] Add 0.3 g of pectin to 100 g of sodium citrate-citric acid buffer solution with a pH of 3.0, stir and dissolve at 60 °C and 600 rpm for 15 min, then add 5.7 g of the composite vitamin 1 (including ascorbic acid, thiamine, riboflavin, and nicotinamide with a mass ratio of 73.82:5.49:4.45:16.24) and 4 g of maltodextrin, and stir and dissolve at 25 °C and 500 rpm for 10 min to obtain the inner aqueous phase solution A;

[0223] B. Preparation of oil phase liquid B:

[0224] Mix 100 g of soybean oil, 100 g of olive oil, and 200 g of medium-chain triglycerides. Add 8 g of polyglyceryl ricinoleate and 10 g of soybean phospholipid to the mixed oils and fats. Stir and dissolve at 60 °C and 600 rpm for 30 min. Then, at room temperature, add 0.35 g of compound vitamin 2 (including retinyl ester, cholecalciferol, tocopherol, and phylloquinone with a mass ratio of 10.39:0.08:84.02:5.51), and stir and dissolve for 10 min to obtain oil phase liquid B;

[0225] C. Preparation of primary emulsion C:

[0226] Add the inner aqueous phase solution A prepared in step A to the oil phase liquid B prepared in step B. Shear at 10000 rpm for 10 min, and then perform homogenization. The homogenization pressure is 70 MPa, and homogenize twice to obtain primary emulsion C;

[0227] D. Preparation of polysaccharide solution D:

[0228] Add 2.5 g of carrageenan and 2.5 g of sodium carboxymethylcellulose to 2000 g of water. Shear and dissolve at 60 °C and 7000 rpm for 15 min to fully hydrate the polysaccharide and obtain polysaccharide solution D;

[0229] E. Preparation of protein solution E:

[0230] Add 400 g of casein to 6000 g of water. Shear and dissolve at 45 °C and 5000 rpm for 15 min. After the protein is dissolved, perform heat treatment at 65 °C and 800 rpm for 15 min to obtain protein solution E;

[0231] F. Preparation of outer aqueous phase solution F:

[0232] At 65 °C and 800 rpm, add the polysaccharide solution D prepared in step D to the protein solution E prepared in step E, stir for 15 min, add 150 g of lactoferrin, continue to stir for 15 min, add 100 g of compound minerals, stir for 20 min, then add 1400 g of maltodextrin and 0.16 g of compound vitamin 3 (including pantothenic acid, pyridoxine, folic acid, biotin, and cyanocobalamin with a mass ratio of 52.32:45.23:2.1:0.25:0.1), and stir and dissolve for 5 min to obtain outer aqueous phase solution F

[0233] G. Preparation of emulsion G:

[0234] Under the condition of a rotational speed of 5000 rpm, the primary emulsion C prepared in step C was slowly added to the external aqueous phase solution F prepared in step F, sheared for 10 min, and then homogenized twice under a homogenization pressure of 30 MPa to obtain emulsion G;

[0235] H. Post-treatment:

[0236] The emulsion G prepared in step G was filled and sterilized at a sterilization temperature of 121 °C for 10 min.

[0237] Comparative Example 4

[0238] This comparative example provides a nutritional milk, which is different from Example 1 only in that the sodium citrate-citric acid buffer solution in the internal aqueous phase solution A is replaced with water of equal mass, and the contents of other components and the preparation method are exactly the same as those in Example 1.

[0239] Comparative Example 5

[0240] This comparative example provides a nutritional milk, which is different from Example 1 only in that medium-chain triglycerides are no longer added to the oil phase liquid B, the content of soybean oil is increased to 200 g, and the content of olive oil is increased to 200 g, and the contents of other components and the preparation method are exactly the same as those in Example 1.

[0241] Comparative Example 6

[0242] This comparative example provides a nutritional milk, which is different from Example 1 only in that lactoferrin is no longer added to the protein polysaccharide mixture F, and the contents of other components and the preparation method are exactly the same as those in Example 1.

[0243] Test Example 1

[0244] LUM Stability Analysis

[0245] Test samples: The whole-nutrition milk for improving vitamin stability provided in Examples 1-2, and the nutritional milk provided in Comparative Examples 1-3;

[0246] Test method: Use a LUM stability analyzer to detect the stability of the above samples simulating a 1-year shelf life;

[0247] Test results: As Figures 1 to 5 shown.

[0248] Among them, the LUM stability analyzer was used to simulate the stability of the sample in Example 1 for 1 year, as Figure 1 shown. Although most of the particles in the sample system of Example 1 floated, there was also a small amount of sedimentation, but the curve changed relatively gently, the sample was relatively stable as a whole, and after slight shaking, the sample could return to a homogeneous system state.

[0249] Among them, the LUM stability analyzer was used to simulate the stability of the sample in Example 2 during the 1-year shelf life, as Figure 2 shown. The protein content of Example 2 is higher than that of Example 1, which to a certain extent leads to lower stability of the system than that of Example 1. The sedimentation phenomenon of the sample in Example 2 is more obvious than that in Example 1. This may be because the protein content of the sample in Example 2 is relatively high, and after the product is sterilized at high temperature, the protein undergoes slight thermal aggregation. However, the stability of the sample in Example 2 is still within the acceptable range. After slight shaking, the sample can return to a homogeneous system state.

[0250] Among them, the LUM stability analyzer was used to simulate the stability of the sample in Comparative Example 1 during the 1-year shelf life, as Figure 3 shown. The sample in Comparative Example 1 is a full-nutrition milk prepared by a conventional method. It can be seen from the fingerprint that the sample in Comparative Example 1 also showed floating and sedimentation phenomena during the 1-year shelf life. The system stabilities of Example 1 and Example 2 are inferior to that of Comparative Example 1 to a certain extent. This is inevitable for the W / O / W type emulsion system compared with the O / W type simple emulsion system. However, after making an acceptable concession in terms of system stability, Example 1 and Example 2 effectively improve the stability of vitamins, which is particularly important for ensuring the nutritional adequacy of special medical foods.

[0251] Among them, the LUM stability analyzer was used to simulate the stability of the sample in Comparative Example 2 during the 1-year shelf life, as Figure 4 shown. Compared with Example 1, in the preparation process of the protein-polysaccharide mixture in Comparative Example 2, the protein and polysaccharide were simply dissolved and mixed. From Figure 4 the fingerprint, it can be seen that the sample in Comparative Example 2 showed serious floating phenomenon during the 1-year shelf life, and the curve changed in a wavy shape, indicating that different sedimentation layers appeared in the system, and the sample system was extremely unstable. This shows that the preparation step of the protein-polysaccharide mixture in the present invention plays an important role in maintaining the stability of the emulsion system.

[0252] Among them, the LUM stability analyzer was used to simulate the stability of the sample in Comparative Example 3 during the 1-year shelf life, as Figure 5 shown. Compared with Example 1, in Comparative Example 3, the complex minerals, carbohydrate 2, and complex vitamin 3 were added during the preparation of the protein-polysaccharide mixed solution to directly prepare a complete outer aqueous phase solution in one step. From Figure 5 the fingerprint, it can be seen that the sample in Comparative Example 3 showed serious floating phenomenon during the 1-year shelf life, and the curve changed in a wavy shape, indicating that different sedimentation layers appeared in the system, and the sample system was extremely unstable. This shows that after the protein-polysaccharide mixture F is mixed and homogenized with the primary emulsion C, and then the complex minerals, carbohydrate 2, and complex vitamin 3 are added, the stability of the complex emulsion can be effectively improved.

[0253] Test Example 2

[0254] Process loss rate of vitamins

[0255] Test samples: The full-nutrition milk that improves the stability of vitamins provided in Examples 1 to 3, and the nutrition milk provided in Comparative Examples 1 to 6;

[0256] Test method:

[0257] Detect the contents of three vitamins with the most serious loss in previous studies, namely vitamin B1 (detection method: GB 5009.84-2016 "National Food Safety Standard Determination of Vitamin B1 in Foods" (the first method)), vitamin C (detection method: GB 5413.18-2010 "National Food Safety Standard Determination of Vitamin C in Foods"), vitamin A (detection method: GB5009.82-2016 "National Food Safety Standard Determination of Vitamins A, D, and E in Foods" (the first method)), and calculate the process loss rate. The test results are shown in Table 1 below.

[0258] Table 1

[0259]

[0260] It can be seen from Table 1 that the process loss rate of vitamin B1 in the full-nutrition milk sample prepared by the method of the present invention is below 42%, the process loss rate of vitamin C is below 17%, and the process loss rate of vitamin A is below 14%. It shows that the preparation method of the present invention solves the problem of large vitamin loss in the traditional preparation method and overcomes the problem of poor stability of the W / O / W emulsion system in a complex system.

[0261] In summary, the full-nutrition milk of the present invention contains nutritional components such as carbohydrates, proteins, fats, 13 vitamins, and 12 minerals. Through a specific process to coordinate the interaction between components in the system, the full-nutrition milk is prepared into a W / O / W emulsion system, which is a "two-film three-phase" structure. According to the physical and chemical properties of 13 vitamins, the vitamins are distributed in different phases, and the three-phase environment is adjusted respectively to make it beneficial to the stability of the corresponding vitamins and the stability of the system. The preparation method of the special medical full-nutrition milk provided by the present invention solves the problem of large vitamin loss in the traditional preparation method, overcomes the problem of poor stability of the W / O / W emulsion system in a complex system, and effectively improves the protein content in the full-nutrition emulsion system to a certain extent.

[0262] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A full-nutrition milk for improving vitamin stability, characterized in that, The raw materials for preparing the total-nutrition milk include an inner aqueous phase component, an oil phase component, a polysaccharide component, a protein component, and lactoferrin; The inner aqueous phase component includes a thickener, water-soluble vitamins, a first carbohydrate, and a buffer solution; The oil phase component includes oils and fats, medium-chain triglycerides, polyglyceryl ricinoleate, soybean phospholipids, and fat-soluble vitamins; The polysaccharide component includes polysaccharides and water; The protein component includes proteins and water.

2. The full-nutrition milk for improving vitamin stability according to claim 1, characterized in that In the inner aqueous phase component, the mass ratio of the thickener, water-soluble vitamins, the first carbohydrate, and the buffer solution is (0.01 - 1):(0.7 - 12):(0.5 - 8):100; Preferably, the thickener is an acid-resistant polysaccharide; Preferably, the acid-resistant polysaccharide is selected from any one or a combination of at least two of gellan gum, pectin, or xanthan gum; Preferably, the water-soluble vitamins are selected from any one or a combination of at least two of ascorbic acid, thiamine, riboflavin, or niacinamide; Preferably, the first carbohydrate is selected from any one or a combination of at least two of maltodextrin, corn starch, fructooligosaccharide, or glucose; Preferably, the pH of the buffer solution is 2.5 - 4.0; Preferably, the buffer solution is selected from any one or a combination of at least two of sodium citrate - citric acid buffer solution, disodium hydrogen phosphate - citric acid buffer solution, or disodium hydrogen phosphate - phosphate buffer solution, and preferably is sodium citrate - citric acid buffer solution.

3. The full-nutrition milk for improving the stability of vitamins according to claim 1 or 2, characterized in that, In the oil phase component, the mass ratio of the oils and fats, medium-chain triglycerides, polyglyceryl ricinoleate, soybean phospholipids, and fat-soluble vitamins is (80 - 20):(20 - 80):(1 - 4):(1 - 8):(0.05 - 0.5); Preferably, the oils and fats are selected from any one or a combination of at least two of soybean oil, rapeseed oil, corn oil, sunflower oil, olive oil, or fish oil; Preferably, the fat-soluble vitamins are selected from any one or a combination of at least two of retinyl esters, cholecalciferol, tocopherols, or phylloquinone; Preferably, the mass ratio of the inner aqueous phase component to the oil phase component is 1:(3 - 5).

4. The full-nutrition milk for improving vitamin stability according to claim 1, characterized in that, In the polysaccharide component, the mass ratio of the polysaccharides to water is (0.05 - 2.5):100; Preferably, the polysaccharides are selected from any one or a combination of at least two of carrageenan, xanthan gum, sodium alginate, sodium carboxymethyl cellulose, or chitosan; Preferably, in the protein component, the mass ratio of the proteins to water is (3 - 15):100; Preferably, the proteins are selected from any one or a combination of at least two of caseinates, casein, whey protein, or soy protein isolate; Preferably, the mass ratio of the polysaccharide component to the protein component is 1:(3 - 3.5); Preferably, the addition amount of lactoferrin is 1 - 8% of the total mass of the polysaccharide component and the protein component.

5. The full-nutrition milk for improving vitamin stability according to claim 1, characterized in that, The total-nutrition milk also includes minerals; Preferably, the minerals account for 0.05 - 5% of the total mass of the total-nutrition milk; Preferably, the mineral is selected from any one or a combination of at least two of tricalcium phosphate, copper sulfate, ferrous sulfate, manganese sulfate, magnesium sulfate, magnesium chloride, potassium chloride, potassium dihydrogen phosphate, potassium citrate, dipotassium hydrogen phosphate, sodium chloride, sodium citrate, sodium dihydrogen phosphate, disodium hydrogen phosphate, zinc sulfate, potassium iodide or sodium selenite; Preferably, the total nutrient milk further comprises a second carbohydrate; Preferably, the second carbohydrate accounts for 10-25% of the total mass of the total nutrient milk; Preferably, the second carbohydrate is selected from any one or a combination of at least two of maltodextrin, resistant dextrin, fructooligosaccharide, inulin or soy polysaccharide; Preferably, the total nutrient milk further comprises a third vitamin; Preferably, the third vitamin accounts for 0.0001%-0.02% of the total mass of the total nutrient milk; Preferably, the third vitamin is selected from any one or a combination of at least two of pantothenic acid, biotin, folic acid, cyanocobalamin or pyridoxine.

6. A method for preparing a full-nutrition milk for improving vitamin stability according to any one of claims 1 to 5, characterized in that, The preparation method comprises the following steps: Mix a thickener, water-soluble vitamins, a first carbohydrate and a buffer solution to obtain an inner aqueous phase solution A; mix oils and fats, medium-chain triglycerides, polyglyceryl ricinoleate, soy lecithin and fat-soluble vitamins to obtain an oil phase solution B; Mix the inner aqueous phase solution A and the oil phase solution B and perform a first emulsification treatment to obtain a water-in-oil primary emulsion C; Mix a polysaccharide and water to obtain a polysaccharide solution D; mix a protein and water to obtain a protein solution E; mix the polysaccharide solution D, the protein solution E and lactoferrin to obtain a protein-polysaccharide mixture F; Mix the water-in-oil primary emulsion C and the protein-polysaccharide mixture F and perform a second emulsification treatment to obtain an emulsion G.

7. The preparation method of the all-nutrition milk for improving vitamin stability according to claim 6, characterized in that, The inner aqueous phase solution A is specifically prepared by the following steps: Dissolve the thickener in the buffer solution by stirring at 400-1000 rpm for 10-50 min at 50-80 °C; then add the water-soluble vitamins and the first carbohydrate and stir at 400-1000 rpm for 5-15 min at 20-50 °C to obtain the inner aqueous phase solution A; Preferably, the oil phase solution B is specifically prepared by the following steps: First mix the oils and fats and the medium-chain triglycerides to obtain a mixed oil; then add polyglyceryl ricinoleate and soy lecithin to the mixed oil and stir at 400-1000 rpm for 10-40 min at 50-70 °C; then cool to 20-50 °C and add the fat-soluble vitamins and stir at 400-1000 rpm for 5-30 min to obtain the oil phase solution B; Preferably, the water-in-oil primary emulsion C is specifically prepared by the following steps: Add the inner aqueous phase solution A to the oil phase solution B, first shear at a speed of 8000-14000 rpm for 10-20 min; then homogenize at a pressure of 50-80 MPa for 2-4 times to obtain the water-in-oil primary emulsion C; Preferably, the mass ratio of the inner aqueous phase solution A to the oil phase solution B is 1:(3-5).

8. The preparation method of the all-nutrition milk for improving vitamin stability according to claim 6, characterized in that, The polysaccharide solution D is specifically prepared by the following steps: Add the polysaccharide to water, shear at 7000 - 10000 rpm for 10 - 60 min at 50 - 70 °C to dissolve it in water, and obtain the polysaccharide solution D; Preferably, the protein solution E is specifically prepared by the following steps: Add the protein to water, shear at 4000 - 8000 rpm for 5 - 20 min at 40 - 50 °C to dissolve it in water; then heat-treat at 60 - 70 °C and 500 - 1500 rpm for 10 - 30 min to obtain the protein solution E; Preferably, the protein-polysaccharide mixture F is specifically prepared by the following steps: At 60 - 70 °C and 500 - 1500 rpm, add the polysaccharide solution D to the protein solution E, and stir for 5 - 30 min; then add lactoferrin and continue to stir for 5 - 20 min to obtain the protein-polysaccharide mixture F; Preferably, the mass ratio of the polysaccharide solution D to the protein solution E is 1:(3 - 3.5); Preferably, the emulsion G is specifically prepared by the following steps: At 3000 - 8000 rpm, add the water-in-oil primary emulsion C to the protein-polysaccharide mixture F, and shear for 10 - 20 min; then homogenize at a pressure of 20 - 40 MPa for 1 - 2 times to obtain the emulsion G; Preferably, the mass ratio of the water-in-oil primary emulsion C to the protein-polysaccharide mixture F is 1:(15 - 20).

9. The preparation method of the all-nutrition milk for improving vitamin stability according to claim 6, characterized in that, The preparation method further includes the following steps: Mix the emulsion G with minerals, a second carbohydrate, and a third vitamin to obtain an emulsion H; Sterilize the emulsion H to obtain the whole-nutrition milk with improved vitamin stability.

10. The preparation method of the all-nutrition milk for improving vitamin stability according to claim 9, characterized in that, The emulsion H is specifically prepared by the following steps: At 40 - 50 °C and 500 - 2000 rpm, add minerals to the emulsion G and stir for 15 - 30 min; then add the second carbohydrate and the third vitamin and stir for 2 - 10 min to obtain the emulsion H; Preferably, the pH of the emulsion H is 6.5 - 7.5; Preferably, the sterilization temperature is 105 - 121 °C, and the sterilization time is 8 - 15 min.

Images