Emulsion gel based on ovalbumin-ulva pertusa polysaccharide compound and preparation method thereof

Abstract

The invention provides emulsion gel based on an ovalbumin-ulva pertusa polysaccharide compound and a preparation method of the emulsion gel, and belongs to the technical field of emulsion gel preparation. The emulsion gel based on the ovalbumin-ulva pertusa polysaccharide compound is obtained by heating and cooling an emulsion system, the raw materials of the emulsion system comprise ulva pertusa polysaccharide and ovalbumin, the concentration of the ovalbumin in the emulsion system is 6% (w / v), and the concentration of the ulva pertusa polysaccharide in the emulsion system is 0.1%-0.6% (w / v). According to the invention, ovalbumin and ulva pertusa polysaccharide are taken as emulsifier raw materials, and ovalbumin and ulva pertusa polysaccharide are compounded through electrostatic interaction and hydrophobic interaction, so that the prepared emulsion gel has excellent hardness, water-holding capacity and freeze-thaw stability.

Description

Technical Field

[0001] The invention belongs to the technical field of emulsion gel preparation, and in particular relates to an emulsion gel based on an ovalbumin-Ulva pertusa polysaccharide complex and a preparation method thereof. Background Art

[0002] Ovalbumin (OVA) is the most abundant protein in egg white. OVA is a phosphoglycoglobulin composed of 385 amino acid residues (more than half of which are hydrophobic), and each molecule contains a series of sugar chains that entwine and fold together to form a globular structure. As an important source of animal protein, OVA contains all essential amino acids for the human body, is easily absorbed, and provides rapid energy. OVA is a common dietary food and is widely used in the baking, meat, and other food industries due to its excellent gelling, emulsifying, and foaming properties. Because most of the hydrophobic amino acids are buried within the protein, OVA naturally exists in a hydrophilic form, which hinders its binding to fat-soluble components. OVA's instability near its isoelectric point (pH = 4.7) also limits its application in food. Ulva pertusa is a large green algae belonging to the genus Ulva in the family Ulvaceae of the phylum Chlorophyta. Ulva pertusa has a complex chemical composition, primarily including polysaccharides, proteins, lipids, vitamins, and minerals. Polysaccharides, the most abundant component, possess antibacterial, antioxidant, antiviral, and hypoglycemic properties. Polysaccharides extracted from Ulva pertusa are sulfated heteropolysaccharides with high viscosity and a high hydroxyl content. This suggests that Ulva pertusa polysaccharides have the potential to be used as a new food ingredient in emulsion gels.

[0003] In oil-in-water (O / W) emulsion gels, this colloidal structure can be formed either by the dispersion of emulsion droplets in a continuous gel matrix or by the aggregation of dispersed droplets in a particulate gel. Compared to standard emulsions, emulsion gels have better storage stability and the potential for prolonged intestinal drug release. They also exhibit excellent stability and are commonly used to embed flavor substances. Due to the unstable functional properties of natural proteins, their application is limited. When protein is used alone as an emulsifier, the stability of the emulsion is poor and the strength of the gel formed is not high. To this end, the present invention proposes an emulsion gel based on an ovalbumin-Ulva pertusa polysaccharide complex and a preparation method thereof. Summary of the Invention

[0004] In order to solve the problems in the prior art that the emulsifying ability of a single protein emulsifier is unstable and the strength of the formed gel is not high, the present invention proposes an emulsion gel based on an ovalbumin-Ulva pertusa polysaccharide complex and a preparation method thereof.

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

[0006] One of the technical solutions of the present invention:

[0007] The invention discloses an emulsion gel based on an ovalbumin-Ulva porosus polysaccharide complex. The emulsion gel based on the ovalbumin-Ulva porosus polysaccharide complex is obtained by heating an emulsion system and then cooling it. The raw materials of the emulsion system include Ulva porosus polysaccharide and ovalbumin. The concentration of ovalbumin in the emulsion system is 6% (w / v), and the concentration of Ulva porosus polysaccharide in the emulsion system is 0.1%-0.6% (w / v).

[0008] Preferably, the concentration of Ulva perforata polysaccharide in the emulsion system is 0.3%-0.5% (w / v).

[0009] More preferably, the concentration of Ulva perforata polysaccharide in the emulsion system is 0.3% (w / v).

[0010] Preferably, the raw materials of the emulsion system further include soybean oil, and the amount of soybean oil added to the emulsion system is 20% (v / v).

[0011] (w / v) represents mass-volume concentration, which refers to the mass of solute per unit volume of solution. For example, a 0.3% (w / v) concentration of Ulva porosum polysaccharide in an emulsion solution means that 0.3g of Ulva porosum polysaccharide is present in every 100mL of the emulsion. (v / v) represents volume ratio, which refers to the percentage of solute volume to the total volume of the solution. For example, a 20% (v / v) concentration of soybean oil means that 20mL of soybean oil is present in every 100mL of solution.

[0012] The second technical solution of the present invention:

[0013] A method for preparing the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex comprises the following steps:

[0014] dissolving ovalbumin in water to obtain an ovalbumin solution, dissolving Ulva pertusa polysaccharide in water to obtain an Ulva pertusa polysaccharide solution, and mixing equal volumes of the Ulva pertusa polysaccharide solution and the ovalbumin solution to obtain an ovalbumin-Ulva pertusa polysaccharide complex;

[0015] The ovalbumin-Ulva pertusa polysaccharide complex is added to soybean oil, stirred and dispersed to obtain an emulsion system, and the emulsion system is heated and then cooled to obtain the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex.

[0016] Preferably, the stirring and dispersing speed is 12600 rpm.

[0017] Preferably, the stirring time of the stirring and dispersing is 2 minutes.

[0018] Preferably, the heating is water bath heating.

[0019] Preferably, the water bath heating temperature is 80° C. and the heating time is 30 min.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] (1) The present invention uses ovalbumin and Ulva pertusa polysaccharide as raw materials to obtain a complex, and prepares an emulsion gel based on the synergistic effect of natural biomacromolecules and intermolecular interactions. Ovalbumin is the most abundant protein in egg white, accounting for about 54%. As an important source of animal protein, OVA contains all the amino acids necessary for the human body, is easily absorbed by the human body, and quickly provides energy to the body. Its molecular structure contains a large number of hydrophilic and hydrophobic groups. Ulva pertusa polysaccharide is a natural high-molecular polysaccharide extracted from Ulva pertusa, which has rich functional groups such as hydroxyl and carboxyl groups, and exhibits excellent hydrophilicity, thickening and biological activity. When ovalbumin and Ulva pertusa polysaccharide are mixed in a specific volume ratio, the two are compounded through electrostatic interaction and hydrophobic interaction, thereby forming a denser gel network system, increasing the hardness of the gel, reducing the flow of free water in the gel, and improving the water retention of the gel. In addition, the volume of the ice crystals formed is reduced, thereby improving the freeze-thaw stability.

[0022] (2) During the preparation of the emulsion gel of the present invention, the complex is dispersed in soybean oil. Its unique molecular structure and interactions enable the emulsion system to form a uniform and stable droplet structure during agitation and dispersion. Heating in a water bath denatures the protein, causing the molecular chains to unfold and further entangle with the polysaccharide, forming a denser gel network. Upon cooling, the network structure is fixed, thereby obtaining an emulsion gel. This emulsion gel has the characteristics of being environmentally sustainable, naturally derived, highly nutritious, and having antioxidant and other biological activities.

[0023] (3) From an environmental perspective, the raw materials of the present invention are all natural products and are biodegradable. In terms of nutrition, OVA contains all the amino acids necessary for the human body, is easily absorbed by the human body, and provides rapid energy to the body. Ulva polysaccharide has antioxidant properties, lowers blood lipids, and has immune regulation and other biological activities. In addition, the composite effect of ovalbumin and Ulva polysaccharide gives the emulsion gel excellent hardness, water holding capacity, and freeze-thaw stability. The three-dimensional network structure formed by the composite can effectively bind water molecules and improve water holding capacity; the rigidity and cross-linking degree of the network determine the hardness of the gel; and this stable network structure can resist the damage caused by ice crystal formation and melting during the freeze-thaw process, maintaining the stability of the gel structure, thereby expanding the application range of proteins and polysaccharides, and providing new materials with excellent performance for the fields of food, cosmetics, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 The hardness test results of the emulsion gels prepared in Examples 1-6 and Comparative Example 1 are as follows;

[0026] Figure 2 The water holding capacity analysis results of the emulsion gels prepared in Examples 1-6 and Comparative Example 1;

[0027] Figure 3 The freeze-thaw stability test results of the emulsion gels prepared in Examples 1-6 and Comparative Example 1 are shown. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] An embodiment of the present invention proposes an emulsion gel based on an ovalbumin-Ulva porosus polysaccharide complex. The emulsion gel based on the ovalbumin-Ulva porosus polysaccharide complex is obtained by heating an emulsion system and then cooling it. The raw materials of the emulsion system include Ulva porosus polysaccharide and ovalbumin. The concentration of ovalbumin in the emulsion system is 6% (w / v), and the concentration of Ulva porosus polysaccharide in the emulsion system is 0.1%-0.6% (w / v).

[0034] In a preferred embodiment of the present invention, preferably, the concentration of Ulva pertusa polysaccharide in the emulsion system is 0.3%-0.5% (w / v), and more preferably, the concentration of the Ulva pertusa polysaccharide solution is 0.3% (w / v).

[0035] In a preferred embodiment of the present invention, the raw materials of the emulsion system further include soybean oil, and the amount of soybean oil added to the emulsion system is 20% (v / v).

[0036] In the examples of the present invention, (w / v) refers to mass volume concentration, which refers to the mass of the solute contained in each unit volume of the solution. For example, a concentration of 0.3% (w / v) of Ulva pertusa polysaccharide solution means that 100 mL of the emulsion system contains 0.3 g of Ulva pertusa polysaccharide. In the examples of the present invention, (v / v) refers to volume ratio, which refers to the percentage of the solute volume to the total volume of the solution. For example, a concentration of 20% (v / v) of soybean oil means that 100 mL of the solution contains 20 mL of soybean oil.

[0037] If the concentration of the ovalbumin solution is too low (e.g., <6%), the intermolecular interactions will be weakened. Insufficient ovalbumin concentration will reduce the number of protein molecules in the system, resulting in insufficient hydrogen bonds and hydrophobic interaction sites between molecules, making it difficult to build a tight three-dimensional network structure. As a result, the prepared emulsion gel network has insufficient support and the gel is not easy to completely solidify. If the concentration of the ovalbumin solution is too high (e.g., >6%), the intermolecular interactions between high-concentration proteins will be too strong, forming rigid aggregates rather than a uniform network, causing a surge in the viscosity of the system and even protein precipitation. Rigid aggregates make the gel texture too hard, but lack flexibility and are easy to break. Excessive cross-linking restricts the movement of molecular chains, making it difficult for the gel to rebound after being compressed, showing a "rigid" characteristic. In addition, high protein concentrations may inhibit the binding of polysaccharides to proteins through charge shielding (e.g., Ulva pertusa polysaccharides contain negatively charged groups, which are blocked from binding to positively charged sites on proteins), thereby weakening the synergistic effect of the complex.

[0038] As a co-emulsifier and gel enhancer, Ulva pertusa polysaccharide cannot effectively adsorb at the oil droplet interface or fill the gaps in the protein network at too low a concentration. This results in the oil droplet interface membrane being stabilized solely by the protein. Lacking the steric hindrance of the polysaccharide, it is prone to Ostwald ripening or flocculation. The polysaccharide cannot form a sufficient "filling skeleton," resulting in reduced gel hardness and cohesion, a loose texture, and a lack of the polysaccharide's hydrogen bond network to bind water. The gel is prone to structural collapse due to ice crystal extrusion during freeze-thaw cycles, resulting in severe syneresis. At high concentrations (>0.6%), the molecular chains of the polysaccharide entangle with each other, forming a viscous network independent of the protein. This weakens the complexing effect with the protein and may even cause phase separation. The polysaccharide entanglement forms a rigid gel, but it has poor synergy with the protein network, resulting in a rough and brittle texture. Although the polysaccharide itself has antioxidant properties, at too high a concentration, its active groups may not be fully exposed due to intramolecular hydrogen bonding, resulting in limited or even decreased antioxidant properties.

[0039] In the embodiment of the present invention, the concentration of ovalbumin in the emulsion system is limited to 6% (w / v), and the concentration of Ulva perforata polysaccharide in the emulsion system is limited to 0.1%-0.6% (w / v). This is because:

[0040] If the egg albumin concentration is too low, it cannot be completely solidified to form a gel through heat induction. If the protein concentration is too high, the protein cannot be completely and evenly dissolved. Therefore, 6% (w / v) is selected as the optimal protein concentration. Insufficient polysaccharides will lead to a decrease in the viscosity of the system and thus fail to restrict the flow of free water. At the same time, the content of hydrophilic amino acids and charged particles will decrease, and the electrostatic interaction between proteoglycans will be weakened. If the polysaccharide ratio is too high, the polysaccharide molecules will undergo structural rearrangement on the surface of the emulsion, the molecular chains will become entangled, and the soluble free chain segments will be reduced. At the same time, there is a charge shielding effect, which leads to a decrease in the ionization degree of hydrophilic groups such as carboxyl groups, reducing electrostatic repulsion and hydration capacity. Therefore, the polysaccharide concentration is limited to 0.1%-0.6% (w / v).

[0041] The present invention also provides a method for preparing the above-mentioned emulsion gel based on ovalbumin-Ulva pertusa polysaccharide complex, comprising the following steps:

[0042] dissolving ovalbumin in water to obtain an ovalbumin solution, dissolving Ulva pertusa polysaccharide in water to obtain an Ulva pertusa polysaccharide solution, and mixing the Ulva pertusa polysaccharide solution and the ovalbumin solution to obtain an ovalbumin-Ulva pertusa polysaccharide complex;

[0043] The ovalbumin-Ulva pertusa polysaccharide complex is added to soybean oil, stirred and dispersed to obtain an emulsion system, and the emulsion system is heated and then cooled to obtain an emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex.

[0044] In a preferred embodiment of the present invention, the stirring and dispersing speed is 12600 rpm and the stirring time is 2 min.

[0045] In a preferred embodiment of the present invention, the water bath heating temperature is 80° C. and the heating time is 30 min.

[0046] In the embodiments of the present invention, the ovalbumin used was purchased from Shanghai Yuanye Biotechnology Co., Ltd., and the Ulva pertusa polysaccharide was prepared according to the crude polysaccharide extraction method described in the reference (Gao Xin. Research on the structure of Ulva pertusa polysaccharide and the immune function of its iron (III) complex [PhD] 2021.).

[0047] During the performance testing of the embodiments of the present invention, each experiment was repeated three times, and data were statistically analyzed using IBM SPSS Statistics 23 software. Differences between groups were compared using one-way analysis of variance and post hoc analysis. The results are expressed as mean ± standard deviation (mean + SD). A significant difference between the two groups was considered when p < 0.05 within the 95% confidence interval.

[0048] The technical solution of the present invention is further illustrated by the following examples.

[0049] Example 1

[0050] A method for preparing an emulsion gel based on an ovalbumin-Ulva pertusa polysaccharide complex comprises the following steps:

[0051] A certain amount of ovalbumin (OVA) powder was weighed and dissolved in distilled water to obtain an ovalbumin solution, which was magnetically stirred for 2 h and then stored in a refrigerator at 4°C overnight.

[0052] A certain amount of Ulva pertusa polysaccharide powder was weighed and dissolved in distilled water to prepare a Ulva pertusa polysaccharide solution, which was stirred with magnetic stirring for 2 h and then stored in a refrigerator at 4°C overnight.

[0053] The prepared Ulva pertusa polysaccharide solution and ovalbumin solution were mixed and stirred to obtain an ovalbumin-Ulva pertusa polysaccharide complex, the ovalbumin-Ulva pertusa polysaccharide complex was added to soybean oil, and stirred and dispersed at 12600 rpm for 2 min to obtain an emulsion system (the concentration of ovalbumin was 6% (w / v), the concentration of Ulva pertusa polysaccharide was 0.1% (w / v), and the amount of soybean oil added was 20% (v / v)), the emulsion system was heated in a water bath at 80°C for 30 min, and after cooling in cold water, an emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex was obtained, which was stored in a refrigerator at 4°C.

[0054] Example 2

[0055] The same as Example 1, except that the concentration of Ulva perforata polysaccharide in the emulsion system is 0.2% (w / v).

[0056] Example 3

[0057] The same as Example 1, except that the concentration of Ulva perforata polysaccharide in the emulsion system is 0.3% (w / v).

[0058] Example 4

[0059] The same as Example 1, except that the concentration of Ulva perforata polysaccharide in the emulsion system is 0.4% (w / v).

[0060] Example 5

[0061] The same as Example 1, except that the concentration of Ulva perforata polysaccharide in the emulsion system is 0.5% (w / v).

[0062] Example 6

[0063] The same as Example 1, except that the concentration of Ulva perforata polysaccharide in the emulsion system is 0.6% (w / v).

[0064] Comparative Example 1

[0065] The same as Example 3, except that the concentration of Ulva pertusa polysaccharide in the emulsion system is 0% (w / v), that is, no Ulva pertusa polysaccharide is added. The method specifically comprises the following steps:

[0066] A certain amount of ovalbumin (OVA) powder was weighed and dissolved in distilled water to prepare an ovalbumin solution, which was magnetically stirred for 2 h and then stored in a 4°C refrigerator overnight.

[0067] The prepared ovalbumin solution was added to soybean oil, stirred and dispersed at 12600 rpm for 2 min to obtain an emulsion system (the concentration of ovalbumin was 6% (w / v), and the amount of soybean oil added was 20% (v / v)). The emulsion system was heated in a water bath at 80°C for 30 min, cooled in cold water to obtain an ovalbumin-based emulsion gel, and stored in a refrigerator at 4°C.

[0068] Comparative Example 2

[0069] The same as Example 3, except that the concentration of ovalbumin is 0% (w / v), i.e., no ovalbumin is added, specifically comprising the following steps:

[0070] A certain amount of Ulva pertusa polysaccharide powder was weighed and dissolved in distilled water to prepare a Ulva pertusa polysaccharide solution, which was stirred with magnetic stirring for 2 h and then stored in a refrigerator at 4°C overnight.

[0071] The prepared Ulva pertusa polysaccharide solution was added to soybean oil, stirred and dispersed at 12600 rpm for 2 min to obtain an emulsion system (the concentration of Ulva pertusa polysaccharide was 0.3% (w / v), and the amount of soybean oil added was 20% (v / v)). The emulsion system was heated in a water bath at 80°C for 30 min, cooled in cold water to obtain an emulsion gel based on Ulva pertusa polysaccharide, and stored in a refrigerator at 4°C.

[0072] Ovalbumin can form a three-dimensional network of hydrogen bonds and hydrophobic interactions with Ulva pertusa polysaccharide to provide support for the gel. In this comparative example, when the ovalbumin solution was omitted, the network structure formed by Ulva pertusa polysaccharide alone was not strong enough to form a gel.

[0073] Comparative Example 3

[0074] Same as Example 3, except that the concentration of ovalbumin in the emulsion system is 5% (w / v).

[0075] This comparative example cannot form an emulsion gel because, the lower the ovalbumin concentration, the fewer hydrophobic groups and thiol groups are consumed during the aggregate binding process. Through this process, the surface hydrophobicity and -SH content of the aggregates are also reduced, and the size and number of the aggregates formed are reduced; the reduction in protein concentration weakens the force of protein molecules to bind into aggregates, and thus the structure of protein aggregates cannot be compacted to form.

[0076] Performance Testing

[0077] (1) Texture test

[0078] The emulsion gel samples prepared in each comparative example and example were placed directly on the sample stage of a texture analyzer for texture testing. TPA mode was used, with a cylindrical probe of p / 0.5, a pre-test speed of 5 mm / s, a test speed of 1 mm / s, a post-test speed of 5 mm / s, and a deformation degree of 70%.

[0079] The hardness test results of the emulsion gels prepared in Examples 1-6 and Comparative Example 1 are shown in Figure 1 (Examples 1-6 in the figure represent emulsion gels prepared with a 6% egg white protein emulsion system containing Ulva porosiformis polysaccharide at a concentration of 0.1% to 0.6%, and Comparative Example 1 represents an emulsion gel prepared with a 6% egg white protein emulsion system containing Ulva porosiformis polysaccharide at a concentration of 0.0%, i.e., without adding Ulva porosiformis polysaccharide, the same below). Figure 1 As the concentration of Ulva pertusa polysaccharide increases, the gel hardness increases significantly, indicating a denser gel structure. However, at high concentrations, the difference in gel hardness is not significant. This may be because the polysaccharide is slightly saturated at this point, and the addition of saturated polysaccharide limits cross-linking between polymers. Furthermore, polysaccharide molecules on the surface of the emulsion droplets may rearrange, leading to aggregation between droplets and performance degradation.

[0080] (2) Water holding capacity analysis

[0081] Accurately weigh 5 g of each emulsion gel prepared in the application example, wrap it with filter paper, and place it in a 50 mL centrifuge tube. Centrifuge the sample at 8000 rpm for 10 min in a 4°C low-temperature high-speed centrifuge. Calculate the water holding capacity (WHC) of the sample based on the change in mass of the emulsion gel before and after centrifugation using the following formula:

[0082] WHC (%) = (M1 / M0) × 100%

[0083] Where M0 and M1 are the mass of the sample before and after centrifugation, respectively.

[0084] High water retention gel food can effectively resist the structural shrinkage caused by water loss, which reflects the strength and stability of the gel. The water holding capacity analysis results of the emulsion gels prepared in Examples 1-6 and Comparative Example 1 are shown in Figure 2 ,Depend on Figure 2 It can be seen that the addition of Ulva pertusa polysaccharide significantly increased the WHC of the gel (P<0.05), reaching a maximum when the polysaccharide addition was 0.3%, and then the water holding capacity tended to be stable as the polysaccharide addition increased. This shows that the addition of Ulva pertusa polysaccharide makes the gel structure more uniform and dense. However, when the concentration of Ulva pertusa polysaccharide is 0.6%, the water holding capacity of the gel is slightly reduced. This may be because when the polysaccharide concentration is too high, an overly dense cross-linked network is formed between molecules, resulting in an overly tight gel network. The water is locked in the rigid network, making it difficult to retain free water through hydrogen bonds or capillary action. This is consistent with the texture analysis results.

[0085] (3) Freeze-thaw stability test

[0086] The freeze-thaw stability of an emulsion gel can be measured by measuring its syneresis shrinkage after freeze-thaw cycles. 5 g of each emulsion gel prepared in the application example was centrifuged at 1000 g for 15 minutes to remove excess water. The weight obtained after centrifugation was defined as the initial weight. The centrifuged sample was then frozen at -20°C for 22 hours and thawed at 37°C for 2 hours. The sample was then centrifuged and weighed under the same conditions for five cycles. The degree of weight loss, i.e., shrinkage (%), was expressed as a percentage of the initial sample weight.

[0087] The freeze-thaw stability test results of the emulsion gels prepared in Examples 1-6 and Comparative Example 1 are shown in Figure 3 ,Depend on Figure 3It can be seen that after 5 freeze-thaw cycles, all emulsion gels showed varying degrees of dehydration. This is attributed to the irreversible damage to the gel network caused by the generation and growth of ice crystals during the frozen storage process, which resulted in larger pores and structural collapse in the gel network of the emulsion due to the melting and dehydration of ice crystals after thawing. As the concentration of Ulva pertusa polysaccharide increased to 0.3%, the dehydration shrinkage rate of the emulsion gel decreased significantly. This is mainly attributed to the formation of a denser network structure due to the increase in polysaccharide concentration, thus showing better freeze-thaw stability. When the polysaccharide addition amount reached 0.5% and 0.6%, the dehydration shrinkage rate increased slightly. This may be because the polysaccharide addition amount was too high, and the strong hydrophilicity would competitively bind a large amount of free water, resulting in a reduction in free water in the system, and thus a slight increase in the shrinkage rate.

[0088] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An emulsion gel based on an ovalbumin-Ulva pertusa polysaccharide complex, characterized in that: The emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex is obtained by heating an emulsion system and then cooling it. The raw materials of the emulsion system include Ulva pertusa polysaccharide and ovalbumin. The concentration of ovalbumin in the emulsion system is 6% (w / v), and the concentration of Ulva pertusa polysaccharide in the emulsion system is 0.1%-0.6% (w / v).

2. The emulsion gel based on ovalbumin-Ulva pertusa polysaccharide complex according to claim 1, characterized in that: The concentration of Ulva perforata polysaccharide in the emulsion system is 0.3%-0.5% (w / v).

3. The emulsion gel based on ovalbumin-Ulva pertusa polysaccharide complex according to claim 2, characterized in that: The concentration of Ulva perforata polysaccharide in the emulsion system is 0.3% (w / v).

4. The emulsion gel based on ovalbumin-Ulva pertusa polysaccharide complex according to claim 1, characterized in that: The raw materials of the emulsion system also include soybean oil.

5. The emulsion gel based on ovalbumin-Ulva pertusa polysaccharide complex according to claim 4, characterized in that: The amount of soybean oil added to the emulsion system is 20% (v / v).

6. A method for preparing an emulsion gel based on an ovalbumin-Ulva pertusa polysaccharide complex according to any one of claims 1 to 5, characterized in that: The following steps are involved: dissolving ovalbumin in water to obtain an ovalbumin solution, dissolving Ulva pertusa polysaccharide in water to obtain an Ulva pertusa polysaccharide solution, and mixing the Ulva pertusa polysaccharide solution and the ovalbumin solution to obtain an ovalbumin-Ulva pertusa polysaccharide complex; The ovalbumin-Ulva pertusa polysaccharide complex is added to soybean oil, stirred and dispersed to obtain an emulsion system, and the emulsion system is heated and then cooled to obtain the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex.

7. The method for preparing the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex according to claim 6, characterized in that: The stirring and dispersing rotation speed is 12600 rpm.

8. The method for preparing the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex according to claim 6, characterized in that: The stirring time of the stirring and dispersing is 2 minutes.

9. The method for preparing the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex according to claim 6, characterized in that: The heating is water bath heating.

10. The method for preparing the emulsion gel based on the ovalbumin-Ulva pertusa polysaccharide complex according to claim 6, characterized in that: The water bath was heated at 80° C. for 30 min.

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