Natural milk cover pulp and preparation method thereof

Abstract

The invention discloses natural milk cover pulp and a preparation method thereof, and relates to the technical field of milk cover pulp. Bifidobacterium lactis is added into a protective agent, the pH value is adjusted, high-pressure homogenization is performed, and an inner water phase is obtained; melting natural single cream and cheese in a water bath; adding a rosemary extract, tocopherol, beewax and Arabic gum-stearic acid, and uniformly stirring to obtain an oil phase; weighing raw milk and condensed milk, and uniformly stirring to obtain a milk-based solution; adding phytic acid, sodium citrate and succinylated whey protein into the milk-based solution, and homogenizing; adding xanthan gum, locust bean gum and a soapberry bark extract, and uniformly stirring to obtain an outer water phase; adding the inner water phase into the oil phase, and shearing; adding glutamine transaminase, adjusting the pH value, and reacting; performing high-pressure homogenization to obtain W / O emulsion; adding the W / O emulsion into the external water phase, and shearing to obtain W / O / W emulsion; and cooling, homogenizing, sterilizing at low temperature and filling to obtain the natural milk cover pulp.

Description

Technical Field

[0001] This invention relates to the field of milk foam paste technology, specifically a natural milk foam paste and its preparation method. Background Technology

[0002] In recent years, milk foam has been frequently used as a topping in various tea drinks. Its rich flavor and unique taste have made it a favorite among consumers. However, with tea drink brands constantly innovating, milk foam base, as the raw material for milk foam, is facing new challenges. Firstly, there are higher requirements for the taste and flavor of the milk foam base, demanding richer layers and a more unique taste experience. Secondly, the milk foam base needs a more stable system to maintain the consistency of the milk foam's shape before and after whipping, ensuring good stability during milk tea preparation and delivery, providing customers with a perfect dining experience. Finally, from the consumer's perspective, there is an emphasis on developing healthier, cleaner, and more natural milk foam bases, aligning with the popular trend of the health and wellness era.

[0003] To address the above problems, this invention provides a natural milk foam paste and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a natural milk foam paste and its preparation method to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] Step 1: Add the aqueous phase to the oil phase and shear; add transglutaminase, adjust the pH with sodium hydroxide, and react; homogenize under high pressure to obtain a W / O emulsion;

[0007] Step 2: Weigh raw milk and condensed milk, stir well to obtain a milk base solution; add phytic acid, sodium citrate, and succinylated whey protein to the milk base solution and homogenize; then add xanthan gum, locust bean gum, and soap bark extract, stir well to obtain the external aqueous phase;

[0008] Step 3: Add the W / O emulsion to the external aqueous phase, shear to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk foam paste.

[0009] A more optimized method for preparing the inner aqueous phase is as follows: trehalose and resistant dextrin are added to purified water and stirred evenly to obtain a protective agent; Bifidobacterium lactis is added to the protective agent, the pH is adjusted with phytic acid, and the mixture is homogenized under high pressure to obtain the inner aqueous phase.

[0010] A more optimized method for preparing the oil phase is as follows: under a temperature of 50-60℃, natural light cream and cheese are melted in a water bath; rosemary extract, tocopherol, beeswax, and gum arabic-stearic acid are added and stirred evenly to obtain the oil phase.

[0011] A more optimized method for preparing succinylated whey protein is as follows: Weigh whey protein and add it to distilled water, stir until homogeneous to obtain a whey protein solution; slowly add octenyl succinic anhydride to the whey protein solution obtained above, adjust the pH with sodium hydroxide to maintain the pH value stable at 8-9, and stir until homogeneous; react for 25-35 min, centrifuge, wash, adjust the pH value with sodium hydroxide to 6.5-7.5, and dry to obtain succinylated whey protein.

[0012] For optimal results, the pH value should be adjusted to 4-5.

[0013] A more optimized method for preparing gum arabic-stearic acid is as follows: Stearic acid and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride are weighed and added to anhydrous ethanol. The mixture is stirred at 55-65℃ for 25-35 min to obtain an O-acylisourea intermediate. Gum arabic is weighed and added to pure water. The mixture is heated and stirred, and the O-acylisourea intermediate obtained above is slowly added. The mixture is stirred until homogeneous and reacted for 5-7 h. After removing impurities, the mixture is freeze-dried to obtain gum arabic-stearic acid.

[0014] A more optimized gum arabic-stearic acid composition comprises the following components, in parts by weight: 0.6-0.8 parts by weight of stearic acid, 4.61-4.81 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 75-85 parts by weight of anhydrous ethanol, 0.5-1.5 parts by weight of gum arabic, and 95-105 parts by weight of purified water.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. A W / O / W dual emulsion system was constructed, featuring a "two-membrane, three-phase" structure, consisting of an inner aqueous phase, an oil phase, and an outer aqueous phase. The inner aqueous phase encapsulates hydrophilic Bifidobacterium lactis, phytic acid, trehalose, and resistant dextrin, while the oil phase encapsulates lipophilic rosemary extract, tocopherol, and beeswax, effectively protecting bioactive substances of different properties from external environmental influences and improving transport efficiency. Secondly, a two-step emulsification method was employed: the inner aqueous phase was added to the oil phase containing gum arabic-stearic acid as a lipophilic emulsifier to form a W / O emulsion; the W / O emulsion was then added to the outer aqueous phase containing succinylated whey protein as a hydrophilic emulsifier to form a W / O / W emulsion.

[0017] Xanthan gum, locust bean gum, soap bark extract, and transglutaminase are added as thickeners and stabilizers. Furthermore, succinylated whey protein and gum arabic-stearic acid are further bound together through protein-polysaccharide interactions, thereby improving the stability of the milk foam mixture.

[0018] 2. Stearic acid is modified into gum arabic by catalysis of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The carbodiimide group of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride reacts with the carboxyl group of stearic acid to form an O-acylisourea intermediate. The activated carboxyl group of the O-acylisourea intermediate undergoes a nucleophilic substitution reaction with the hydroxyl group of gum arabic to form an ester bond. The hydrophobic stearic acid is grafted onto the hydrophilic gum arabic to obtain amphiphilic gum arabic α-stearic acid as a lipophilic emulsifier.

[0019] Succinyl liver undergoes a nucleophilic substitution reaction with the free amino group of whey protein, introducing a hydrophilic succinyl group into the amphiphilic whey protein, resulting in hydrophilic succinylated whey protein, which can be used as a hydrophilic emulsifier.

[0020] 3. Utilizing the "two-membrane, three-phase" structure of the W / O / W dual emulsion system, antioxidants of different properties are added to the inner aqueous phase, oil phase, and outer aqueous phase. By coating the inner aqueous phase with hydrophilic trehalose and phytic acid, coating the oil phase with lipophilic rosemary extract, tocopherol, and beeswax, and adding hydrophilic phytic acid, sodium citrate, and xanthan gum to the outer aqueous phase, a complete antioxidant network structure is constructed.

[0021] 4. The addition of trehalose and resistant dextrin as protective agents, and phytic acid as an antioxidant, synergistically protects probiotics through different mechanisms of action. Trehalose has a high glass transition temperature of 115-120℃. When the external temperature is lower than the glass transition temperature of trehalose, it interacts with the bacterial cell membrane to form hydrogen bonds, forming a hydrated protective film on the surface of probiotics and maintaining the stability of the three-dimensional structure of the bacteria. Resistant dextrin, as dietary fiber, not only promotes the growth of probiotics, but also regulates intestinal pH, delays protein and fat oxidation, and extends shelf life by producing short-chain fatty acids from the metabolism of resistant dextrin. Phytic acid not only regulates pH and maintains suitable environmental conditions for probiotic growth, but also acts as a chelating agent, chelating divalent and higher-valence metal ions to form chelates, thereby inhibiting the catalytic oxidation of metal ions and extending shelf life; it also reduces the participation of metal ions in free radical reactions, further enhancing the free radical scavenging ability of trehalose. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The sources and types of substances involved in this invention are not particularly limited, and exemplary examples include:

[0024] Trehalose, catalog number 001, is supplied by Jiangsu Yihaotian Biotechnology Co., Ltd.

[0025] The resistant dextrin, catalog number 65768, was provided by Jiangsu Weizhirun Biotechnology Co., Ltd.

[0026] The Bifidobacterium lactis product number is 01, provided by Jiangsu Weizhirun Biotechnology Co., Ltd.

[0027] Phytic acid, catalog number A00473, was supplied by Wuhan Jiyesheng Chemical Co., Ltd.

[0028] Stearic acid, catalog number AHA, is supplied by Shaanxi Xifu Biotechnology Co., Ltd.

[0029] 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, catalog number S30054-25g, is supplied by Shanghai Yuanye Biotechnology Co., Ltd.

[0030] The gum arabic, product number 91478, was provided by Hebei Asia-Pacific Biotechnology Co., Ltd.

[0031] The rosemary extract, catalog number 24346576, was provided by Jiangsu Weizhirun Biotechnology Co., Ltd.

[0032] Tocopherol, catalog numbers 1-9, is supplied by Jiangxi Huayuyuan Biotechnology Co., Ltd.

[0033] The beeswax, product number FL10206, was supplied by Dazhou Branch of Changge Yanyuan Bee Products Co., Ltd.

[0034] The whey protein, catalog number F-21, was supplied by Hebei Kelongduo Biotechnology Co., Ltd.

[0035] Octenyl succinic anhydride, catalog number HY-145942, is supplied by Shanghai Haoyuan Biomedical Technology Co., Ltd.

[0036] Sodium citrate, product number 125, was supplied by Jinan Guocheng Chemical Co., Ltd.

[0037] Xanthan gum, product number 101, is supplied by Hebei AsiaInfo Biotechnology Co., Ltd.

[0038] Locust bean gum, product number 01, is supplied by Hebei Jiuxing Chemical Products Co., Ltd.

[0039] The product code for the soap bark extract is SXLSY-YZSPTQW, and it was provided by Shaanxi Lvshengyuan Biological Products Manufacturing Co., Ltd.

[0040] The transglutaminase, catalog number 02, was supplied by Zhengzhou Gebes Food Additives Co., Ltd.

[0041] Example 1: A method for preparing a natural milk foam paste;

[0042] Step 1: Preparation of internal aqueous phase

[0043] Add 1g of trehalose and 1g of resistant dextrin to 85mL of purified water and stir well to obtain a protective agent; add 5g of Bifidobacterium lactis to the protective agent obtained above, adjust the pH value to 4 with phytic acid, and homogenize under high pressure to obtain the inner aqueous phase;

[0044] Step 2: Preparation of the oil phase

[0045] S1: Weigh 0.6 g stearic acid and 4.61 g 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and add them to 75 mL anhydrous ethanol. Stir at 55 °C for 25 min to obtain O-acylisourea intermediate. Weigh 0.5 g gum arabic and add it to 95 mL pure water. Heat and stir, then slowly add the O-acylisourea intermediate obtained above. Stir until homogeneous and react for 5 h. Remove impurities and freeze-dry to obtain gum arabic-stearic acid.

[0046] S2: At a temperature of 50℃, melt 30g of natural light cream and 10g of cheese in a water bath; add 0.08g of rosemary extract, 0.05g of tocopherol, 0.4g of beeswax, and 0.7g of gum arabic-stearic acid, and stir well to obtain the oil phase;

[0047] Step 3: Preparation of external aqueous phase

[0048] S1: Weigh 6g of whey protein and add it to 94mL of distilled water. Stir well to obtain a whey protein solution. Slowly add 11g of octenyl succinic anhydride to the whey protein solution obtained above. Adjust the pH with 0.5mol / L sodium hydroxide to maintain the pH value at 8. Stir well. React for 25min, centrifuge, wash, adjust the pH value to 6.5 with 0.5mol / L sodium hydroxide, and dry to obtain succinylated whey protein.

[0049] S2: Weigh 30g of raw milk and 9g of condensed milk, and stir evenly at 45℃ to obtain a milk base solution; add 0.07g of phytic acid, 0.09g of sodium citrate, and 1.5g of succinylated whey protein to the above-obtained milk base solution, and homogenize at 5000rpm for 4min; then add 0.09g of xanthan gum, 0.04g of locust bean gum, and 0.02g of soap bark extract, and stir evenly to obtain the external aqueous phase;

[0050] Step 4: Constructing a W / O / W emulsion

[0051] S1: At 5000 rpm, 25 mL of the aqueous phase was added to 65 mL of the oil phase, and then sheared at 19000 rpm for 2 min; 0.01 g of transglutaminase was added, and the pH was adjusted to 6.5 with 0.5 mol / L sodium hydroxide, and the reaction was carried out for 25 min; then, the mixture was homogenized under high pressure at 25 MPa for 1 min to obtain the W / O emulsion.

[0052] S2: Add 100 mL of the W / O emulsion obtained above to 145 mL of external aqueous phase, and shear for 2 min at 10000 rpm to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk cap slurry.

[0053] Example 2: A method for preparing a natural milk foam paste;

[0054] Step 1: Preparation of internal aqueous phase

[0055] Add 2g of trehalose and 2g of resistant dextrin to 90mL of purified water and stir well to obtain a protective agent; add 6g of Bifidobacterium lactis to the protective agent obtained above, adjust the pH value to 4.5 with phytic acid, and homogenize under high pressure to obtain the inner aqueous phase;

[0056] Step 2: Preparation of the oil phase

[0057] S1: Weigh 0.7g stearic acid and 4.71g 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and add them to 80mL of anhydrous ethanol. Stir at 60℃ for 30min to obtain O-acylisourea intermediate. Weigh 1g gum arabic and add it to 100mL of pure water. Heat and stir, then slowly add the O-acylisourea intermediate obtained above. Stir until homogeneous and react for 6h. Remove impurities and freeze-dry to obtain gum arabic-stearic acid.

[0058] S2: At a temperature of 55℃, melt 35g of natural light cream and 15g of cheese in a water bath; add 0.09g of rosemary extract, 0.08g of tocopherol, 0.5g of beeswax, and 0.8g of gum arabic-stearic acid, and stir well to obtain the oil phase;

[0059] Step 3: Preparation of external aqueous phase

[0060] S1: Weigh 6.5g of whey protein and add it to 94.5mL of distilled water. Stir well to obtain a whey protein solution. Slowly add 11.5g of octenyl succinic anhydride to the whey protein solution obtained above. Adjust the pH with 0.5mol / L sodium hydroxide to maintain the pH value at 8.5. Stir well. React for 30min, centrifuge, wash, adjust the pH value to 7 with 0.5mol / L sodium hydroxide, and dry to obtain succinylated whey protein.

[0061] S2: Weigh 35g of raw milk and 10g of condensed milk, and stir evenly at 50℃ to obtain a milk base solution; add 0.08g of phytic acid, 0.1g of sodium citrate, and 1.6g of succinylated whey protein to the above-obtained milk base solution, and homogenize at 6000rpm for 5min; then add 0.1g of xanthan gum, 0.05g of locust bean gum, and 0.03g of soap bark extract, and stir evenly to obtain the external aqueous phase;

[0062] Step 4: Constructing a W / O / W emulsion

[0063] S1: At 6000 rpm, 30 mL of the aqueous phase was added to 70 mL of the oil phase, and then sheared at 20000 rpm for 3 min; 0.01 g of transglutaminase was added, and the pH was adjusted to 7 with 0.5 mol / L sodium hydroxide, and the reaction was carried out for 30 min; the mixture was then homogenized under high pressure at 30 MPa for 2 min to obtain the W / O emulsion.

[0064] S2: Add 100 mL of the W / O emulsion obtained above to 150 mL of external aqueous phase, and shear for 3 min at 10000 rpm to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk cap slurry.

[0065] Example 3: A method for preparing a natural milk foam paste;

[0066] Step 1: Preparation of internal aqueous phase

[0067] Add 3g of trehalose and 3g of resistant dextrin to 95mL of purified water and stir well to obtain a protective agent; add 7g of Bifidobacterium lactis to the protective agent obtained above, adjust the pH value to 5 with phytic acid, and homogenize under high pressure to obtain the inner aqueous phase;

[0068] Step 2: Preparation of the oil phase

[0069] S1: Weigh 0.8 g stearic acid and 4.81 g 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and add them to 85 mL of anhydrous ethanol. Stir at 65 °C for 35 min to obtain an O-acylisourea intermediate. Weigh 1.5 g gum arabic and add it to 105 mL of pure water. Heat and stir, then slowly add the O-acylisourea intermediate obtained above. Stir until homogeneous and react for 7 h. Remove impurities and freeze-dry to obtain gum arabic-stearic acid.

[0070] S2: At a temperature of 60℃, melt 40g of natural light cream and 20g of cheese in a water bath; add 0.1g of rosemary extract, 0.1g of tocopherol, 0.6g of beeswax, and 0.9g of gum arabic-stearic acid, and stir well to obtain the oil phase;

[0071] Step 3: Preparation of external aqueous phase

[0072] S1: Weigh 7g of whey protein and add it to 95mL of distilled water. Stir well to obtain a whey protein solution. Slowly add 12g of octenyl succinic anhydride to the whey protein solution obtained above. Adjust the pH with 0.5mol / L sodium hydroxide to maintain the pH value at 9. Stir well. React for 35min, centrifuge, wash, adjust the pH value to 7.5 with 0.5mol / L sodium hydroxide, and dry to obtain succinylated whey protein.

[0073] S2: Weigh 40g of raw milk and 11g of condensed milk, and stir evenly at 55℃ to obtain a milk base solution; add 0.09g of phytic acid, 0.11g of sodium citrate, and 1.7g of succinylated whey protein to the above-obtained milk base solution, and homogenize at 7000rpm for 6min; then add 0.11g of xanthan gum, 0.06g of locust bean gum, and 0.04g of soap bark extract, and stir evenly to obtain the external aqueous phase;

[0074] Step 4: Constructing a W / O / W emulsion

[0075] S1: At 7000 rpm, 35 mL of the aqueous phase was added to 75 mL of the oil phase, and then sheared at 21000 rpm for 4 min; 0.01 g of transglutaminase was added, and the pH was adjusted to 7.5 with 0.5 mol / L sodium hydroxide, and the reaction was carried out for 35 min; under high pressure at 35 MPa, the mixture was homogenized for 3 min to obtain the W / O emulsion.

[0076] S2: Add 100 mL of the W / O emulsion obtained above to 155 mL of external aqueous phase, and shear for 4 min at 10000 rpm to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk cap slurry.

[0077] Comparative Example 1: Without the addition of gum arabic-stearic acid, the rest is the same as in Example 2, and the specific operation is as follows:

[0078] Step 1: Preparation of internal aqueous phase

[0079] Add 2g of trehalose and 2g of resistant dextrin to 90mL of purified water and stir well to obtain a protective agent; add 6g of Bifidobacterium lactis to the protective agent obtained above, adjust the pH value to 4.5 with phytic acid, and homogenize under high pressure to obtain the inner aqueous phase;

[0080] Step 2: Preparation of the oil phase

[0081] At a temperature of 55℃, 35g of natural light cream and 15g of cheese were melted in a water bath; 0.09g of rosemary extract, 0.08g of tocopherol and 0.5g of beeswax were added and stirred evenly to obtain the oil phase;

[0082] Step 3: Preparation of external aqueous phase

[0083] S1: Weigh 6.5g of whey protein and add it to 94.5mL of distilled water. Stir well to obtain a whey protein solution. Slowly add 11.5g of octenyl succinic anhydride to the whey protein solution obtained above. Adjust the pH with 0.5mol / L sodium hydroxide to maintain the pH value at 8.5. Stir well. React for 30min, centrifuge, wash, adjust the pH value to 7 with 0.5mol / L sodium hydroxide, and dry to obtain succinylated whey protein.

[0084] S2: Weigh 35g of raw milk and 10g of condensed milk, and stir evenly at 50℃ to obtain a milk base solution; add 0.08g of phytic acid, 0.1g of sodium citrate, and 1.6g of succinylated whey protein to the above-obtained milk base solution, and homogenize at 6000rpm for 5min; then add 0.1g of xanthan gum, 0.05g of locust bean gum, and 0.03g of soap bark extract, and stir evenly to obtain the external aqueous phase;

[0085] Step 4: Constructing a W / O / W emulsion

[0086] S1: At 6000 rpm, 30 mL of the aqueous phase was added to 70 mL of the oil phase, and then sheared at 20000 rpm for 3 min; 0.01 g of transglutaminase was added, and the pH was adjusted to 7 with 0.5 mol / L sodium hydroxide, and the reaction was carried out for 30 min; the mixture was then homogenized under high pressure at 30 MPa for 2 min to obtain the W / O emulsion.

[0087] S2: Add 100 mL of the W / O emulsion obtained above to 150 mL of external aqueous phase, and shear for 3 min at 10000 rpm to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk cap slurry.

[0088] Comparative Example 2: No succinylated whey protein was added; all other procedures were the same as in Example 2. The specific procedures are as follows:

[0089] Step 1: Preparation of internal aqueous phase

[0090] Add 2g of trehalose and 2g of resistant dextrin to 90mL of purified water and stir well to obtain a protective agent; add 6g of Bifidobacterium lactis to the protective agent obtained above, adjust the pH value to 4.5 with phytic acid, and homogenize under high pressure to obtain the inner aqueous phase;

[0091] Step 2: Preparation of the oil phase

[0092] S1: Weigh 0.7g stearic acid and 4.71g 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and add them to 80mL of anhydrous ethanol. Stir at 60℃ for 30min to obtain O-acylisourea intermediate. Weigh 1g gum arabic and add it to 100mL of pure water. Heat and stir, then slowly add the O-acylisourea intermediate obtained above. Stir until homogeneous and react for 6h. Remove impurities and freeze-dry to obtain gum arabic-stearic acid.

[0093] S2: At a temperature of 55℃, melt 35g of natural light cream and 15g of cheese in a water bath; add 0.09g of rosemary extract, 0.08g of tocopherol, 0.5g of beeswax, and 0.8g of gum arabic-stearic acid, and stir well to obtain the oil phase;

[0094] Step 3: Preparation of external aqueous phase

[0095] Weigh 35g of raw milk and 10g of condensed milk, and stir evenly at 50℃ to obtain a milk-based solution. Add 0.08g of phytic acid, 0.1g of sodium citrate, and 1.6g of succinylated whey protein to the milk-based solution obtained above, and homogenize at 6000rpm for 5min. Then add 0.1g of xanthan gum, 0.05g of locust bean gum, and 0.03g of soap bark extract, and stir evenly to obtain the external aqueous phase.

[0096] Step 4: Constructing a W / O / W emulsion

[0097] S1: At 6000 rpm, 30 mL of the aqueous phase was added to 70 mL of the oil phase, and then sheared at 20000 rpm for 3 min; 0.01 g of transglutaminase was added, and the pH was adjusted to 7 with 0.5 mol / L sodium hydroxide, and the reaction was carried out for 30 min; the mixture was then homogenized under high pressure at 30 MPa for 2 min to obtain the W / O emulsion.

[0098] S2: Add 100 mL of the W / O emulsion obtained above to 150 mL of external aqueous phase, and shear for 3 min at 10000 rpm to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk cap slurry.

[0099] Comparative Example 3: No protective agent was added; all other procedures were the same as in Example 2. The specific operations are as follows:

[0100] Step 1: Preparation of internal aqueous phase

[0101] Add 6g of Bifidobacterium lactis, adjust the pH to 4.5 with phytic acid, homogenize under high pressure to obtain the internal aqueous phase;

[0102] Step 2: Preparation of the oil phase

[0103] S1: Weigh 0.7g stearic acid and 4.71g 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and add them to 80mL of anhydrous ethanol. Stir at 60℃ for 30min to obtain O-acylisourea intermediate. Weigh 1g gum arabic and add it to 100mL of pure water. Heat and stir, then slowly add the O-acylisourea intermediate obtained above. Stir until homogeneous and react for 6h. Remove impurities and freeze-dry to obtain gum arabic-stearic acid.

[0104] S2: At a temperature of 55℃, melt 35g of natural light cream and 15g of cheese in a water bath; add 0.09g of rosemary extract, 0.08g of tocopherol, 0.5g of beeswax, and 0.8g of gum arabic-stearic acid, and stir well to obtain the oil phase;

[0105] Step 3: Preparation of external aqueous phase

[0106] S1: Weigh 6.5g of whey protein and add it to 94.5mL of distilled water. Stir well to obtain a whey protein solution. Slowly add 11.5g of octenyl succinic anhydride to the whey protein solution obtained above. Adjust the pH with 0.5mol / L sodium hydroxide to maintain the pH value at 8.5. Stir well. React for 30min, centrifuge, wash, adjust the pH value to 7 with 0.5mol / L sodium hydroxide, and dry to obtain succinylated whey protein.

[0107] S2: Weigh 35g of raw milk and 10g of condensed milk, and stir evenly at 50℃ to obtain a milk base solution; add 0.08g of phytic acid, 0.1g of sodium citrate, and 1.6g of succinylated whey protein to the above-obtained milk base solution, and homogenize at 6000rpm for 5min; then add 0.1g of xanthan gum, 0.05g of locust bean gum, and 0.03g of soap bark extract, and stir evenly to obtain the external aqueous phase;

[0108] Step 4: Constructing a W / O / W emulsion

[0109] S1: At 6000 rpm, 30 mL of the aqueous phase was added to 70 mL of the oil phase, and then sheared at 20000 rpm for 3 min; 0.01 g of transglutaminase was added, and the pH was adjusted to 7 with 0.5 mol / L sodium hydroxide, and the reaction was carried out for 30 min; the mixture was then homogenized under high pressure at 30 MPa for 2 min to obtain the W / O emulsion.

[0110] S2: Add 100 mL of the W / O emulsion obtained above to 150 mL of external aqueous phase, and shear for 3 min at 10000 rpm to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk cap slurry.

[0111] experiment:

[0112] The stability of the natural milk foam prepared in Examples 1-3 and Comparative Examples 1-3 was evaluated.

[0113] (1) Measurement of average particle size

[0114] The natural milk foam paste was centrifuged to remove fat and obtain an aqueous phase. The natural milk foam paste and the aqueous phase were mixed evenly at a volume ratio of 1:49. The average particle size of the natural milk foam paste was measured using a Nicomp-380ZLS laser particle size analyzer.

[0115] (2) Measurement of Zeta potential

[0116] The natural milk foam paste was centrifuged to remove fat, resulting in an aqueous phase. The natural milk foam paste and the aqueous phase were mixed evenly at a volume ratio of 1:49. The zeta potential of the natural milk foam paste was measured using a Nicomp-380ZLS laser particle size analyzer.

[0117] The data obtained from the above experiment are shown in Table 1 below:

[0118] Table 1

[0119] Average particle size (nm) Zeta potential mV Example 1 246 60 Example 2 245 61 Example 3 247 59 Comparative Example 1 455 43 Comparative Example 2 491 41 Comparative Example 3 418 51

[0120] Conclusion: Through analysis of the above experimental data, the natural milk foam paste prepared in Examples 1-3 of this invention has a smaller particle size, more intense Brownian motion, and more uniform dispersion of milk foam paste particles in the system. Furthermore, according to the DLVO theory, the larger the absolute value of the Zeta potential, the greater the double-layer repulsion, and the easier it is for van der Waals forces and double-layer repulsion to reach equilibrium in the system. The rising and falling trends of both indicate a significant improvement in system stability. In contrast, the natural milk foam paste prepared in Comparative Examples 1-3 has a larger particle size, a smaller absolute value of the Zeta potential, an imperfect emulsification system, and a significantly decreased system stability.

[0121] Comparative analysis of Comparative Example 1 (without gum arabic-stearic acid) and Example 2 shows that, through the catalysis of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride to modify gum arabic with stearic acid, the carbodiimide group of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride reacts with the carboxyl group of stearic acid to form an O-acylisourea intermediate. The activated carboxyl group of the O-acylisourea intermediate undergoes a nucleophilic substitution reaction with the hydroxyl group of gum arabic to form an ester bond, grafting hydrophobic stearic acid onto hydrophilic gum arabic to obtain amphiphilic gum arabic-stearic acid as a lipophilic emulsifier.

[0122] On the one hand, the hydrophilic groups in gum arabic are bonded to the aqueous phase molecules through hydrogen bonds; on the other hand, the lipophilic groups in gum arabic are bonded to the oil phase molecules through hydrophobic interactions; further, a stable interface film is formed through electrostatic-steric hindrance interactions.

[0123] Comparative analysis of Comparative Example 2 (without succinylated whey protein) and Example 2 shows that succinylated whey protein undergoes a nucleophilic substitution reaction with the free amino groups of whey protein, introducing hydrophilic succinylated groups into the amphiphilic whey protein, resulting in hydrophilic succinylated whey protein as a hydrophilic emulsifier; whey protein contains hydrophilic groups and hydrophobic residues, which adsorb at the oil-water interface to form a stable hydrophilic-hydrophobic bilayer structure.

[0124] A W / O / W dual emulsion system with a "two-membrane, three-phase" structure was constructed using a two-step emulsification method. The inner aqueous phase was added to the oil phase containing gum arabic-stearic acid as a lipophilic emulsifier to form a W / O emulsion. The W / O emulsion was then added to the outer aqueous phase containing succinylated whey protein as a hydrophilic emulsifier to form a W / O / W emulsion. Xanthan gum, locust bean gum, soap bark extract, and transglutaminase were added as thickeners and stabilizers. Furthermore, succinylated whey protein and gum arabic-stearic acid were further bound together through protein-polysaccharide interactions, thereby improving the stability of the milk foam.

[0125] Comparative analysis of Comparative Example 3 (without protective agents) and Example 2 shows that the addition of trehalose and resistant dextrin as protective agents synergistically protects probiotics through different mechanisms of action. Trehalose has a glass transition temperature as high as 115-120℃. When the external temperature is lower than the glass transition temperature of trehalose, it interacts with the bacterial cell membrane to form hydrogen bonds, forming a hydrated protective film on the surface of probiotics and maintaining the stability of the three-dimensional structure of the bacteria. As a dietary fiber, resistant dextrin not only promotes the growth of probiotics, but also regulates the intestinal pH value, delays protein and fat oxidation, and extends shelf life by producing short-chain fatty acids from the metabolism of resistant dextrin by probiotics.

[0126] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A natural milk foam paste and its preparation method, characterized in that: Includes the following steps: Step 1: Add the aqueous phase to the oil phase and shear; add transglutaminase, adjust the pH with sodium hydroxide, and react; homogenize under high pressure to obtain a W / O emulsion; Step 2: Weigh raw milk and condensed milk, stir well to obtain a milk base solution; add phytic acid, sodium citrate, and succinylated whey protein to the milk base solution and homogenize; then add xanthan gum, locust bean gum, and soap bark extract, stir well to obtain the external aqueous phase; Step 3: Add the W / O emulsion to the external aqueous phase, shear to obtain W / O / W emulsion; cool, homogenize, sterilize at low temperature, and fill to obtain natural milk foam paste.

2. The method for preparing a natural milk foam paste according to claim 1, characterized in that: The method for preparing the inner aqueous phase is as follows: trehalose and resistant dextrin are added to purified water and stirred evenly to obtain a protective agent; Bifidobacterium lactis is added to the protective agent, the pH value is adjusted with phytic acid, and the mixture is homogenized under high pressure to obtain the inner aqueous phase.

3. The method for preparing a natural milk foam paste according to claim 1, characterized in that: The oil phase is prepared by melting natural light cream and cheese in a water bath at a temperature of 50-60℃; adding rosemary extract, tocopherol, beeswax, and gum arabic-stearic acid, and stirring evenly to obtain the oil phase.

4. The method for preparing a natural milk foam paste according to claim 1, characterized in that: The preparation method of succinylated whey protein is as follows: weigh whey protein and add it to distilled water, stir evenly to obtain a whey protein solution; slowly add octenyl succinic anhydride to the whey protein solution obtained above, adjust the pH with sodium hydroxide to maintain the pH value stable at 8-9, stir evenly; react for 25-35 min, centrifuge, wash, adjust the pH value with sodium hydroxide to 6.5-7.5, dry, and obtain succinylated whey protein.

5. The method for preparing a natural milk foam paste according to claim 2, characterized in that: The pH value is adjusted to 4-5.

6. The method for preparing a natural milk foam paste according to claim 3, characterized in that: The preparation method of gum arabic-stearic acid is as follows: Stearic acid and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride are weighed and added to anhydrous ethanol. Under the condition of 55-65℃, the mixture is stirred for 25-35 min to obtain O-acylisourea intermediate; gum arabic is weighed and added to pure water, heated and stirred, and the O-acylisourea intermediate obtained above is slowly added. The mixture is stirred evenly and reacted for 5-7 h; impurities are removed and the mixture is freeze-dried to obtain gum arabic-stearic acid.

7. The method for preparing a natural milk foam paste according to claim 6, characterized in that: The gum arabic-stearic acid comprises the following components, in parts by weight: 0.6-0.8 parts by weight of stearic acid, 4.61-4.81 parts by weight of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 75-85 parts by weight of anhydrous ethanol, 0.5-1.5 parts by weight of gum arabic, and 95-105 parts by weight of purified water.

8. A natural milk foam paste prepared by the method of any one of claims 1-7.