Preparation method and application of soy protein emulsion gel for low-cholesterol egg tart

Abstract

The application discloses a preparation method and application of a low-cholesterol egg tart soybean protein emulsion gel, and relates to the technical field of food processing, in particular to a preparation method and application of a low-cholesterol egg tart soybean protein emulsion gel. The preparation method comprises the following steps: mixing a soybean protein isolate solution with a mass fraction of 2%-6% and vegetable fat according to a mass ratio of 15:1 to 8:1, and homogenizing the mixture under a pressure of 60 DEG C and 15-25 MPa to obtain an emulsion; adding a coagulating agent (such as calcium sulfate, TG enzyme and the like), and heating the emulsion at 180-200 DEG C for 18-25 minutes to form an emulsion gel. The gel (50-80 parts) is mixed with egg liquid (0-25 parts), syrup, sugar, an emulsifier (such as monoglyceride, Span 60 and the like), and a thickening agent (such as carrageenan, xanthan gum and the like) to prepare an egg tart liquid, the egg tart liquid is injected into an egg tart crust, and the egg tart is baked at 180 DEG C-200 DEG C for 18-25 minutes. The obtained egg tart has a significantly reduced cholesterin content, a uniform and compact gel structure, good water retention, a smooth surface, no water separation and no core collapse after baking.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a method for preparing and applying a soybean protein emulsion gel for low-cholesterol egg tarts. Background Technology

[0002] Egg tarts, a popular dessert, are beloved for their sweet taste and unique flavor. The quality of an egg tart largely depends on its filling—the egg custard—which relies on the gel-forming properties of the egg liquid when heated. However, eggs contain high levels of cholesterol (approximately 200-300 mg per egg) and may have a fishy smell, which affects the eating experience for some consumers. Therefore, developing a cholesterol-free, flavor-enhancing plant-based alternative to egg custard has become a pressing issue for the industry.

[0003] In recent years, the food industry has begun exploring the preparation of egg substitutes using plant proteins and polysaccharides as raw materials. By modifying proteins and introducing polysaccharides, and utilizing their gelling properties and interactions, progress has been made in some areas. For example, improvements have been made in protein hydration and chewiness in vegan cake production; good flavor and texture have been achieved in simulated steamed / scrambled egg products; and applications have been explored in mayonnaise-like products. These studies indicate that plant-based substitutes have application potential in specific food systems.

[0004] However, applying plant-based substitutes to egg tart fillings still faces challenges. Existing research is relatively limited, and attempted egg tarts often exhibit problems such as coarse structure, insufficient support, and excessive water separation, affecting the final product quality. Soy protein, due to its good gelling properties, ease of modification, and strong structural plasticity, is considered a potential alternative to egg liquid. However, in the specific application of egg tarts, overcoming the aforementioned technical difficulties to produce a product with a delicate structure, good water retention, and a taste and flavor close to traditional egg tarts requires further in-depth technological development. Summary of the Invention

[0005] The present invention aims to provide a method for preparing and applying a soy protein emulsion gel for low-cholesterol egg tarts. The method involves mixing soy protein isolate with water in a specific ratio to form a protein solution with a mass fraction of 2%–6%. This protein solution is then added to oils, stirred at 60°C, and homogenized under high pressure at 15–25 MPa to obtain a soy protein emulsion. A coagulant is then added, and the mixture is heated at 180–200°C for 18–25 minutes to form a soy protein emulsion gel with a good gel structure. This gel can be used to prepare low-cholesterol egg tarts, resulting in tarts with a fine structure, smooth surface, good water retention, and significantly reduced cholesterol content.

[0006] To achieve the above objectives, this invention provides the following technical solution: a method for preparing and applying a soybean protein emulsion gel for low-cholesterol egg tarts. The first step, preparing the protein solution, uses a mass fraction of 2%-6% to ensure sufficient space for protein molecules to expand and form a continuous network structure. Too low a concentration leads to insufficient gel strength, while too high a concentration may cause premature aggregation of protein molecules, affecting the stability of the emulsion. The second step, mixing the protein solution with oil at 60°C, is crucial. This temperature helps reduce oil viscosity, promotes partial denaturation of proteins, and allows them to adsorb onto the oil-water interface, thus initially stabilizing the emulsion system. Subsequent high-pressure homogenization at 15-25 MPa, through intense shearing, impact, and cavitation, breaks the oil phase into micron- or even submicron-sized droplets, and promotes more effective encapsulation of these droplets by soybean protein, forming a uniform and stable oil-in-water emulsion. The third step, high-temperature heating (180-200°C) after adding a coagulant, is the decisive step in gel formation. At this high temperature, protein molecules fully expand and cross-link, while coagulants (such as calcium salts) can promote the formation of salt bridges between protein molecules, strengthen the gel network, and firmly fix the oil droplets in the three-dimensional network, ultimately forming an emulsion gel with elasticity, hardness, and water retention, laying the textural foundation for replacing egg tart filling.

[0007] Furthermore, the choice of coagulant is another key factor in forming a stable soy protein emulsion gel. The listed coagulants promote protein gelation through different mechanisms of action. Divalent salt coagulants such as calcium sulfate (gypsum), calcium chloride, and magnesium chloride primarily provide calcium or magnesium ions. These ions can electrostatically interact with negatively charged groups (such as carboxyl groups) on the soy protein molecular chains, forming "salt bridges," thereby strengthening the cross-linking between protein molecules and making the gel network more robust and stable. Glucono-δ-lactone (GDL) is an acidic coagulant that slowly hydrolyzes in aqueous solution to generate gluconic acid, gradually lowering the pH of the system. When the pH approaches the isoelectric point of soy protein, the electrostatic repulsion between protein molecules decreases, and the hydrophobic effect increases, thus forming a fine and uniform gel through acid induction. TG enzyme (transglutaminase) is a biological enzyme preparation that catalyzes the covalent cross-linking between the γ-amide group of glutamine residues and the ε-amino group of lysine residues in protein molecules, forming a strong ε-(γ-glutamyl)lysine isopeptide bond. This covalent cross-linking greatly enhances the strength, elasticity, and heat resistance of the gel. Depending on the different product requirements for gel hardness, elasticity, formation speed, and taste, a single coagulant or a combination of multiple coagulants can be flexibly selected to achieve synergistic effects.

[0008] Furthermore, the type and combination of fats directly affect the flavor, texture, and nutritional value of the final egg tart product. Palm oil, especially its fractionated palm oil, is widely used in the baking industry due to its suitable melting point and oxidative stability, helping to give egg tarts a good crispness and creamy texture. Soybean oil and peanut oil, as common vegetable oils, have relatively mild flavors that highlight the sweetness of the egg tart itself, and are rich in unsaturated fatty acids, making them healthier. Coconut oil has a unique coconut flavor, a high melting point, and can give the gel a certain degree of plasticity at room temperature, and may bring a flavor profile similar to butter. Although butter is an animal fat, its unique rich milky aroma is an important part of the traditional egg tart flavor, and its appropriate use can significantly improve the product's flavor acceptance. By scientifically blending these oils, we can leverage their strengths and compensate for their weaknesses. For example, we can use the stability of palm oil as a base oil, combined with a small amount of butter to enhance the flavor, or add coconut oil to adjust the melting characteristics of the gel, thereby designing a plant-based emulsion gel specifically for egg tarts that achieves an ideal balance in terms of texture, flavor, and cost.

[0009] Furthermore, while eggs are the main ingredient in traditional egg tart fillings, their yolks contain high levels of cholesterol, limiting their use for some cardiovascular disease patients or health-conscious consumers. The soybean protein emulsion gel prepared in this invention has a stable microstructure formed by a protein network encapsulating fat globules. Upon heating, it forms a solid-semi-solid state similar to egg gel, perfectly mimicking the function of egg liquid in providing solidification, a delicate texture, lubrication, and flavor carrier in egg tarts. By replacing all or part of the egg liquid with this plant-based gel, the source of cholesterol in the egg tart filling can be fundamentally eliminated.

[0010] Furthermore, each component in the formula has a specific function: 50-80 parts of soy protein emulsion gel is the main component, providing the gel structure and basic texture; 0-25 parts of egg liquid provides flexibility, allowing the amount added to be adjusted according to the product positioning (all-plant-based or low-cholesterol), and a small amount can be added to enhance flavor and color; 1-20 parts of maltose syrup not only provides sweetness, but its maltose and oligosaccharides also have the functions of absorbing moisture and keeping the tart soft, participating in the Maillard reaction to produce an appealing color and flavor; 5-15 parts of white sugar is the main source of sweetness and participates in the formation of caramelized spots on the surface of the egg tart. 0.5-1.5 parts of emulsifier and 0.02-0.1 parts of thickener are key food additives, which further ensure the stability of the egg tart filling system and prevent component separation during resting or baking. The baking temperature and time (180℃-200℃, 18-25min) are optimized parameters that are sufficient to completely denature and coagulate the soy protein and possibly the egg protein, allowing the sugars to fully caramelize and undergo Maillard reactions, resulting in the golden color and sweet flavor characteristic of egg tarts, while ensuring that the center is also fully cooked, forming a delicate and smooth cross-section.

[0011] Furthermore, mono- and diglycerides of fatty acids are among the most widely used emulsifiers. They effectively reduce oil-water interfacial tension, improve emulsion stability, and interact with proteins during baking to improve the final product structure. Polyglycerol fatty acid esters have longer polyglycerol hydrophilic chains, stronger emulsifying ability, and good high-temperature resistance, making them particularly suitable for baked goods. Span 60 (sorbitan monostearate) is a highly lipophilic emulsifier, while Tween 60 (polyoxyethylene sorbitan monostearate) is its corresponding hydrophilic emulsifier. The two are often used in combination, utilizing their different HLB values ​​(hydrophilic-lipophilic balance values) to form a tighter composite film encapsulating fat globules, thus preparing a highly stable emulsion system. During the mixing and baking of egg tart fillings, the synergistic effect of these emulsifiers prevents fat from rising and protein from settling, ensuring a uniform texture and a smooth, gritty consistency in the final egg tart filling.

[0012] Furthermore, the main function of thickeners (more accurately, hydrophilic colloids) is to increase the viscosity of the aqueous phase of the egg tart filling, thereby significantly improving the system's water-holding capacity and stability. Carrageenan, especially κ-carrageenan, can form a firm, brittle gel in the presence of potassium or calcium ions, which helps enhance the shapeability and elasticity of the egg tart filling. Guar gum is a natural colloid with extremely high thickening efficiency; its long-chain molecules can greatly increase the viscosity of the aqueous phase, effectively binding water and reducing moisture loss during baking and cooling, preventing the filling from shrinking and separating, resulting in a more moist texture. Xanthan gum is a pseudoplastic fluid; its solution viscosity decreases with increasing shear force, which is beneficial for the fluidity of the egg tart filling during molding, but it can return to a high viscosity state during standing and baking, providing good suspension stability and water retention. These colloids, when used in combination, can have a synergistic effect. For example, the combination of xanthan gum and guar gum can produce a more viscous solution, which together builds a stable three-dimensional network structure, locks in moisture, and ensures that the egg tarts can maintain a delicate and smooth texture even after being baked at high temperatures.

[0013] Furthermore, the most significant advantage is the substantial reduction or even complete elimination of cholesterol content. This is directly due to the substitution of high-cholesterol egg yolks, meeting the health needs of a specific consumer group. In terms of texture, the uniform network formed by the soy protein gel itself, along with the synergistic stabilizing effect of emulsifiers and thickeners, results in an exceptionally fine and smooth texture for the baked egg tart filling, free from roughness or noticeable holes. The improvement in water retention is particularly prominent. Soy protein has excellent hydration capabilities, and combined with the water-retaining effect of hydrophilic colloids, it effectively reduces moisture evaporation and precipitation during baking and storage.

[0014] Furthermore, after baking at a high temperature of 180℃-200℃, complex physicochemical changes occurred inside the egg tart filling: proteins completely denatured and gelled, sugars caramelized and underwent Maillard reactions, producing an appealing color and flavor. The resulting gel structure was uniform and dense, indicating that the protein network, fat globules, moisture, and other components were highly uniformly distributed throughout the filling, without any areas that were too hard, too soft, or exhibited component separation. The smooth surface reflected rapid and even solidification during baking, without the formation of large air bubbles or cracks due to rapid internal moisture evaporation or unstable components. The absence of significant water separation directly demonstrates good water retention, indicating that the gel network effectively binds moisture, preventing shrinkage and separation even after cooling. The absence of core collapse proves that the gel system possesses sufficient mechanical strength to resist internal stress caused by moisture evaporation and thermal expansion and contraction during cooling, maintaining a full shape and fully verifying the effectiveness of the present invention in achieving a high-quality egg tart texture.

[0015] This invention provides a method for preparing and applying a soybean protein emulsion gel for low-cholesterol egg tarts, which has the following beneficial effects: 1. Significantly improves the smoothness and uniformity of the egg tart gel structure. This invention involves mixing a soy protein isolate solution with vegetable oil at 60°C and homogenizing it under high pressure (15–25 MPa) to form a stable emulsion system. This emulsion is then treated with a coagulant and baked at 180–200°C, resulting in a dense and uniform three-dimensional gel network of soy protein. This gel structure effectively mimics the coagulation behavior of liquid egg during heat processing, giving the egg tart filling a smooth and delicate texture, free of noticeable holes or roughness. Compared to traditional egg tarts made with whole egg liquid, the egg tarts prepared by this invention have a denser cross-sectional structure, avoiding the grainy texture or clumping caused by uneven protein aggregation, thus improving the product's visual appeal and smoothness. Furthermore, the uniform gel structure helps maintain its shape during cutting and chewing, enhancing the consumer's eating experience.

[0016] Effectively reduces the cholesterol content of egg tarts, broadening their appeal to a wider range of consumers. Traditional egg tarts rely on eggs as the main gelling agent, with each egg containing approximately 200–300 mg of cholesterol, posing a health risk to patients with cardiovascular disease or consumers who need to control their blood lipids. This invention uses a soy protein emulsion gel to partially or completely replace the egg liquid, fundamentally eliminating the introduction of animal-derived cholesterol. Soy protein itself contains no cholesterol and is rich in beneficial components such as phytosterols, which help regulate blood lipid metabolism. By adjusting the amount of egg liquid in the egg tart filling (0–25 parts), the cholesterol content can be significantly reduced while maintaining the basic flavor of the egg tart, even achieving a completely cholesterol-free plant-based egg tart product. This meets the needs of vegetarians, lactose-intolerant individuals, and those pursuing a healthy diet, broadening the market applicability.

[0017] Improve the water retention and anti-aging properties of egg tarts, and extend their shelf life. Soy protein possesses excellent hydration and oil-retention properties, forming a stable network structure during baking to effectively lock in moisture and oil, reducing water separation in egg tarts after baking and during storage. The soy protein gel significantly improves the water-holding capacity of egg tarts, preventing the filling from drying out or releasing water, and maintaining a moist texture. Furthermore, this gel system maintains high stability even after frozen storage, delaying starch retrogradation and protein denaturation-induced aging, thus helping to extend the product's sensory quality and shelf life.

[0018] Optimize the flavor and nutritional balance of egg tarts to enhance product competitiveness. This invention introduces maltose syrup, white sugar, and complex emulsifiers (such as mono- and diglycerides of fatty acids, Span 60, etc.) into the egg tart filling. These components work synergistically with soy protein gel, not only mimicking the emulsifying properties of eggs but also imparting a suitable sweetness and aroma to the egg tart. Soy protein itself has a subtle bean aroma, which, through the baking process, undergoes a Maillard reaction with sugars to produce a pleasant baked flavor, masking any potential beany taste. Simultaneously, soy protein is rich in essential amino acids, its nutritional value is similar to that of animal protein, and it contains bioactive substances such as soy isoflavones, allowing the egg tart to lower cholesterol while enhancing its nutritional value. By adjusting the proportions of the components in the egg tart filling, a balance can be achieved between taste, flavor, and nutrition, meeting the modern consumer's demand for both health and deliciousness.

[0019] It possesses good process adaptability and cost advantages, which is conducive to industrialization and promotion. The raw materials used in this invention, such as soy protein isolate, vegetable oil, and coagulants (calcium sulfate, glucono delta-lactone, etc.), are all common food ingredients, widely available, and cheaper than eggs, significantly reducing the production cost of the egg tart filling. The mixing, homogenization, and baking processes involved in the preparation are highly compatible with existing food processing equipment, requiring no additional investment in dedicated production lines and facilitating large-scale production. High-pressure homogenization and high-temperature baking conditions promote the full denaturation and gelation of soy protein, improving process stability and product consistency. Furthermore, the egg tart filling formula is highly flexible, allowing for adjustments to the egg substitution ratio based on market demand, balancing traditional flavors with innovative health benefits, providing food companies with a technically feasible and economically viable path for developing low-cholesterol egg tarts. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0021] Figure 1 This is the overall technical roadmap of the present invention; Figure 2 This is a flowchart illustrating the preparation process of the soybean protein emulsion of this invention. Figure 3 This is a flowchart illustrating the emulsion gel formation process of the present invention. Figure 4 This is a flowchart illustrating the preparation process of the low-cholesterol egg tart filling of the present invention. Figure 5 This is a diagram showing the baking and finished product characteristics of the egg tarts of this invention. Detailed Implementation

[0022] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses consistent with some aspects of this disclosure as detailed in the appended claims.

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Example 1: Fully Alternative Low-Cholesterol Egg Tart This embodiment aims to provide a low-cholesterol egg tart preparation method that completely eliminates the use of egg liquid. First, a soy protein emulsion gel is prepared: Soy protein isolate is accurately weighed and mixed with purified water to prepare a 5.5% (w / w) protein solution. Then, this protein solution is slowly added to refined palm oil preheated to 60°C, maintaining a protein-to-oil mass ratio of 10:1. The mixture is stirred at low speed using a mechanical stirrer in a 60°C constant-temperature water bath to initially form a mixture. Next, the mixture is homogenized using a high-pressure homogenizer at 15 MPa to obtain a stable, fine-grained soy protein emulsion. Then, calcium sulfate, used as a coagulant, is uniformly dissolved in the emulsion. Finally, the mixture is placed in an oven preheated to 180°C and heated for 20 minutes to form a soy protein emulsion gel with a stable three-dimensional network structure. This gel is milky white in color and has a uniform texture.

[0025] After the gel preparation is complete, the egg tart filling is prepared. Accurately weigh 84 parts of the prepared soybean protein emulsion gel (out of a total mass of 100 parts). Add 10 parts maltose syrup for sweetness and color, 5 parts white sugar to enhance sweetness, 0.3 parts mono- and diglycerides of fatty acids and 0.2 parts Span 60 as a complex emulsifier to ensure system stability, and 0.02 parts xanthan gum and 0.02 parts carrageenan as a complex thickener to improve viscosity and water retention. Place all ingredients in a container and mix thoroughly to obtain a smooth, egg-free egg tart filling. Carefully pour the egg tart filling into pre-made tart shells, filling them about eight-tenths full. Place the tart shells filled with egg tart filling in a preheated oven at 180°C and bake for 20 minutes. During baking, the egg tart filling gradually solidifies and forms a gel structure. The finished egg tarts have an appealing light golden-yellow surface. The internal structure, as can be seen through comparison, has a certain degree of self-support, and the inner core does not show obvious collapse. The cross-section is porous. Although there is a small amount of water separation, it has achieved complete replacement of eggs and significantly reduced cholesterol content.

[0026] Example 2: High-protein partial substitute egg tart This embodiment focuses on reducing cholesterol while retaining some of the egg flavor and pursuing a denser texture. The soybean protein emulsion gel is prepared as follows: A soybean protein solution with a mass fraction of 4.7% is prepared. This solution is slowly added to oil at 60°C, with the mass ratio of protein solution to oil controlled at 8:1. After initial emulsification by low-speed stirring, high-pressure homogenization is performed at 15 MPa to obtain an emulsion. The system is then heated in a 200°C oven for 18 minutes to form a relatively hard emulsion gel.

[0027] The egg tart filling was prepared by combining 64 parts soy protein emulsion gel with 10 parts fresh egg liquid to retain some egg flavor, 10 parts malt syrup, 5 parts white sugar, 0.5 parts polyglycerol fatty acid ester as emulsifier, and 0.05 parts guar gum as thickener. All ingredients were mixed thoroughly and then poured into the tart shells. The tarts were baked at 200℃ for 18 minutes. The resulting egg tarts were plump and golden in color. Compared to egg tarts prepared with whole egg liquid, the product in this example has a smooth and dense cross-section, a uniform gel network structure, a smooth surface without obvious pores, good water retention, and a significantly lower cholesterol content compared to traditional egg tarts, resulting in higher overall acceptability.

[0028] Example 3: Egg Tart with Mixed Oil Flavor This embodiment explores the use of blended oils to optimize cost and flavor. First, a protein solution with a mass fraction of 3.0% was prepared. This solution was then mixed with oils preheated to 60°C, with a protein solution to blended oil mass ratio of 12:1. A homogenization pressure of 20 MPa was set to catalyze cross-linking and improve gel strength. Heating at 190°C for 22 minutes resulted in a soy protein emulsion gel with a distinctive nutty flavor.

[0029] The egg tart filling recipe is as follows: 70 parts of the above-mentioned emulsion gel, 15 parts of egg liquid, 5 parts of malt syrup, 10 parts of white sugar, 0.8 parts of Tween 60, and 0.1 parts of carrageenan. After mixing, bake at 190℃ for 22 minutes. The finished egg tarts have a delicate texture, good support, and are cost-effective.

[0030] Example 4: Egg Tart with an Exquisitely Delicate Texture This embodiment aims for an extremely smooth and delicate texture. A 2.2% (w / w) diluted egg white solution is mixed with melted butter (60°C) at a mass ratio of 14:1. Homogenization is performed under high pressure of 25 MPa to ensure high dispersion of the fat particles. A complex of calcium sulfate and magnesium chloride is used as the gelling agent. Gelation is carried out at 185°C for 25 minutes to form a very soft and delicate emulsion gel.

[0031] The egg tart filling contains 50 parts of this delicate gelatin, 25 parts of egg liquid (to maximize the smooth texture), 1 part malt syrup, 15 parts granulated sugar, 1.5 parts Span 60, and 0.02 parts xanthan gum. Bake slowly at 185°C for 25 minutes. The finished egg tart has an extremely delicate and smooth texture, a dense and creamy mouthfeel, and a cholesterol content lower than traditional egg tarts.

[0032] Example 5: Sugar-Health-Oriented Egg Tart This embodiment targets the healthy diet market, emphasizing low sugar content. A high-concentration protein solution with a mass fraction of 6.0% was prepared and mixed at a mass ratio of 15:1. Homogenization pressure was 18 MPa. Gluconolactone was used as a coagulant, and the mixture was heated at 180°C for 25 minutes to form a gel.

[0033] The egg tart filling formula is as follows: 80 parts soy protein emulsion gel, 0 parts egg liquid, 20 parts malt syrup (as the sole sweetener, no added sugar), 0.5 parts mono- and diglyceride fatty acid esters, and 0.06 parts compound thickener (guar gum and xanthan gum in a 1:1 ratio). Bake at 180℃ for 25 minutes. This egg tart contains no added sucrose, relying on malt syrup for sweetness and color, achieving a dual substitution of eggs and added sugar. The product better meets specific health needs, maintains good structure, and does not collapse significantly.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing and applying a low-cholesterol egg tart soy protein emulsion gel, characterized in that... Includes the following steps: a) Mix soy protein isolate with water to prepare a protein solution with a mass fraction of 2%–6%; b) Add the protein solution to the oil, stir and homogenize at 60°C under a pressure of 15–25 MPa to obtain a soybean protein emulsion; c) Add a coagulant and heat at 180–200°C for 18–25 minutes to form an emulsion gel.

2. The preparation method and application of the low-cholesterol egg tart soy protein emulsion gel according to claim 1, characterized in that: In step b), the mass ratio of protein solution to vegetable oil is 15:1 to 8:

1.

3. The preparation method and application of the low-cholesterol egg tart soy protein emulsion gel according to claim 1, characterized in that: The coagulant is one or more of calcium sulfate, magnesium chloride, calcium chloride, gluconolactone, or TG enzyme.

4. The preparation method and application of the low-cholesterol egg tart soy protein emulsion gel according to claim 1, characterized in that: The oil is one or more of palm oil, soybean oil, coconut oil, peanut oil, or butter.

5. The application of the soybean protein emulsion gel obtained by any one of the preparation methods according to claims 1-4 in the preparation of low-cholesterol egg tarts.

6. The preparation method and application of a low-cholesterol egg tart soy protein emulsion gel according to claim 5, characterized in that: a) For every 100 parts, mix 50-80 parts soy protein emulsion, 0-25 parts egg liquid, 1-20 parts malt syrup, 5-15 parts white sugar, 0.5-1.5 parts emulsifier, and 0.02-0.1 parts thickener evenly to obtain the egg tart filling; b) Pour the egg tart filling into the tart shells and bake at 180℃-200℃ for 18-25 minutes.

7. The preparation method and application of a low-cholesterol egg tart soy protein emulsion gel according to claim 6, characterized in that: The emulsifier includes one or more combinations of mono- and diglycerides of fatty acids, polyglycerides of fatty acids, Span 60, and Tween 60.

8. The preparation method and application of a low-cholesterol egg tart soy protein emulsion gel according to claim 6, characterized in that: The thickener includes one or more combinations of carrageenan, guar gum, and xanthan gum.

9. The preparation method and application of a low-cholesterol egg tart soy protein emulsion gel according to any one of claims 7-8, characterized in that: It has significantly reduced cholesterol content, a fine texture, and good water retention.

10. The preparation method and application of a low-cholesterol egg tart soy protein emulsion gel according to claim 6, characterized in that: The egg tart filling, after being baked at 180℃-200℃, forms a uniform and dense gel structure with a smooth surface, no significant water separation, and the egg tart filling does not collapse.

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