Foaming agent composition and application thereof in liquid milk

Abstract

The invention relates to a foaming agent composition for dairy products as well as a preparation method and application of the foaming agent composition. The foaming agent composition disclosed by the invention is prepared from the following components in percentage by mass: 1 to 40 percent of protein glutaminase (PG), 30 to 80 percent of curdlan and / or beta-glucan, 1 to 20 percent of maltodextrin, cellulose derivatives and / or sodium polyacrylate and 0.3 to 10 percent of chloride. The invention further relates to a preparation method of the foaming agent composition, a dairy product containing the foaming agent composition, a preparation method of the dairy product and application of the foaming agent composition to improvement of the foamability and milk foam stability of the dairy product.

Description

Technical Field

[0001] This invention belongs to the technical field of food processing, specifically relating to a foaming agent composition for improving the foaming properties and / or foam stability of liquid dairy products, particularly a foaming agent composition containing protein glutaminase, which improves the charge and solubility of proteins in liquid dairy products through enzyme treatment, thereby enhancing their foaming properties and foam stability. Background Technology

[0002] With the popularization and development of tea and coffee culture, the consumption of milk-based coffee drinks has been increasing year by year, and the quality requirements for milk foam are extremely high. Ideal milk foam should have a delicate texture, a smooth mouthfeel, and lasting stability. However, when ordinary liquid milk is frothed, problems such as large foam, rapid defoaming, and milk foam separation often occur, which affect the sensory quality of the final beverage.

[0003] Traditional methods for improving milk foam stability mainly rely on adding emulsifiers or thickeners (such as monoglycerides, sucrose esters, carrageenan, etc.) to increase the system viscosity and delay liquid film drainage. However, these methods often only provide physical stabilization and cannot fundamentally improve the foaming properties of milk proteins. Furthermore, the excessive use of some chemical emulsifiers poses potential health risks and contradicts the current consumer trend towards "clean labels."

[0004] In recent years, enzymatic modification of milk proteins has become a research hotspot. Transglutaminase (TG enzyme) has been used to improve the gel properties and thermal stability of dairy products. However, although the network structure formed by TG enzyme through cross-linking can improve the stability of the system, its effect on the flexibility of the protein interface and its application in foaming properties still have certain limitations.

[0005] Protein glutaminase (PG enzyme) is an enzyme that specifically catalyzes the deamidation of glutamine residues in proteins, converting glutamine into glutamate, thereby increasing the net negative charge and solubility of the protein molecule. Studies have shown that PG enzymes can significantly improve the emulsifying and foaming properties of plant proteins. However, research on the application of PG enzymes in liquid milk systems to improve milk foam stability is currently lacking, particularly regarding technical solutions that combine them with specific stabilizers to synergistically improve milk foam performance. Summary of the Invention

[0006] To address the problems of poor foam stability and easy defoaming in existing liquid dairy products, this invention aims to provide a foaming agent composition that can effectively improve the foaming properties and / or foam stability of liquid dairy products, as well as a method for preparing liquid dairy products using this composition and improving their foaming properties and / or foam stability. This foaming agent composition involves the directional modification of milk proteins by protein glutaminase and synergistic effects with other auxiliary stabilizers in the composition, significantly improving the foam stability of liquid dairy products during foaming.

[0007] This invention is achieved through the following technical solution:

[0008] 1. A foaming agent composition for use in liquid dairy products, wherein the foaming agent composition comprises or consists of the following components by weight percentage:

[0009] (a) 1-40% protein glutaminase;

[0010] (b) 30-80% of substances selected from the group consisting of glucon gum and β-glucan, with glucon gum being preferred;

[0011] (c) 1-20% of substances selected from the following group: maltodextrin, cellulose derivatives and sodium polyacrylate;

[0012] (d) 0.3-10% chloride.

[0013] 2. The foaming agent composition according to claim 1, wherein the foaming agent composition comprises or consists of the following components by weight percentage:

[0014] (a) 1-40% protein glutaminase;

[0015] (b) 30-70% of substances selected from the following group: glucan gum and β-glucan;

[0016] (c) 1-18% of substances selected from the following group: maltodextrin, cellulose derivatives and sodium polyacrylate;

[0017] (d) 0.1-4% calcium chloride;

[0018] (e) 0.1-4% magnesium chloride; and

[0019] (f) 0.1-4% sodium chloride.

[0020] 3. The foaming agent composition according to claim 1 or 2, wherein the foaming agent composition comprises or consists of the following components by weight percentage:

[0021] (a) 8-35% protein glutaminase;

[0022] (b) 38-65% of substances selected from the following group: glucon and β-glucan;

[0023] (c) 1-18% of substances selected from the following group: maltodextrin, cellulose derivatives and sodium polyacrylate;

[0024] (d) 0.1-3% calcium chloride;

[0025] (e) 0.1-3% magnesium chloride; and

[0026] (f) 0.1-3% sodium chloride.

[0027] 4. The foaming agent composition according to any one of items 1-3, wherein the protein glutaminase is obtained from the following sources: microbial fermentation, plant extraction, animal extraction; preferably obtained by fermentation of a microbial strain capable of expressing protein glutaminase and extraction of the corresponding enzyme from the fermentation broth.

[0028] 5. The foaming agent composition according to any one of items 1-4, wherein the specific enzyme activity of the protein glutaminase is 20 U / g or more, preferably 50 U / g or more, and more preferably 100 U / g or more.

[0029] 6. The foaming agent composition according to any one of claims 1-5, wherein the β-glucan is selected from the group consisting of fungal β-glucan, cereal β-glucan, bacterial β-glucan and algal β-glucan, preferably the β-glucan is selected from the group consisting of yeast β-glucan, oat β-glucan, barley β-glucan, wheat β-glucan and Bacillus β-glucan.

[0030] 7. The foaming agent composition according to any one of items 1-6, used to improve the foaming properties and / or foam stability of liquid dairy products, preferably the liquid dairy products selected from the group consisting of raw cow milk, raw goat milk, and reconstituted emulsions obtained by adding water to whole milk powder and / or skim milk powder.

[0031] 8. A method for preparing a foaming agent composition according to any one of claims 1-7, comprising mixing the components in the stated mass percentages to prepare the foaming agent composition.

[0032] 9. Use of the foaming agent composition according to any one of items 1-7 for preparing dairy products with high foam stability or for improving the foaming properties and / or foam stability of liquid dairy products.

[0033] 10. A dairy product ingredient composition comprising or consisting of the following components:

[0034] Raw milk;

[0035] The foaming agent composition of any one of items 1-7 or the foaming agent composition prepared according to the method of item 8.

[0036] 11. The composition according to claim 10, wherein the composition comprises or consists of the following components by weight percentage:

[0037] (1) 90-99% raw milk;

[0038] (2) 0.01-1.5% of the foaming agent composition according to any one of items 1-7 or the foaming agent composition prepared according to the method described in item 8; and

[0039] (3) 0-9.5% of other excipients.

[0040] 12. The composition according to item 10 or 11, wherein the protein content of the raw milk is not less than 1%, preferably not less than 2.8%, more preferably not less than 4%.

[0041] 13. The composition according to any one of items 10-12, wherein the raw milk is selected from the group consisting of raw cow's milk, raw goat's milk and reconstituted milk powder with water, preferably the milk powder being whole milk powder and / or skim milk powder.

[0042] 14. A method for preparing dairy products, comprising the following steps:

[0043] (1) Ingredients, comprising adding the foaming agent composition of any one of items 1-7 to the raw milk to obtain a mixture;

[0044] (2) Incubation and homogenization, comprising homogenizing the mixture after maintaining it at 4-65°C for 0.5-24 hours; and

[0045] (3) Sterilization, which includes pasteurizing or UHT sterilizing the homogenized liquid and then cooling it to obtain the dairy product.

[0046] 15. The method according to item 14, comprising the following steps:

[0047] (1) Ingredients, comprising mixing the foaming agent composition of any one of items 1-7 with a portion of the raw milk and mixing it evenly, then adding it to the remaining raw milk and mixing it evenly again to obtain a mixture;

[0048] (2) Incubation and homogenization, comprising maintaining the mixture at 40-65°C for 0.5-3 hours followed by homogenization; and

[0049] (3) Sterilization, which includes sterilizing the homogenized liquid at 90-115°C for 5-20 minutes and then cooling it to obtain the dairy product.

[0050] 16. The method according to item 14 or 15, wherein the homogenization in step (1) is carried out under the following conditions: a first-stage pressure of 150-200 Bar, a second-stage pressure of 30-40 Bar, a homogenization temperature of 50-60°C, and 1-3 homogenization cycles.

[0051] 17. The method according to any one of items 14-16, wherein step (3) further includes the steps of packaging and / or refrigerating the resulting dairy products.

[0052] 18. A dairy product prepared by any one of items 14-17.

[0053] 19. The method according to any one of items 14-17 or the dairy product according to item 18, wherein the dairy product is compared with a control dairy product prepared using a raw material composition that does not contain the foaming agent composition according to any one of items 1-7:

[0054] (1) The foam retention rate of the dairy product after 30 minutes is at least 40%, preferably at least 60%, and more preferably at least 85%; while the foam retention rate of the control dairy product after 30 minutes is no more than 20%.

[0055] (2) The 60-minute foam retention rate of the dairy product is at least 40%, preferably at least 60%, more preferably at least 85%; while the 60-minute foam retention rate of the control dairy product is 0; and / or

[0056] (3) The milk foam taste score increases by at least 20%, preferably at least 50%, and more preferably at least 70%.

[0057] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments. Detailed Implementation

[0058] 1. The foaming agent composition of the present invention

[0059] In one aspect, a foaming agent composition for use in dairy products is provided. In one embodiment, the foaming agent composition is used in liquid dairy products. In one embodiment, the foaming agent composition comprises or consists of the following components: (a) protein glutaminase; (b) auxiliary stabilizer 1; (c) auxiliary stabilizer 2; and (d) chloride. In one embodiment, the auxiliary stabilizer 1 is a functional polysaccharide food colloid. In one embodiment, the auxiliary stabilizer 1 is selected from the group consisting of gellan gum and β-glucan. In one embodiment, the auxiliary stabilizer 1 is gellan gum. In one embodiment, the auxiliary stabilizer 2 is a food water-soluble polymeric thickener and stabilizer. In one embodiment, the auxiliary stabilizer 2 is selected from the group consisting of maltodextrin, cellulose derivatives, and sodium polyacrylate. In one embodiment, the auxiliary stabilizer 2 is maltodextrin. In one embodiment, the chloride is selected from the group consisting of calcium chloride, magnesium chloride, and sodium chloride.

[0060] In one embodiment, the foaming agent composition comprises, or consists of, the following components by weight percentage: (a) 1-40% protein glutaminase; (b) 30-80% of a substance selected from the group consisting of gellan gum and β-glucan, preferably gellan gum; (c) 1-20% of a substance selected from the group consisting of maltodextrin, cellulose derivatives, and sodium polyacrylate; and (d) 0.3-10% chloride. In another embodiment, the foaming agent composition comprises, or consists of, the following components by weight percentage: (a) 1-40% protein glutaminase; (b) 30-70% of a substance selected from the group consisting of gellan gum and β-glucan; (c) 1-18% of a substance selected from the group consisting of maltodextrin, cellulose derivatives, and sodium polyacrylate; (d) 0.1-4% calcium chloride; (e) 0.1-4% magnesium chloride; and (f) 0.1-4% sodium chloride. In one embodiment, the foaming agent composition comprises, or consists of, the following components by weight percentage: (a) 8-35% protein glutaminase; (b) 38-65% of substances selected from the group consisting of gluconol and β-glucan; (c) 1-18% of substances selected from the group consisting of maltodextrin, cellulose derivatives, and sodium polyacrylate; (d) 0.1-3% calcium chloride; (e) 0.1-3% magnesium chloride; and (f) 0.1-3% sodium chloride.

[0061] In one embodiment, the foaming agent composition comprises, by weight percentage, 1-40%, 2-40%, 5-40%, 10-40%, 15-40%, 20-40%, 25-40%, 30-40%, 35-40%, 1-35%, 2-35%, 5-35%, 10-35%, 15-35%, 20-35%, 25-35%, 30-35%, 1-30%, 2-30%, 5-30%, 10-3 Protein glutaminases at concentrations of 0%, 15-30%, 20-30%, 25-30%, 1-25%, 2-25%, 5-25%, 10-25%, 15-25%, 20-25%, 1-20%, 2-20%, 5-20%, 10-20%, 15-20%, 1-15%, 2-15%, 5-15%, 10-15%, 1-10%, 2-10%, 5-10%, 1-5%, 2-5%, or 1-2%. The protein glutaminase of this invention optimizes the interfacial behavior of proteins through specific deamidation. It precisely targets the glutamine residues of proteins, converting them into glutamate, thereby altering the protein's charge and surface activity, making its adsorption at the gas-liquid interface more efficient, reducing surface tension, and ultimately enhancing foaming ability and stabilizing foam structure. The protein glutaminase of this invention acts only on glutamine residues, avoiding non-specific modification; it meets food safety standards and is a legal and compliant enzyme preparation for use in the food industry; and it is operated under mild conditions to minimize negative impacts on flavor, texture, and nutrition.

[0062] In one embodiment, the foaming agent composition comprises, by weight percentage, 30%-80%, 35%-80%, 40%-80%, 45%-80%, 50%-80%, 55%-80%, 60%-80%, 65%-80%, 70%-80%, 75%-80%, 30%-75%, 35%-75%, 40%-75%, 45%-75%, 50%-75%, 55%-75%, 60%-75%, 65%-75%, 70%-75%, 30%-70%, 35%-70%, 40%-70%, 45%-70%, 50%-70%, 55%-70%, 60%-70%, 65%-70%. Substances selected from the group consisting of 30%-65%, 35%-65%, 40%-65%, 45%-65%, 50%-65%, 55%-65%, 60%-65%, 30%-60%, 35%-60%, 40%-60%, 45%-60%, 50%-60%, 55%-60%, 30%-55%, 35%-55%, 40%-55%, 45%-55%, 50%-55%, 30%-50%, 35%-50%, 40%-50%, 45%-50%, 30%-45%, 35%-45%, 40%-45%, 30%-40%, 35%-40%, or 30%-35% of the following: glucon gum and β-glucan. In one embodiment, the β-glucan is selected from the group consisting of fungal β-glucan, cereal β-glucan, bacterial β-glucan, and algal β-glucan. In another embodiment, the β-glucan is selected from the group consisting of yeast β-glucan, oat β-glucan, barley β-glucan, wheat β-glucan, and Bacillus β-glucan. The curdlan of the present invention can form a rigid three-dimensional network structure that can physically encapsulate air bubbles, significantly increasing the elastic modulus (G') of the continuous liquid phase, inhibiting the coalescence, rise, and rupture of milk foam, and possessing high mechanical strength, freeze resistance, and thermal stability. It performs excellently in high-temperature processed dairy products (such as pasteurization) and can maintain the structural integrity of milk foam for a long time. The glucan of the present invention forms a highly viscoelastic gel phase in water, significantly increasing the viscosity of the continuous phase and slowing down the bubble migration rate. The molecular chains can be partially adsorbed onto the bubble interface, synergistically forming a protein-polysaccharide complex membrane with milk proteins (such as casein), enhancing the toughness and rupture resistance of the interfacial membrane. The guar gum and / or β-glucan of this invention can synergistically interact with protein glutaminase to form a "protein-polysaccharide complex stable system," balancing interfacial membrane strength and continuous phase rheological regulation.

[0063] In one embodiment, the foaming agent composition comprises, by weight percentage, 1-20%, 2-20%, 5-20%, 8-20%, 10-20%, 12-20%, 15-20%, 18-20%, 1-15%, 2-15%, 5-15%, 8-15%, 10-15%, 12-15%, 1-12%, 2-12%, 5-12%, 8-12%, 10-12%, 1-10%, 2-10%, 5-10%, 8-10%, 1-8%, 2-8%, 5-8%, 1-5%, 2-5%, or 1-2% of a substance selected from the group consisting of maltodextrin, cellulose derivatives, and sodium polyacrylate. The main function of the maltodextrin of this invention is to increase the viscosity of the liquid phase and slow down the rate of bubble rise and coalescence. It indirectly stabilizes the gas-liquid interface by forming a physical barrier, inhibiting foam breakage. It does not possess significant surface activity and does not directly adsorb onto the bubble surface; instead, it achieves foam stabilization by improving the rheological properties of the continuous phase. The maltodextrin of this invention can also simultaneously enhance the overall structural uniformity of the system. The cellulose derivative of this invention can form a three-dimensional network structure, significantly improving the elastic modulus (G') and viscosity of the system. Its hydrophilic groups can partially adsorb onto the bubble interface, forming a mechanically strong interfacial film that resists external disturbances. This network structure can "capture" bubbles, limiting their migration and coalescence, thereby extending the life of the milk foam. The sodium polyacrylate of this invention is a strongly anionic synthetic polymer with an aqueous solution viscosity far exceeding that of natural colloids, forming a highly viscoelastic gel phase. It also stabilizes negatively charged bubbles and droplets through electrostatic repulsion, preventing coalescence. The maltodextrin, cellulose derivatives and / or sodium polyacrylate of the present invention can synergistically interact with protein glutaminase, and further interact synergistically with gellan gum and / or β-glucan, enriching the connotation of the "protein-polysaccharide complex stable system", broadening the process adaptability and optimizing the taste experience of milk foam.

[0064] In one embodiment, the foaming agent composition comprises 0.3-10% chloride by weight percentage. In another embodiment, the foaming agent composition comprises, by weight percentage: 0.3-10%, 0.5-10%, 0.8-10%, 1-10%, 2-10%, 3-10%, 4-10%, 5-10%, 6-10%, 7-10%, 8-10%, 9-10%, 0.3-9%, 0.5-9%, 0.8-9%, 1-9%, 2-9%, 3-9%, 4-9%, 5-9%, 6-9%, 7-9%, 8-9%, 0.3-8%, 0.5-8%, 0.8-8%, 1-8%, 2-8%, 3-8%, 4-8%, 5-8%, 6-8%, 7-8%, 0.3-7%, 0.5-7%, 0.8-7%, 1-7%, 2-7%. Chlorides of 3-7%, 4-7%, 5-7%, 6-7%, 0.3-6%, 0.5-6%, 0.8-6%, 1-6%, 2-6%, 3-6%, 4-6%, 5-6%, 0.3-5%, 0.5-5%, 0.8-5%, 1-5%, 2-5%, 3-5%, 4-5%, 0.3-4%, 0.5-4%, 0.8-4%, 1-4%, 2-4%, 3-4%, 0.3-3%, 0.5-3%, 0.8-3%, 1-3%, 2-3%, 0.3-2%, 0.5-2%, 0.8-2%, 1-2%, 0.3-1%, 0.5-1%, 0.8-1%, 0.3-0.8%, 0.5-0.8%, and 0.3-0.5%. In one embodiment, the chloride is selected from the group consisting of calcium chloride, magnesium chloride, sodium chloride, and potassium chloride. In one embodiment, the foaming agent composition comprises, by weight percentage, 0.1-4% calcium chloride, 0.1-4% magnesium chloride, and 0.1-4% sodium chloride. The Ca²⁺ in the calcium chloride of this invention has a high charge density, which can specifically bind to phosphoserine residues in casein microparticles, inducing microparticle structural rearrangement and promoting cross-linking between protein molecules. At the bubble interface, Ca²⁺ enhances the surface adsorption density of proteins, forming a dense, low-flow, and highly elastic interfacial film, significantly inhibiting bubble coalescence and liquid film drainage, and increasing the half-life of milk foam. The Mg²⁺ in the magnesium chloride of this invention promotes the migration of more protein molecules to the bubble interface, increasing the interfacial adsorption amount, thereby enhancing the mechanical strength of the film and extending the foam life. The Na⁺ in the sodium chloride of this invention mainly promotes protein adsorption at the interface by slightly reducing the electrostatic repulsion of the system, representing the mildest ionic intervention method.

[0065] In one embodiment, the protein glutaminase (PG enzyme) is obtained from microbial fermentation, plant extraction, or animal extraction. In another embodiment, the protein glutaminase (PG enzyme) is obtained by fermentation of a microbial strain capable of expressing the corresponding enzyme and extraction of the corresponding enzyme from the fermentation broth.

[0066] In one embodiment, the specific enzyme activity of the protein glutaminase (PG enzyme) is ≥20 U / g, ≥25 U / g, ≥30 U / g, ≥35 U / g, ≥40 U / g, ≥45 U / g, ≥50 U / g, ≥55 U / g, ≥60 U / g, ≥65 U / g, ≥70 U / g, ≥75 U / g, ≥80 U / g, ≥85 U / g, ≥90 U / g, ≥95 U / g, or ≥100 U / g. In one embodiment, the protein glutaminase (PG enzyme) is commercially available. In one embodiment, the protein glutaminase (PG enzyme) is derived from Taixing Dongsheng Biotechnology Co., Ltd.

[0067] In one embodiment, the foaming agent composition is used to improve the foaming properties and / or foam stability of the liquid dairy product. In one embodiment, the foaming agent composition is used to improve the foam stability of the liquid dairy product. In one embodiment, the liquid dairy product is selected from the group consisting of raw cow's milk, raw goat's milk, and reconstituted emulsions obtained by adding water to whole milk powder and / or skim milk powder.

[0068] 2. A method for producing the foaming agent composition of the present invention.

[0069] In one aspect, a method for preparing the foaming agent composition of the present invention is provided, comprising mixing the components in the stated mass percentages to prepare the foaming agent composition. In one embodiment, the method comprises uniformly mixing the components in the stated mass percentages to prepare the foaming agent composition.

[0070] 3. Uses of the foaming agent composition of the present invention

[0071] In one aspect, the use of the foaming agent composition of the present invention in the preparation of dairy products is provided. In one embodiment, the dairy product is a liquid dairy product. In one embodiment, the liquid dairy product is selected from the group consisting of raw cow's milk, raw goat's milk, and reconstituted emulsions obtained by adding water to whole milk powder and / or skim milk powder. In one aspect, the use of the foaming agent composition of the present invention in improving the foaming properties and / or foam stability of liquid dairy products is provided. In one aspect, the use of the foaming agent composition of the present invention in improving the foam stability of liquid dairy products is provided.

[0072] 4. The dairy raw material composition of the present invention

[0073] The present invention also provides a dairy product raw material composition comprising or consisting of raw milk and the foaming agent composition of the present invention. In one embodiment, the raw material composition comprises or consists of raw milk and a foaming agent composition prepared according to the method of the present invention. In one embodiment, the raw material composition comprises or consists of the following components by mass percentage: (1) 90-99% raw milk; (2) 0.01-1.5% foaming agent composition of the present invention; and (3) 0-9.5% other excipients.

[0074] In one embodiment, the raw material composition comprises, by weight percentage, 90-99%, 92-99%, 95-99%, 98-99%, 90-98%, 92-98%, 95-98%, 90-95%, 92-95%, or 90-92% raw milk. In one embodiment, the raw milk is selected from the group consisting of raw cow's milk, raw goat's milk, and reconstituted milk powder with water. In one embodiment, the milk powder is whole milk powder and / or skim milk powder. In one embodiment, the protein content of the raw milk is not less than 1%, not less than 1.2%, not less than 1.5%, not less than 1.8%, not less than 2%, not less than 2.2%, not less than 2.5%, not less than 2.8%, not less than 3%, not less than 3.2%, not less than 3.5%, not less than 3.8%, or not less than 4%.

[0075] In one embodiment, the raw material composition comprises, by weight percentage: 0.01-1.5%, 0.02-1.5%, 0.05-1.5%, 0.08-1.5%, 0.1-1.5%, 0.12-1.5%, 0.15-1.5%, 0.18-1.5%, 0.2-1.5%, 0.5-1.5%, 0.8-1.5%, 1.0-1.5%, 1.2-1.5%, 0.01-1.2%, 0.02-1.2%, 0.05-1.2%, 0.08-1.2%, 0.1-1.2%, 0.12-1.2%, 0.15-1.2%, 0.18-1.2%, 0.2-1.2%. 0.5-1.2%, 0.8-1.2%, 1.0-1.2%, 0.01-1.0%, 0.02-1.0%, 0.05-1.0%, 0.08-1.0%, 0.1-1.0%, 0.12-1.0%, 0.15-1.0%, 0.18-1.0%, 0.2-1.0%, 0.5-1.0%, 0.8-1.0%, 0.01-0.8%, 0.02-0.8%, 0.05-0.8%, 0.08-0.8%, 0.1-0.8%, 0.12-0.8%, 0.15-0.8%, 0.18-0.8%, 0.2-0.8%, 0.5-0.8%, 0.01-0.5 %, 0.02-0.5%, 0.05-0.5%, 0.08-0.5%, 0.1-0.5%, 0.12-0.5%, 0.15-0.5%, 0.18-0.5%, 0.2-0.5%, 0.01-0.2%, 0.02-0.2%, 0.05-0.2%, 0.08-0.2%, 0.1-0.2%, 0.12-0.2%, 0.15-0.2%, 0.18-0.2%, 0.01-0.18%, 0.02-0.18%, 0.05-0.18%, 0.08-0.18%, 0.1-0.18%, 0.12-0.18%, 0.15-0.18%, 0. The foaming agent compositions of the present invention are 0.1-0.15%, 0.02-0.15%, 0.05-0.15%, 0.08-0.15%, 0.1-0.15%, 0.12-0.15%, 0.01-0.12%, 0.02-0.12%, 0.05-0.12%, 0.08-0.12%, 0.1-0.12%, 0.01-0.10%, 0.02-0.10%, 0.05-0.10%, 0.08-0.10%, 0.01-0.08%, 0.02-0.08%, 0.05-0.08%, 0.01-0.05%, 0.02-0.05%, or 0.01-0.02%.

[0076] In one embodiment, the raw material composition comprises, by weight percentage, 0-9.5%, 1-9.5%, 2-9.5%, 3-9.5%, 4-9.5%, 5-9.5%, 6-9.5%, 7-9.5%, 8-9.5%, 9-9.5%, 0-9%, 1-9%, 2-9%, 3-9%, 4-9%, 5-9%, 6-9%, 7-9%, 8-9%, 0-8%, 1-8%, 2-8%, 3-8%, 4- Other excipients comprising 8%, 5-8%, 6-8%, 7-8%, 0-7%, 1-7%, 2-7%, 3-7%, 4-7%, 5-7%, 6-7%, 0-6%, 1-6%, 2-6%, 3-6%, 4-6%, 5-6%, 0-5%, 1-5%, 2-5%, 3-5%, 4-5%, 0-4%, 1-4%, 2-4%, 3-4%, 0-3%, 1-3%, 2-3%, 0-2%, 1-2%, or 0-1%. In one embodiment, the excipients are selected from the group consisting of flavoring agents, preservatives, coloring agents, and spices. In one embodiment, the flavoring agent is selected from the group consisting of granulated sugar, caster sugar, glucose, sucrose, and sugar-free sweeteners. In one embodiment, the preservative is selected from the group consisting of benzoic acid or a salt thereof, sorbic acid or a salt thereof, nisin, dehydroacetic acid or a salt thereof. In one embodiment, the colorant is selected from the group consisting of: natural colorants (including but not limited to β-carotene, red yeast rice, radish red, turmeric), caramel color, titanium dioxide, carmine, sunset yellow, tartrazine, and red yeast rice. In one embodiment, the flavoring is selected from the group consisting of: vanilla flavorings, fruit flavorings (including but not limited to strawberry, chocolate, lemon, and orange), and compound flavorings.

[0077] In one embodiment, the raw material composition is used to produce a liquid dairy product. In another embodiment, the raw material composition is used to produce a liquid dairy product with high foaming properties and / or high foam stability.

[0078] 5. Methods for preparing dairy products

[0079] In one aspect, a method for preparing dairy products is provided, comprising the steps of: (1) ingredient preparation; (2) heat preservation and homogenization; and (3) sterilization.

[0080] In one embodiment, step (1) includes: providing each component of the dairy raw material composition of the present invention, and adding the foaming agent composition of the present invention to the raw milk to obtain a mixture. In one embodiment, step (1) includes providing the foaming agent composition of the present invention and raw milk, adding the foaming agent composition to the raw milk and mixing evenly to obtain a mixture. In one embodiment, step (1) includes providing the foaming agent composition of the present invention and raw milk, adding the foaming agent composition to a portion of the raw milk and mixing evenly, then adding it to the remaining raw milk and mixing evenly again to obtain a mixture.

[0081] In one embodiment, step (2) includes homogenizing the mixture after maintaining it at 4-65°C for 0.5-24 hours. In one embodiment, step (2) includes: subjecting the mixture to temperatures of 4-65°C, 5-65°C, 10-65°C, 15-65°C, 20-65°C, 25-65°C, 30-65°C, 35-65°C, 40-65°C, 45-65°C, 50-65°C, 55-65°C, 60-65°C, 4-60°C, 5-60°C, 10-60°C, 15-60°C, 20-60°C, 25-60°C, 30-60°C, 35-60°C, 40-60°C, 45-60°C, 50-60°C, 55-60°C, 4-55°C, 5-55°C, 10-55°C, 15-55°C, 20-55°C, 25-55°C, 3 0-55℃, 35-55℃, 40-55℃, 45-55℃, 50-55℃, 4-50℃, 5-50℃, 10-50℃, 15-50℃, 20-50℃, 25-50℃, 30-50℃, 35-50℃, 40-50℃, 45-50℃, 4-45℃, 5-45℃, 10-45℃, 15-45℃, 20-45℃, 25-45℃, 30-45℃, 35-45℃, 40-45℃, 4-40℃, 5-40℃, 10-40℃, 15-40℃, 20-40℃, 25-40℃, 30-40℃, 35-40℃, 4-35℃, 5-35℃, 10-35℃, 15- Maintain at temperatures of 35℃, 20-35℃, 25-35℃, 30-35℃, 4-30℃, 5-30℃, 10-30℃, 15-30℃, 20-30℃, 25-30℃, 4-25℃, 5-25℃, 10-25℃, 15-25℃, 20-25℃, 4-20℃, 5-20℃, 10-20℃, 15-20℃, 4-15℃, 5-15℃, 10-15℃, 4-10℃, 5-10℃, or 4-5℃ for 0.5-24, 1-24, 2-24, 4-24, 6-24, 8-24, 10-24, 12-24, 14-24, 16-24, 18-24, 20-24, or 22-24. 0.5-22, 1-22, 2-22, 4-22, 6-22, 8-22, 10-22, 12-22, 14-22, 16-22, 18-22, 20-22, 0.5-20, 1-20, 2-20, 4-20, 6-20, 8-20, 10-20, 12-20, 14-20, 16-20, 18-20, 0.5-18, 1-18, 2-18, 4-18, 6-18, 8-18, 10-18, 12-18, 14-18, 16-18, 0.5-16, 1-16, 2-16, 4-16, 6-16, 8-16, 10-16, 12-16, 14-16, 0.5-14, 1-14, 2-14, 4-14, 6-14, 8-14, 10-14, 12-14, 0.5-12, 1-12, 2-12, 4-12, 6-12, 8-12, 10-12, 0.5-10, 1-10, 2-10, 4-10, 6-10, 8-10, 0.5-8, 1-8, 2-8, 4-8, 6-8, 0.5-6, 1-6, 2-6, 4-6, 0.5-4, 1-4, 2-4, 0.5-2, 1-2 or 0.5-1 hour.

[0082] In one embodiment, the homogenization is performed in a homogenizer. In one embodiment, the homogenizer is selected from the group consisting of: high-pressure homogenizers, fully automatic homogenizers, mechanical hammer homogenizers, high-shear homogenizers, and microjet homogenizers. In one embodiment, the homogenization process includes performing two-stage homogenization. In one embodiment, the pressure of the first-stage homogenization is 150-200 Bar, 160-200 Bar, 170-200 Bar, 180-200 Bar, 190-200 Bar, 150-190 Bar, 160-190 Bar, 170-190 Bar, 180-190 Bar, 150-180 Bar, 160-180 Bar, 170-180 Bar, 150-170 Bar, 160-170 Bar, and 150-160 Bar. In one embodiment, the pressure of the secondary homogenization is 30-50 Bar, 35-50 Bar, 40-50 Bar, 45-50 Bar, 30-45 Bar, 35-45 Bar, 40-45 Bar, 30-40 Bar, 35-40 Bar, or 30-35 Bar. In one embodiment, the homogenization process is performed at the following temperatures: 50-65°C, 52-65°C, 55-65°C, 58-65°C, 60-65°C, 62-65°C, 50-62°C, 52-62°C, 55-62°C, 58-62°C, 60-62°C, 50-60°C, 52-60°C, 55-60°C, 58-60°C, 50-55°C, 52-55°C, or 50-52°C. In one embodiment, the homogenization is performed 1-3 times. In one implementation, the homogenization is performed once, twice, or three times.

[0083] In one embodiment, the sterilization step includes pasteurizing or ultra-high temperature (UHT) sterilization of the homogenized liquid, followed by cooling to obtain the dairy product. In one embodiment, the sterilization process kills harmful microorganisms in the dairy product while preserving as much of its nutritional components, flavor, and texture as possible. In one embodiment, the sterilization step includes sterilizing the homogenized liquid at temperatures of 90-115°C, 92-115°C, 95-115°C, 98-115°C, 100-115°C, 102-115°C, 105-115°C, 108-115°C, 110-115°C, 112-115°C, 90-112°C, 92-112°C, 95-112°C, 98-112°C, and 100-115°C. 2℃, 102-112℃, 105-112℃, 108-112℃, 110-112℃, 90-110℃, 92-110℃, 95-110℃, 98-110℃, 100-110℃, 102-110℃, 105-110℃, 108-110℃, 90-108℃, 92-108℃, 95-108℃, 98-108℃, 100-108℃, 10 2-108℃, 105-108℃, 90-105℃, 92-105℃, 95-105℃, 98-105℃, 100-105℃, 102-105℃, 90-102℃, 92-102℃, 95-102℃, 98-102℃, 100-102℃, 90-100℃, 92-100℃, 95-100℃, 98-100℃, 90-98℃, 92- Heat treatment at 98℃, 95-98℃, 90-95℃, 92-95℃, or 90-92℃ for 5-20, 8-20, 10-20, 12-20, 15-20, 18-20, 5-18, 8-18, 10-18, 12-18, 15-18, 5-15, 8-15, 10-15, 12-15, 5-12, 8-12, 10-12, 5-10, 8-10, or 5-8 minutes. In one embodiment, the cooling includes cooling the sterilized liquid to room temperature. In one embodiment, the cooling includes cooling the sterilized liquid to 4-25℃.

[0084] In one embodiment, the method for preparing the dairy product of the present invention further includes the steps of packaging and / or refrigerating the obtained dairy product. In one embodiment, the packaging step includes packaging at 0-4°C according to weight specifications. In one embodiment, the refrigeration step includes refrigerating the packaged dairy product at 0-4°C.

[0085] In one embodiment, the method is used to prepare a liquid dairy product. In one embodiment, the liquid dairy product is selected from the group consisting of raw cow's milk, raw goat's milk, and reconstituted emulsions obtained by adding water to whole milk powder and / or skim milk powder. In one embodiment, the method is used to improve the foaming properties and / or foam stability of the liquid dairy product. In one embodiment, the method is used to improve the foam stability of the liquid dairy product.

[0086] 6. The dairy products of the present invention

[0087] In one aspect, a dairy product produced using the method for preparing dairy products of the present invention is provided. In one embodiment, the dairy product is a liquid dairy product. In one embodiment, the liquid dairy product is selected from the group consisting of raw cow's milk, raw goat's milk, and reconstituted emulsions obtained by adding water to whole milk powder and / or skim milk powder. In one embodiment, the dairy product is a liquid dairy product in which foaming properties and / or foam stability are significantly improved. In one embodiment, the dairy product is a liquid dairy product in which foam stability is significantly improved.

[0088] In one embodiment, the dairy product of the present invention, compared with a control dairy product prepared using a raw material composition not containing the foaming agent composition of the present invention, has the following characteristics: (1) a 10-minute foam retention rate of at least 75%, at least 80%, at least 85%, at least 90%, or at least 92.8%, while the 10-minute foam retention rate of the control dairy product is no more than 65%, no more than 60%, no more than 55%, or no more than 50%; (2) a 30-minute foam retention rate of at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, or at least 85%, while the 30-minute foam retention rate of the control dairy product is no more than 20%, no more than 18%, or no more than 16%; (3) a 60-minute foam retention rate of at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, or at least 85%, while the 60-minute foam retention rate of the control dairy product is 0; and / or (3) The milk foam texture score increased by at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, or at least 70%.

[0089] 7. The technical problem solved and the beneficial effects of this invention.

[0090] The technical problem solved by this invention is to overcome the problems of poor foam stability and easy defoaming when frothing liquid milk. This invention provides a compound foaming agent composition that improves the stability of liquid milk foam and can be stably implemented in industrial production. The foaming agent composition of this invention mainly utilizes protein glutaminase (PG enzyme) to directionally modify the protein, increasing its negative charge and hydrophilicity. This causes the protein molecules to partially unfold, exposing more hydrophobic regions and enhancing their adsorption capacity at the gas-liquid interface. This allows the modified milk protein to be adsorbed onto the bubble surface more quickly, forming a dense viscoelastic film. Furthermore, the synergistic effect of auxiliary stabilizers 1 and 2 further locks in the bubbles through steric hindrance and viscosity effects, improving the stability of the milk foam. In addition, it simplifies labeling and has good production prospects.

[0091] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0092] (1) Significant synergistic effect: The combination of PG enzyme with auxiliary stabilizer 1 (functional polysaccharide food colloid) and / or auxiliary stabilizer 2 (food water-soluble polymer thickener and stabilizer) produced a synergistic effect of 1+1+1>>3. Although using PG enzyme alone can improve foaming properties, the improvement in foam persistence is limited; using one or both stabilizers alone can mainly increase viscosity, but the foam fineness and foam persistence are also insufficient. After the combination of the three, the half-life of milk foam is extended by more than several times;

[0093] (2) Advantages of clean labeling: As a biological enzyme preparation, PG enzyme does not need to be labeled as a food additive in the final product, which is in line with the development trend of clean labeling. The amount of auxiliary stabilizers used is much lower than that of traditional formulations, which can significantly reduce the dependence on chemical additives;

[0094] (3) Improved stability: The heat stability and acid resistance of milk protein modified by PG enzyme are improved. No flocculation and precipitation occur after high temperature sterilization, and the product has good shelf-life stability.

[0095] (4) Optimized taste and texture: The liquid milk foam prepared by this invention has a delicate and dense texture. After being mixed with coffee, the foam lasts for a long time and can form exquisite latte art patterns, significantly improving the consumer experience. Detailed Implementation

[0096] The present invention will be further described below with reference to specific embodiments, but these specific embodiments should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make various changes or modifications to these specific embodiments without departing from the scope of the technical solution of the present invention, and the changed and modified implementation schemes still fall within the protection scope of the present invention.

[0097] All chemicals or products used in the examples are commercially available.

[0098] Example 1. Foaming agent composition 1 of the present invention and dairy product I of the present invention.

[0099] This embodiment aims to provide a compound foaming agent composition for improving the foaming properties and / or foam stability of liquid milk, and a working embodiment of liquid milk prepared using the composition.

[0100] The method for preparing the foaming agent composition 1 of the present invention is as follows:

[0101] The product is obtained by mixing 25% protein glutaminase, 60% guar gum, 10% maltodextrin, 1% calcium chloride, 1% magnesium chloride, and 3% sodium chloride by weight percentage.

[0102] The method for preparing dairy product I using the foaming agent composition 1 of the present invention is as follows:

[0103] Weigh out fresh milk with a protein content of 3.2% and a mass percentage of 98%. While stirring, add 0.3% of foaming agent composition 1 and the remaining flavoring agent. Heat to 55°C and keep warm for 60 minutes. Then, perform two-stage homogenization in a fully automatic homogenizer. After homogenization, sterilize the milk at 90-95°C for 5-10 minutes and then cool to obtain liquid milk with high foam stability (dairy product I of the present invention).

[0104] A quantitative amount of dairy product I of the present invention was weighed into a beaker and whipped for 3 minutes. The foam height was measured at 10, 30, and 60 minutes after whipping. A larger foam height indicates better foam stability over time. The test results are shown in Table 1.

[0105] Comparative Example 1. Comparison of Dairy Products I

[0106] This comparative example 1 is basically the same as Example 1 above, except that foaming agent composition 1 is not added in this comparative example, and the other preparation process and control parameters are the same as in Example 1.

[0107] A quantitative amount of control dairy product I was weighed into a beaker and whipped for 3 minutes. The foam height was measured at 10, 30, and 60 minutes after whipping. The test results are shown in Table 1.

[0108] Example 2. Foaming agent composition 2 of the present invention and dairy product II of the present invention.

[0109] The method for preparing the foaming agent composition 2 of the present invention is as follows:

[0110] The product is obtained by mixing 10% protein glutaminase, 65% β-glucan, 10% maltodextrin, 8% hydroxypropyl cellulose, 2% calcium chloride, 2% magnesium chloride, and 3% sodium chloride by weight percentage.

[0111] The method for preparing dairy product II using the foaming agent composition 1 of the present invention is as follows:

[0112] Weigh out fresh milk with a protein content of 3.0% and a mass percentage of 95%. While stirring, add 0.1% of foaming agent composition 2 and the remaining flavoring agent. Heat to 60°C and keep warm for 90 minutes. Then, perform two-stage homogenization in a fully automatic homogenizer. After homogenization, sterilize the milk at 95-98°C for 5-8 minutes and then cool to obtain liquid milk with high foam stability (dairy product II of the present invention).

[0113] A quantitative amount of the dairy product II of this invention was weighed into a beaker and whipped for 3 minutes. The foam height was measured at 10, 30, and 60 minutes after whipping. A larger foam height indicates better foam stability over time. The test results are shown in Table 1.

[0114] Comparative Example 2. Comparative Dairy Products II

[0115] Comparative Example 2 is basically the same as Example 2 above, except that 0.08% by mass of protein glutaminase (PG enzyme) is used instead of foaming agent composition 1 in this comparative example. The other preparation process and control parameters are the same as in Example 2.

[0116] A quantitative amount of control dairy product II was weighed into a beaker and whipped for 3 minutes. The foam height was measured at 10, 30, and 60 minutes after whipping. The test results are shown in Table 1.

[0117] Example 3. Foaming agent composition 3 of the present invention and dairy product III of the present invention.

[0118] The method for preparing the foaming agent composition 3 of the present invention is as follows:

[0119] The product is obtained by mixing 35% protein glutaminase, 35% gellan gum, 15% β-glucan, 8% maltodextrin, 2% sodium polyacrylate, 1.5% calcium chloride, 1% magnesium chloride, and 2.5% sodium chloride by weight percentage.

[0120] The method for preparing dairy product III using the foaming agent composition 1 of the present invention is as follows:

[0121] Weigh out fresh milk with a protein content of 2.5% and a mass percentage of 93%. While stirring, add 1.0% of foaming agent composition 3 and the remaining flavoring agent. Heat to 65°C and keep warm for 75 minutes. Then, perform two-stage homogenization in a fully automatic homogenizer. After homogenization, sterilize the milk at 98-101°C for 2-3 minutes and then cool to obtain liquid milk with high foam stability (dairy product III of this invention).

[0122] A quantitative amount of dairy product III of this invention was weighed into a beaker and whipped for 3 minutes. The foam height was measured at 10, 30, and 60 minutes after whipping. A larger foam height indicates better foam stability over time. The test results are shown in Table 1.

[0123] Comparative Example 3. Comparison with Dairy Products III

[0124] Comparative Example 3 is basically the same as Example 3 above, except that 0.2% by mass of kerogen gum is used instead of foaming agent composition 3 in this comparative example. The other preparation process and control parameters are the same as in Example 3.

[0125] A quantitative amount of control dairy product III was weighed into a beaker and whipped for 3 minutes. The foam height was measured at 10, 30, and 60 minutes after whipping. The test results are shown in Table 1.

[0126] (I) Milk foam height test

[0127] The milk foam height test results of Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below.

[0128] Table 1. Foam height test results of the dairy product of the present invention and the comparative dairy product.

[0129]

[0130] *Auxiliary stabilizer 1 is a substance selected from guar gum and β-glucan;

[0131] **Auxiliary stabilizer 2 is a substance selected from maltodextrin, cellulose derivatives and sodium polyacrylate.

[0132] The foaming agent composition of the present invention is a key factor in improving foaming properties. As shown in Table 1, after whipping for 3 minutes, the foam height of Examples 1-3 at 0 minutes was 20.7%, 4.8%, and 10% higher than that of Comparative Examples 1-3, respectively, demonstrating a significant improvement in the foaming properties of liquid milk.

[0133] The foaming agent compositions of the present invention also exhibit excellent foam stability. As shown in Table 1, the foam retention rates of dairy products I-III in Examples 1-3 containing foaming agent compositions 1-3 were 92.9%, 93.8%, and 93.9% respectively after 10 minutes of whipping; in contrast, the corresponding figures for the comparative examples not containing the foaming agent compositions of the present invention were 48.3%, 64.5%, and 63.3%.

[0134] As the time increased to half an hour, the advantages of dairy products I-III containing foaming agent compositions 1-3 became increasingly apparent. In Examples 1-3, dairy products I-III containing foaming agent compositions 1-3 still maintained foam retention rates of 85.7%, 87.7%, and 89.4% after 30 minutes of whipping; in contrast, the figures for the comparative examples not containing the foaming agent compositions of this invention were 0%, 16.1%, and 20%, respectively.

[0135] Even after an extended time of up to one hour, the foaming agent composition of the present invention still exhibited excellent (over 85%) foam stability. Dairy products I-III containing foaming agent compositions 1-3 in Examples 1-3 showed impressive foam retention rates of 85.7%, 86.1%, and 86.4% respectively after 60 minutes of whipping; in contrast, these figures were all 0% in the comparative examples that did not contain the foaming agent composition of the present invention.

[0136] Furthermore, Table 1 demonstrates the significant synergistic effect between PG enzyme and auxiliary stabilizers. When protein glutaminase (Comparative Example 2) and curdlan gum (Comparative Example 3) are used alone, their improvement on foam stability is limited, with 30-minute retention rates of 16.1% and 20%, respectively, only slightly higher than Comparative Example 1 without any added substances. Their 60-minute retention rates are both 0, the same as Comparative Example 1. This indicates that while using PG enzyme alone can improve foaming properties, the improvement in foam durability is limited. Using auxiliary stabilizers alone mainly relies on viscosity thickening, resulting in insufficient foam fineness and foam durability. The foaming agent composition of the present invention significantly extends the half-life of milk foam due to the synergistic effect of the compound components.

[0137] (II) Sensory evaluation

[0138] A double-blind evaluation panel of 30 people was randomly selected (neither the testers nor the test subjects knew whether they were evaluating the comparative dairy product or the dairy product of the present invention). The panel scored the overall taste of the milk foam obtained after whipping different dairy products for 3 minutes (on a scale of 1-10). The scoring criteria were strictly in accordance with Table 2.

[0139] Table 2. Overall Taste Evaluation Table for Dairy Products

[0140]

[0141] The test results for Examples 1-3 and Comparative Examples 1-3 are shown in Table 3:

[0142] Table 3. Overall Taste Test Results

[0143]

[0144] As shown in Table 3:

[0145] (a) Compared with dairy products without the foaming agent composition 1 of the present invention (Example 1 and Comparative Example 1), the overall taste score increased by at least 71.2%; (b) Compared with dairy products with 0.08% PG enzyme added, the overall taste score increased by at least 22.5%; (c) Compared with dairy products with 0.2% gellan gum added, the overall taste score increased by at least 25.7%;

[0146] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to the above-disclosed technical content without departing from the scope of the present invention, and all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A foaming agent composition for use in liquid dairy products, wherein the foaming agent composition comprises or consists of the following components by weight percentage: (a) 1-40% protein glutaminase; (b) 30-80% of substances selected from the group consisting of glucon gum and β-glucan, with glucon gum being preferred; (c) 1-20% of substances selected from the following group: maltodextrin, cellulose derivatives and sodium polyacrylate; (d) 0.3-10% chloride.

2. The foaming agent composition according to claim 1, wherein the foaming agent composition comprises or is composed of the following components by weight percentage: (a) 1-40% protein glutaminase; (b) 30-70% of substances selected from the following group: glucan gum and β-glucan; (c) 1-18% of substances selected from the following group: maltodextrin, cellulose derivatives and sodium polyacrylate; (d) 0.1-4% calcium chloride; (e) 0.1-4% magnesium chloride; and (f) 0.1-4% sodium chloride.

3. The foaming agent composition according to claim 1 or 2, wherein the foaming agent composition comprises or is composed of the following components by weight percentage: (a) 8-35% protein glutaminase; (b) 38-65% of substances selected from the following group: glucon and β-glucan; (c) 1-18% of substances selected from the following group: maltodextrin, cellulose derivatives and sodium polyacrylate; (d) 0.1-3% calcium chloride; (e) 0.1-3% magnesium chloride; and (f) 0.1-3% sodium chloride.

4. The foaming agent composition according to any one of claims 1-3, wherein the protein glutaminase is obtained from the following sources: microbial fermentation, plant extraction, animal extraction; preferably obtained by fermentation of a microbial strain capable of expressing protein glutaminase and extraction of the corresponding enzyme from the fermentation broth.

5. The foaming agent composition according to any one of claims 1-4, wherein the specific enzyme activity of the protein glutaminase is 20 U / g or more, preferably 50 U / g or more, and more preferably 100 U / g or more.

6. The foaming agent composition according to any one of claims 1-5, wherein the β-glucan is selected from the group consisting of fungal β-glucan, cereal β-glucan, bacterial β-glucan and algal β-glucan, preferably the β-glucan is selected from the group consisting of yeast β-glucan, oat β-glucan, barley β-glucan, wheat β-glucan and Bacillus β-glucan.

7. The foaming agent composition according to any one of claims 1-6, used to improve the foaming properties and / or foam stability of liquid dairy products, preferably the liquid dairy products are selected from the group consisting of: raw cow milk, raw goat milk and reconstituted emulsions obtained by adding water to whole milk powder and / or skim milk powder.

8. A method for preparing a foaming agent composition according to any one of claims 1-7, comprising mixing the components in the stated mass percentages to prepare the foaming agent composition.

9. The use of the foaming agent composition according to any one of claims 1-7 in the preparation of dairy products with high foam stability or in improving the foaming properties and / or foam stability of liquid dairy products.

10. A dairy product ingredient composition comprising or consisting of the following components: Raw milk; The foaming agent composition according to any one of claims 1-7 or the foaming agent composition prepared according to the method of claim 8.

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