Acid-resistant neutral modified milk and preparation method thereof

Abstract

The invention discloses acid-resistant neutral modified milk and a preparation method thereof, the modified milk comprises the following components in percentage by mass: 5-65% of water, 20-80% of milk, 5-15% of single cream, 0-6% of milk powder, 2-12% of white granulated sugar, 0.3-0.9% of an emulsifier, 0.1-0.7% of a thickener and 0.5-2.2% of an acidity regulator, the acidity regulator is prepared from 0.3-1% of potassium citrate, 0.1-0.5% of dipotassium phosphate, 0.1-0.5% of sodium citrate, 0.1-0.5% of sodium citrate, 0.1-0.5% of sodium citrate, 0.1-0.5% of sodium citrate, 0.1-0.5% of sodium citrate, 0.1-0.5% of sodium citrate, and the balance of water. The cleaning agent is prepared from the following components in percentage by weight: 0.05 to 0.5 percent of sodium tripolyphosphate, 0.02 to 0.1 percent of sodium hexametaphosphate and The modified milk disclosed by the invention can be placed in fruit milk tea (obvious in sourness) with the pH of more than 4.6 for more than 2 hours at normal temperature without flocculation and layering; and after being placed for more than 1 hour at normal temperature under the acidic condition that the pH value is 3.4-3.8, part of the areas are extremely slightly flocculated, and the state and the taste are not influenced by shaking up.

Description

Technical Field

[0001] The invention relates to an acid-resistant neutral modulated milk and a preparation method thereof, belonging to the technical field of dairy product processing. Background Art

[0002] Formulated milk is a liquid product made from at least 80% raw bovine (or goat) milk or reconstituted milk, with other ingredients, food additives, or nutritional fortifiers added, and then sterilized or sterilized. Formulated milk represents a product of the diversification of dairy products. Through scientific formulation and process optimization, it balances nutritional, taste, and functionality. Its core value lies in satisfying consumers' personalized preferences, rather than being a "replacement" or "downgrade" of pure milk.

[0003] In the street drink industry, combining fruit and milk tea is becoming a new innovation for street drink brands. However, when acidic fruit tea (pH 3.5-4.5) is mixed with milk, milk proteins (such as casein) tend to aggregate at their isoelectric point (pH ≈ 4.6) in a low pH environment, leading to irreversible flocculation and stratification. This phenomenon not only affects the appearance and taste of the product but also reduces the nutritional efficiency of the dairy product.

[0004] In order to improve the acid resistance of reconstituted milk, many explorations have been made in the prior art, such as using acid-resistant non-dairy creamer (powdered oil) or developing acid-resistant powdered oil to replace milk. Patent CN119235000A discloses a method for preparing acid-resistant non-dairy creamer, which replaces milk protein by adding acid-resistant modified starch and emulsifier stabilizers such as gum arabic, and uses glucose syrup with better film-forming properties as a wall material to prepare non-dairy creamer with good acid resistance. The non-dairy creamer is expected to be used in acid-resistant fruit tea beverages to improve the stability of fruit tea, but it will also limit the flavor of fruit milk tea, seriously lack milk flavor, and greatly reduce the nutritional value; Patent CN109984210A discloses a method for preparing acid-resistant powdered oil, which protects protein by adding colloids to avoid full contact with acidic solution, thereby preventing or delaying protein flocculation. The use of such powdered oil will also cause problems such as low nutritional value and poor flavor of the product. Patent CN119632094A proposes a method for preparing a milk tea base milk. By screening suitable emulsifiers, thickeners and acidity regulators, the product has a certain acid resistance and can be used in fruit milk tea drinks with fruit juice. Although this method seems to be able to overcome the above-mentioned defects, from the specific embodiment, the milk tea base milk still needs to rely on the addition of vegetable oils, and although the milk tea base milk can withstand acids with lower pH, its overall stability is poor. Even if refrigerated, its shelf life can only reach about 7 months. Due to the addition of vegetable oil, the product also has problems such as low nutritional value and poor flavor, and goes against the industry trend of "de-dairy creamer" and cannot be added to fruit milk tea drinks as a substitute for milk.

[0005] With the rapid development of the beverage industry, customers and consumers are pursuing beverages that are healthy, attractive, and delicious, while also being more conveniently available through takeout delivery. Therefore, ready-made drinks combining fruit and milk tea need to be kept under acidic conditions for at least 1-2 hours to prevent protein denaturation (flocculation) during delivery and consumption, which would affect appearance and taste. Therefore, developing a formula milk with high health attributes, high nutritional value, good taste and flavor, and strong acid resistance has become a research focus. Summary of the Invention

[0006] To address these issues, the present invention aims to provide an acid-resistant, neutral formula milk and its preparation method, addressing the poor acid resistance, insufficient flavor, and inadequate stability of existing formula milks without added vegetable fat. The formula milk provided by the present invention is stable in acidic fruit milk tea applications, offers high nutritional value, and offers excellent taste and flavor, facilitating product upgrades for brands.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides an acid-resistant neutral modulated milk. The modulated milk comprises, by weight percentage, 5-65% water, 20-80% milk, 5-15% cream, 0-6% milk powder, 2-12% white sugar, 0.3-0.9% emulsifier, 0.1-0.7% thickener and 0.5-2.2% acidity regulator, wherein the acidity regulator is composed of 0.3-1% potassium citrate, 0.1-0.5% dipotassium hydrogen phosphate, 0.05-0.5% sodium tripolyphosphate, 0.02-0.1% sodium hexametaphosphate and 0.02-0.1% sodium carbonate.

[0008] In one embodiment of the present invention, the added amount of the acidity regulator is preferably 0.84-2.06%, calculated by mass percentage, consisting of 0.5-1%, 0.2-0.5% dipotassium hydrogen phosphate, 0.1-0.4% sodium tripolyphosphate, 0.02-0.08% sodium hexametaphosphate and 0.02-0.08% sodium carbonate.

[0009] In one embodiment of the present invention, the added amount of the emulsifier is 0.3-0.8%, calculated by mass percentage, and consists of 0.1-0.3% of mono- and diglycerol fatty acid esters, 0.1-0.25% of diacetyl tartaric acid mono- and diglycerides, 0.05-0.15% of sodium stearoyl lactylate and 0.05-0.1% of Tween 60.

[0010] In one embodiment of the present invention, the thickener is added in an amount of 0.13-0.6% by mass, and consists of 0.1-0.4% sodium carboxymethyl cellulose, 0.01-0.1% gellan gum and 0.02-0.1% xanthan gum.

[0011] In one embodiment of the present invention, the modulated milk comprises, by mass percentage, 20-65% water, 20-80% UHT whole milk, 5-15% cream, 2-6% milk powder, 2-12% white sugar, 0.3-0.8% emulsifier, 0.13-0.6% thickener and 0.5-2.1% acidity regulator.

[0012] In one embodiment of the present invention, the modulated milk comprises, by mass percentage, 5-30% water, 40-80% pasteurized fresh milk, 5-15% cream, 2-6% milk powder, 2-12% white sugar, 0.3-0.8% emulsifier, 0.13-0.6% thickener and 0.5-2.1% acidity regulator.

[0013] The present invention also discloses a method for preparing the above-mentioned modulated milk, comprising the following steps:

[0014] (1) Milk powder hydration: Add milk powder to 60-70°C hot water and stir until completely dissolved;

[0015] (2) emulsion mixing: adding UHT whole milk and cream to the emulsion in step (1) in sequence, and stirring evenly to obtain a mixed solution;

[0016] (3) Powder dissolution: add emulsifier, thickener, acidity regulator and white sugar to the mixed solution of step (2) in sequence, and continue stirring until evenly distributed;

[0017] (4) Pre-shearing treatment: the mixed solution of step (3) was subjected to high-speed shear stirring for 3 minutes;

[0018] (5) Sterilization: After adding water and adjusting the weight, steam sterilize at 141-143℃ for 5-6 seconds;

[0019] (6) Homogenization: The sterilized mixed solution obtained in step (5) is subjected to high-pressure homogenization;

[0020] (7) Cooling and filling: The mixed solution homogenized in step (6) is cooled to room temperature and aseptically filled.

[0021] In one embodiment of the present invention, the mass ratio of the milk powder and water in step (1) is 1:5.

[0022] In one embodiment of the present invention, the temperature of the mixed solution in step (3) is maintained at 65-68°C.

[0023] In one embodiment of the present invention, the rotation speed during shearing in step (4) is 5000-10000 rpm.

[0024] In one embodiment of the present invention, the homogenization pressure in step (6) is: the secondary pressure is 30 bar, the primary pressure is 90-120 bar; the homogenization rate is 20 L / H-6 T / H.

[0025] The present invention also discloses an application of the acid-resistant neutral modulated milk in street drinks.

[0026] In one embodiment of the present invention, the street drink includes any one of fruit milk tea, fruit milk shake, fruit smoothie, etc.

[0027] Beneficial effects:

[0028] (1) The present invention prepares a modulated milk that meets the modulated milk standard by compounding milk, cream, milk powder and water, and adding a compounded emulsifier, thickener and acidity regulator to the aroma. The neutral modulated milk of the present invention does not contain essence and plant fat, has a rich and natural frankincense, and is suitable for mixing with fruits and tea. The addition of emulsifiers, thickeners and acidity regulators can significantly improve the emulsion stability and acid resistance of the modulated milk. The modulated milk of the present invention can be placed in fruit milk tea (with obvious sour taste) with a pH value greater than 4.6 at room temperature for more than 2 hours without flocculation and stratification; it can be placed at room temperature under acidic conditions of pH 3.4-3.8 for more than 1 hour, with some areas very slightly flocculating, and shaking it well does not affect the state and taste. If it is stored under refrigerated conditions, the street drinking state can be maintained for a longer period of time.

[0029] (2) The present invention selects mono- and diglycerol fatty acid esters, diacetyl tartaric acid mono- and diglycerol esters, sodium stearoyl lactylate, and Tween to form a compound emulsifier. The compound emulsifier can effectively prevent the aggregation of fat globules in the emulsion during collision, reduce the surface tension between the fat globules and the aqueous phase, and maintain the stability and acid resistance of the emulsion. In the present invention, the compound emulsifier also needs to have a certain hydrophobicity, but the hydrophobicity cannot be too high, as too high a hydrophobicity will cause milk fat phase droplets, thereby affecting the acid resistance and stability of the emulsion.

[0030] (3) The amount, type, and ratio of thickeners also have a significant impact on the stability and acid resistance of the formulated emulsion. The present invention significantly improves the stability and acid resistance of the emulsion by limiting the amount of thickener added to a specific range and selecting a specific type and ratio of thickeners for compounding. Although reducing the amount or type of thickener added helps improve stability, the acid resistance is significantly worse.

[0031] (4) The type and amount of compounded acidity regulator have little effect on the stability of the formulated milk, but have a more obvious effect on its acid resistance. The present invention obtains a formulated milk with good stability, flavor and acid resistance by selecting a specific type and proportion of acidity regulators for compounding.

[0032] (5) The acid-resistant neutral modulated milk of the present invention is widely used in freshly made acidic beverages such as fruit milk tea, fruit milkshake, and fruit smoothie, meeting consumers' multiple demands for health, taste, and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Refers to the actual pictures of the modulated milk and freshly made fruit milk tea prepared according to the method of Example 1 of the present invention.

[0034] Figure 2 These are pictures of the modulated milk prepared in Example 1 used under different pH conditions.

[0035] Figure 3 These are pictures of the modulated milks of Comparative Example 3, Comparative Example 11 and Comparative Example 12 used at pH 4.6 and placed at room temperature. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention are further explained in detail through the following examples, but the scope of the present invention is not limited thereto.

[0037] The milk involved in the examples and comparative examples of the present invention is UHT room temperature whole milk, the milk powder is domestic whole milk powder, the cream is frozen cream with a fat content of 40%, and the other additives are conventional commercially available raw materials.

[0038] Performance testing:

[0039] Observation of emulsion stability: Place the sterile bottle containing the emulsion in a constant temperature box at room temperature and 37℃, and observe whether the emulsion has stratification or flocculation (fish-like) state.

[0040] Drink recipe: 10-25g NFC yellow lemon juice + 200g jasmine green tea soup + 30g syrup + 120g ice cubes + 100g acid-resistant milk.

[0041] Preparation method: First prepare jasmine green tea soup (add 40g tea leaves to 1000g 75℃ hot water, brew for 7 minutes, drain the tea leaves, add 600g ice cubes, stir until the ice flowers melt and set aside); then prepare NFC yellow lemon juice (cut fresh yellow lemons, juice only the pulp, filter out the clear juice and set aside); add NFC yellow lemon juice, syrup, tea soup and ice cubes in the mixing cup in turn, shake well, then quickly pour in acid-resistant mixing milk, and stir quickly with a stirring spoon.

[0042] Flavor and taste evaluation: feel the sourness, milkiness and thickness of the mouthfeel.

[0043] Evaluation Dimensions Scoring criteria (1 to 5 points) sour 1 = almost no; 3 = sour; 5 = clearly sour milky flavor 1 = too much milk flavor / too light; 3 = slightly more milk flavor / slightly light; 5 = soft / balanced with fruit flavor Thickness of taste 1 = Thick / Not Smooth; 3 = Rich / Smooth; 5 = Light / Smooth Scoring Rules 1 point = poor, 2 points = poor, 3 points = fair, 4 points = good, 5 points = excellent

[0044] Observation of beverage pH and stability: Use a pH meter to measure the pH of the freshly prepared beverage; place the freshly prepared beverage in a room temperature or refrigerator, and observe the condition of the beverage every 20 minutes to see if there is flocculation or water dripping at the bottom. The acid resistance time refers to the time from the time the beverage is prepared to the time when slight local flocculation occurs.

[0045] Example 1

[0046] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.42% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60. The thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0047] A method for preparing the above-mentioned modulated milk comprises the following steps:

[0048] (1) Milk powder hydration: Add milk powder (powder to water mass ratio 1:5) to hot water at 60-70°C and stir until completely dissolved;

[0049] (2) emulsion mixing: adding UHT whole milk and cream to the emulsion in step (1) in sequence, and stirring evenly to obtain a mixed solution;

[0050] (3) Powder dissolution: add emulsifier, thickener, acidity regulator and white sugar to the mixed solution (65-68°C) of step (2) in sequence and continue stirring until evenly mixed;

[0051] (4) Pre-shearing treatment: The mixed solution of step (3) was sheared and stirred at high speed (8000 rpm) for 3 min;

[0052] (5) Sterilization: After adding water and adjusting the weight, steam sterilize at 141-143℃ for 5-6 seconds;

[0053] (6) Homogenization: The sterilized mixed solution obtained in step (5) is subjected to high-pressure homogenization, with a secondary pressure of 30 bar, a primary pressure of 90 bar, and a homogenization rate of 20 L / H;

[0054] (7) Cooling and filling: The mixed solution homogenized in step (6) is cooled to room temperature and aseptically filled.

[0055] A method for preparing an acidic fruit milk tea beverage comprises the following steps:

[0056] (1) Prepare jasmine green tea (add 40g tea leaves to 1000g hot water at 75°C, brew for 7 minutes, drain the tea leaves, add 600g ice cubes, and stir until the ice cubes melt).

[0057] (2) Prepare NFC yellow lemon juice (cut fresh yellow lemons, squeeze only the pulp, and filter out the clear juice for later use);

[0058] (3) Add 10-25g NFC yellow lemon juice, 30g syrup, 200g tea and 120g ice cubes to the mixing cup and shake well;

[0059] (4) Quickly pour in 100g of acid-resistant modified milk (such as Figure 1 ), stir quickly with a stirring spoon, and the prepared drink is as follows Figure 1 and Figure 2 .

[0060] The physical and chemical indicators of the modulated emulsion obtained in Example 1 were: 2.8% protein, 6% fat, and pH 7.2; the emulsion was relatively stable, and its refrigerated shelf life could reach 9 months; when mixed with different amounts of yellow lemon juice, the sensory results were shown in Table 1. When 22.5 g of yellow lemon juice was added, the pH of the overall beverage could reach 4.6, with a distinct sour taste, a distinct lemon flavor, a natural and fresh milk flavor, and a slightly refreshing taste. It did not clump or separate when stored at room temperature for more than 2.5 hours, and did not clump or separate when stored in the refrigerator for up to 6 hours.

[0061] Example 2

[0062] The difference between Example 2 and Example 1 is that the proportions of the components of the modulated milk are different.

[0063] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 27.22% of water, 50% of UHT whole milk, 12% of cream, 4% of milk powder, 4% of white sugar, 0.6% of an emulsifier, 0.5% of a thickener, and 1.68% of an acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.15% of diacetyl tartaric acid mono- and diglycerides, 0.15% of sodium stearoyl lactylate, and 0.1% of Tween 60. The thickener comprises 0.35% of sodium carboxymethyl cellulose, 0.06% of gellan gum, and 0.09% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.3% of sodium tripolyphosphate, 0.02% of sodium hexametaphosphate, and 0.06% of sodium carbonate.

[0064] The physical and chemical indicators of the modulated emulsion obtained in Example 2 are: 3% protein, 7.5% fat, and pH 7.4; the emulsion is relatively stable, and the refrigerated shelf life can reach 9 months; under the application condition of pH 4.6, it has a distinct sour taste, a distinct lemon flavor, a slightly strong milk flavor, and a slightly mellow taste. It does not flocculate or delaminate when placed at room temperature for more than 3 hours, and does not flocculate or delaminate when placed in the refrigerator for up to 6 hours.

[0065] Example 3

[0066] The difference between Example 3 and Example 1 is that the components and proportions of the milk raw materials in the reconstituted milk are different, mainly because pasteurized fresh milk is used to completely replace pure milk and milk powder.

[0067] The invention discloses an acid-resistant neutral modulated milk, which comprises, by weight percentage, 80% of pasteurized fresh milk, 8% of cream, 5.42% of water, 4% of white sugar, 0.5% of an emulsifier, 0.4% of a thickener, and 1.68% of an acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate, and 0.1% of Tween 60. The thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum, and 0.06% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate, and 0.05% of sodium carbonate.

[0068] The physical and chemical properties of the prepared emulsion obtained in Example 3 were as follows: protein 2.8%, fat 6%, and pH 7.0. The emulsion was very stable, with a refrigerated shelf life of up to 12 months. At pH 4.6, it exhibited a distinct sourness, a distinct lemony flavor, a fresh and rich milky flavor, and a light, slightly thin mouthfeel. It remained lint-free for >2 hours at room temperature and up to 5 hours after refrigeration. Its overall acid resistance was slightly inferior to that of Example 1.

[0069] Comparative Example 1

[0070] The difference between Comparative Example 1 and Example 1 is that the ratio of the milk raw materials for the formula milk is different, and the rest remains unchanged.

[0071] The invention discloses an acid-resistant neutral modulated milk, which comprises, by weight percentage, 77.42% of water, 10% of milk powder, 6% of cream, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator; wherein the emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60; the thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum; and the acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0072] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 1 are: protein 2.6%, fat 5%, pH 7.0; the emulsion stability deteriorates, the denatured protein in the milk powder is easily cross-linked, the emulsion is more likely to aggregate and stratify, and the refrigerated shelf life is nearly 4 months; during the shelf life, under the application condition of pH 4.6, the sour taste is obvious, the lemon flavor is obvious, the milk flavor is rich but not fresh (the milk powder flavor is heavier), and the mouthfeel is thick; no flocculation or stratification occurs when placed at room temperature for more than 1.5 hours, and no flocculation or stratification occurs when placed in the refrigerator for up to 4 hours.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 1 is that the components and proportions of the emulsifiers in the modulated milk are different.

[0075] The invention discloses an acid-resistant neutral modulated milk, which comprises, by weight percentage, 40.42% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator. The emulsifier comprises 0.4% of mono- and diglycerol fatty acid esters and 0.1% of sucrose fatty acid ester (HLB15); the thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum; and the acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0076] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 2 are: protein 2.8%, fat 6%, pH 7.2; the emulsion stability is general, and bottom water separation is more likely to occur. The refrigerated shelf life can reach 4 months; under the application condition of pH 4.6, the acidity is obvious, the lemon flavor is obvious, the milk flavor is natural and fresh, the taste is slightly dry, and no flocculation or stratification occurs when placed at room temperature for more than 1 hour, and no flocculation or stratification occurs when placed in the refrigerator for up to 3 hours.

[0077] Comparative Example 3

[0078] The difference between Comparative Example 3 and Example 1 is that the amount of emulsifier added and the component ratio in the modulated milk are different.

[0079] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.77% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.15% of an emulsifier, 0.4% of a thickener, and 1.68% of an acidity regulator. The emulsifier comprises 0.05% of mono- and diglycerol fatty acid esters, 0.05% of diacetyl tartaric acid mono- and diglycerol esters, 0.025% of sodium stearoyl lactylate, and 0.025% of Tween 60. The thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum, and 0.06% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate, and 0.05% of sodium carbonate.

[0080] The physicochemical properties of the modified emulsion obtained in Comparative Example 3 were: 2.8% protein, 6% fat, and a pH of 7.2. The emulsion had poor stability, with a refrigerated shelf life of up to two months. At a pH of 4.6, it exhibited a distinct sourness and lemon flavor, a slightly powdery texture, and a milky, less refreshing taste. It began to flocculate and stratify after approximately 0.5 hours at room temperature, but remained so for up to one hour after refrigeration. This suggests that the emulsifier dosage was too low, resulting in insufficient coating of the emulsion droplet surface and significant environmental impact, which directly impacted its application in the product. Acid resistance in neutral modified emulsions requires good emulsification stability.

[0081] Comparative Example 4

[0082] The difference between Comparative Example 4 and Example 1 is that the amount of emulsifier added and the component ratio in the modulated milk are different.

[0083] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 39.87% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 1.05% of an emulsifier, 0.4% of a thickener, and 1.68% of an acidity regulator. The emulsifier comprises 0.45% of mono- and diglycerol fatty acid esters, 0.3% of diacetyl tartaric acid mono- and diglycerides, 0.15% of sodium stearoyl lactylate, and 0.15% of Tween 60. The thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum, and 0.06% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate, and 0.05% of sodium carbonate.

[0084] The physicochemical properties of the prepared emulsion obtained in Comparative Example 4 were: 2.8% protein, 6% fat, and a pH of 7.2. The emulsion exhibited good stability and a refrigerated shelf life of up to 12 months. However, at a pH of 4.6, the emulsion exhibited a distinct sourness with a slight lemony flavor, a less refreshing aroma, and a perceived emulsifier odor. The emulsion began to flocculate and stratify after approximately one hour at room temperature, but remained so for up to two hours after refrigeration. This suggests that the emulsifier dosage was too high, leading to competitive adsorption of proteins on the surface of the emulsion droplets into free proteins, which were susceptible to acid, and reduced the acid resistance of the system.

[0085] Comparative Example 5

[0086] The difference between Comparative Example 5 and Example 1 is that the composition ratio of the emulsifier in the modulated milk is different.

[0087] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.38% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.54% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator; wherein the emulsifier comprises 0.27% of mono- and diglycerol fatty acid esters, 0.09% of diacetyl tartaric acid mono- and diglycerol esters, 0.09% of sodium stearoyl lactylate and 0.09% of Tween 60; the thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum; and the acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0088] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 5 are: protein 2.8%, fat 6%, and pH 7.2; the emulsion stability is slightly worse than that in Example 1, and the refrigerated shelf life can reach 7 months. This is because after the ratio of the emulsifier is changed, the milk fat phase droplets are relatively easier to aggregate due to enhanced hydrophobicity, especially when the temperature fluctuates or it is left standing for a long time; under the application condition of pH 4.6, the acidity is obvious, the lemon flavor is slightly obvious, the aroma is relatively fresh, and the mouthfeel is thicker and slightly suppresses the tea aroma; after being placed at room temperature for about 1.5 hours, flocculation and stratification begin to occur, and flocculation and stratification can be prevented for up to 5 hours when placed in the refrigerator.

[0089] Comparative Example 6

[0090] The difference between Comparative Example 6 and Example 1 is that the component ratios of the emulsifiers in the modulated milk are different.

[0091] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.42% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator; wherein the emulsifier comprises 0.35% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerol esters, 0.025% of sodium stearoyl lactylate and 0.025% of Tween 60; the thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum; and the acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0092] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 6 are: protein 2.8%, fat 6%, and pH 7.2; the emulsion stability is poorer than that in Example 1, and the refrigerated shelf life can reach 5 months; during the process implementation, the emulsion easily produces many dense small bubbles, which affects production; under the application condition of pH 4.6, the sourness is obvious, the lemon flavor is slightly obvious, the aroma is slightly fresh, and the taste is slightly greasy; flocculation and stratification begin to occur after about 1 hour at room temperature, and no flocculation and stratification occur after refrigeration for up to 3 hours.

[0093] Comparative Example 7

[0094] The difference between Comparative Example 7 and Example 1 is that the components of the thickener in the modulated milk are different (sodium carboxymethyl cellulose is not added).

[0095] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.72% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.1% of thickener and 1.68% of acidity regulator; wherein the emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60; the thickener comprises 0.04% of gellan gum and 0.06% of xanthan gum; and the acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0096] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 7 are: 2.8% protein, 6% fat, and pH 7.2; the emulsion has good stability and a refrigerated shelf life of up to 12 months; under the application condition of pH 4.6, it has a distinct sour taste, a distinct lemon flavor, a general milk flavor, a slightly thin and slightly sticky taste, and no flocculation or stratification occurs when placed at room temperature for more than 1 hour, and no flocculation or stratification occurs when placed in the refrigerator for up to 2 hours.

[0097] Comparative Example 8

[0098] The difference between Comparative Example 8 and Example 1 is that the components of the thickener in the modulated emulsion are different (xanthan gum and gellan gum are not added).

[0099] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.52% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.3% of thickener and 1.68% of acidity regulator; wherein the emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerol esters, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60; the thickener comprises 0.3% of sodium carboxymethyl cellulose; and the acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0100] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 8 are: protein 2.8%, fat 6%, pH 7.2; the emulsion stability is general, and bottom water separation is more likely to occur. The refrigerated shelf life can reach 6 months; under the application condition of pH 4.6, the acidity is obvious, the lemon flavor is obvious, the milk flavor is natural and fresh, the mouthfeel is thin, and no flocculation or stratification occurs when placed at room temperature for more than 1.5 hours, and no flocculation or stratification occurs when placed in the refrigerator for up to 3 hours.

[0101] Comparative Example 9

[0102] The difference between Comparative Example 9 and Example 1 is that the ratio of the thickener in the modulated milk is different.

[0103] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.12% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.7% of thickener and 1.68% of acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60. The thickener comprises 0.45% of sodium carboxymethyl cellulose, 0.125% of gellan gum and 0.125% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0104] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 9 are: protein 2.8%, fat 6%, pH 7.2; the emulsion stability is general, and the refrigerated shelf life can reach 3 months. This is because the colloid easily forms gel drainage phenomenon. It can be used normally if shaken well in a short period of time; after a long storage time, the emulsion droplets tend to form small particles, affecting the sensory organs and taste; under the application condition of pH 4.6, the sourness is obvious, the lemon flavor is obvious, the milk flavor is affected by the taste and appears not fresh, the mouthfeel is thick (strong gelatinous feeling), and no flocculation or stratification occurs when placed at room temperature for more than 3 hours, and no flocculation or stratification occurs when placed in the refrigerator for up to 8 hours.

[0105] Comparative Example 10

[0106] The difference between Comparative Example 10 and Example 1 is that the ratio of the thickener in the modulated milk is different.

[0107] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.42% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60. The thickener comprises 0.15% of sodium carboxymethyl cellulose, 0.125% of gellan gum and 0.125% of xanthan gum. The acidity regulator comprises 0.9% of potassium citrate, 0.4% of dipotassium hydrogen phosphate, 0.28% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0108] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 10 are: protein 2.8%, fat 6%, pH 7.2; the emulsion stability is general, and the refrigerated shelf life can reach 6 months; under the application condition of pH 4.6, the sourness is obvious, the lemon flavor is obvious, the milk flavor is affected by the taste and appears not fresh, the mouthfeel is slightly thick (strong gelatinous feeling), and no flocculation or stratification occurs when placed at room temperature for more than 1.5 hours, and no flocculation or stratification occurs when placed in the refrigerator for up to 4 hours.

[0109] Comparative Example 11

[0110] The difference between Comparative Example 11 and Example 1 is that the ratio of the acidity regulator in the modulated milk is different.

[0111] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 41.65% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 0.45% of acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60. The thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum. The acidity regulator comprises 0.2% of potassium citrate, 0.15% of dipotassium hydrogen phosphate, 0.06% of sodium tripolyphosphate, 0.02% of sodium hexametaphosphate and 0.02% of sodium carbonate.

[0112] The physical and chemical indicators of the modulated milk obtained in Comparative Example 11 are: protein 2.8%, fat 6%, pH 6.8; the emulsion is relatively stable, and the refrigerated shelf life can reach 9 months; under the application condition of pH 4.6, the sourness is obvious, the lemon flavor is obvious, the milk flavor is natural and fresh, and the taste is slightly refreshing. It will flocculate and stratify after 0.5 hours at room temperature, and will not flocculate and stratify after refrigerated storage for 1.5 hours.

[0113] Comparative Example 12

[0114] The difference between Comparative Example 12 and Example 1 is that the components and proportions of the acidity regulator in the modulated milk are different.

[0115] The invention discloses an acid-resistant neutral modulated milk, which comprises, by weight percentage, 41.1% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1% of acidity regulator; wherein the emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerol esters, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60; the thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum; and the acidity regulator comprises 0.9% of potassium citrate, 0.05% of sodium hexametaphosphate and 0.05% of sodium carbonate.

[0116] The physical and chemical indicators of the modulated milk obtained in Comparative Example 12 are: protein 2.8%, fat 6%, pH 6.8; the emulsion is relatively stable, and the refrigerated shelf life can reach 9 months; under the application condition of pH 4.6, the sourness is obvious, the lemon flavor is obvious, the milk flavor is natural and fresh, the mouthfeel is slightly thick, and flocculence and stratification appear after being placed at room temperature for about 1 hour, and flocculence and stratification do not appear after being placed in the refrigerator for up to 2 hours.

[0117] Comparative Example 13

[0118] The difference between Comparative Example 13 and Example 1 is that the components and proportions of the acidity regulator in the modulated milk are different.

[0119] The invention discloses an acid-resistant neutral reconstituted milk, which comprises, by weight percentage, 40.42% of water, 40% of UHT whole milk, 8% of cream, 5% of milk powder, 4% of white sugar, 0.5% of emulsifier, 0.4% of thickener and 1.68% of acidity regulator. The emulsifier comprises 0.2% of mono- and diglycerol fatty acid esters, 0.1% of diacetyl tartaric acid mono- and diglycerides, 0.1% of sodium stearoyl lactylate and 0.1% of Tween 60. The thickener comprises 0.3% of sodium carboxymethyl cellulose, 0.04% of gellan gum and 0.06% of xanthan gum. The acidity regulator comprises 1.465% of potassium citrate, 0.1% of dipotassium hydrogen phosphate, 0.05% of sodium tripolyphosphate, 0.05% of sodium hexametaphosphate and 0.015% of sodium carbonate.

[0120] The physical and chemical indicators of the modulated emulsion obtained in Comparative Example 13 are: protein 2.8%, fat 6%, pH 6.7; the emulsion is relatively stable, and the refrigerated shelf life can reach 9 months; under the application condition of pH 4.6, the sourness is obvious, the lemon flavor is enhanced, the milk flavor is weakened, and the mouthfeel is slightly thick. After about 1.5 hours of storage at room temperature, flocculence and stratification appear, and after refrigerated storage for up to 3 hours, flocculence and stratification do not appear.

[0121] Table 1 Acid resistance performance of the modified milk of Example 1 under different pH conditions

[0122] Lemon juice / g pH of the whole cup sour milky flavor Thickness of taste Acid resistance time at room temperature / h Refrigerated acid resistance time / h 10 5.7 2 2 3 ＞6 ＞10 15 5.1 3 3 4 ＞6 ＞10 20 4.8 4 5 5 ＞4 ＞8 22.5 4.6 5 5 4 ＞2.5 ＞6 25 4.5 5 4 1 ＜0.5 ＜0.5 35 3.7 5 1 2 1 2

[0123] Table 2 Stability of the modified milk of Examples 1 to 3 and Comparative Examples 1 to 13 and acid resistance at pH 4.6

[0124]

[0125]

[0126] Through multi-faceted optimization and adjustment, including the precise use of milk raw materials, emulsification system, thickener, and acidity regulator, the present invention effectively improves the anti-flocculation ability of milk-containing beverages in a low pH application environment. At the same time, it has good nutritional value, natural milk flavor, sour-sweet balance, and a refreshing taste. It can replace milk in the innovation of fruit milk tea products in the street beverage industry.

[0127] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. An acid-resistant neutral formula milk, characterized in that: Calculated by mass percentage, the modulated milk includes 5-65% of water, 20-80% of milk, 5-15% of cream, 0-6% of milk powder, 2-12% of white sugar, 0.3-0.9% of emulsifier, 0.1-0.7% of thickener and 0.5-2.2% of acidity regulator, wherein the acidity regulator is composed of 0.3-1% of potassium citrate, 0.1-0.5% of dipotassium hydrogen phosphate, 0.05-0.5% of sodium tripolyphosphate, 0.02-0.1% of sodium hexametaphosphate and 0.02-0.1% of sodium carbonate.

2. The neutral formula milk according to claim 1, characterized in that Calculated by mass percentage, the added amount of the emulsifier is 0.3-0.8%, and the emulsifier consists of 0.1-0.3% of mono- and diglycerol fatty acid esters, 0.1-0.25% of diacetyl tartaric acid mono- and diglycerides, 0.05-0.15% of sodium stearoyl lactylate and 0.05-0.1% of Tween 60.

3. The neutral modified milk according to claim 1, characterized in that Calculated by mass percentage, the added amount of the thickener is 0.13-0.6%, and the thickener consists of 0.1-0.4% sodium carboxymethyl cellulose, 0.01-0.1% gellan gum and 0.02-0.1% xanthan gum.

4. The neutral modified milk according to claim 1, characterized in that Calculated by mass percentage, the modulated milk comprises 20-65% water, 20-80% UHT whole milk, 5-15% cream, 2-6% milk powder, 2-12% white sugar, 0.3-0.8% emulsifier, 0.13-0.6% thickener and 0.5-2.1% acidity regulator.

5. The neutral formula milk according to claim 1, characterized in that Calculated by mass percentage, the modulated milk includes 5-30% water, 40-80% pasteurized fresh milk, 5-15% cream, 2-6% milk powder, 2-12% white sugar, 0.3-0.8% emulsifier, 0.13-0.6% thickener and 0.5-2.1% acidity regulator.

6. The method for preparing the acid-resistant neutral modified milk according to claim 1, wherein: The following steps are involved: (1) Milk powder hydration: Add milk powder to 60-70°C hot water and stir until completely dissolved; (2) emulsion mixing: adding UHT whole milk and cream to the emulsion in step (1) in sequence, and stirring evenly to obtain a mixed solution; (3) Powder dissolution: add emulsifier, thickener, acidity regulator and white sugar to the mixed solution of step (2) in sequence, keep the temperature of the mixed solution at 65-68°C, and continue stirring evenly; (4) Pre-shearing treatment: The mixed solution of step (3) was subjected to high-speed shear stirring for 3 min at a speed of 5000-10000 rpm; (5) Sterilization: After adding water and adjusting the weight, steam sterilize at 141-143℃ for 5-6 seconds; (6) Homogenization: The sterilized mixed solution obtained in step (5) is subjected to high-pressure homogenization; (7) Cooling and filling: The mixed solution homogenized in step (6) is cooled to room temperature and aseptically filled.

7. The preparation method according to claim 6, characterized in that The mass ratio of the milk powder and water in step (1) is 1:

5.

8. The preparation method according to claim 6, characterized in that The homogenization pressure in step (6) is: the secondary pressure is 30 bar, the primary pressure is 90-120 bar; the homogenization rate is 20 L / H-6 T / H.

9. Use of the acid-resistant neutral modified milk according to any one of claims 1 to 5 in street drinks.

10. The use according to claim 9, characterized in that The street drinks include any one of fruit milk tea, fruit milkshake, fruit smoothie, etc.

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