Corn glycerin-based oleogel based on polyphenol self-assembled coating, its preparation method and application

Abstract

This application relates to the field of food processing technology, specifically to a zein-based oleogloss with a polyphenol self-assembled coating, its preparation method, and its application. The preparation method includes the following steps: dissolving zein in an ethanol-water solution, adjusting the pH to 10-12 for pretreatment, and removing the ethanol by heating and stirring at 30-50°C to obtain a zein dispersion; first adding epigallocatechin gallate, then adding Ca... 2+ A composite particle dispersion was prepared; the composite particle dispersion was mixed with liquid oil to prepare a Pickering emulsion, which was then dried in the dark with cold air to obtain a solid fat; the solid fat was dispersed to prepare a zein-based oleogel based on a polyphenol self-assembled coating; zein, Ca... 2+ The ratio of epigallocatechin gallate to ethyl gallate is 2g:0.05mmol:0.05mmol. The preparation method described in this application is simple and environmentally friendly, suitable for mass production. The prepared zein-based oleogel exhibits good stability, strength, and resistance to deformation, and is not easily oxidized.

Description

Technical Field

[0001] This application relates to the field of food processing technology, specifically to a zein-based oleogel based on a polyphenol self-assembly coating, its preparation method, and its application. Background Technology

[0002] Solid fats are fats that solidify at room temperature. Solid fats can increase the crispness and texture of food, enrich people's taste experience, and affect the quality of food. They are an important component in food processing.

[0003] Solid fats mainly come from animal fats, such as lard and tallow. Animal fats usually contain high levels of saturated fatty acids. Excessive intake of saturated fatty acids increases the risk of cardiovascular and cerebrovascular diseases. In contrast, plant fats contain a large amount of unsaturated fatty acids, which helps reduce the risk of cardiovascular and cerebrovascular diseases.

[0004] For the sake of human health, the "Chinese Dietary Guidelines" recommends replacing solid fats with unsaturated fatty acids. However, unsaturated fatty acids are generally in liquid form, and the process of converting them into solids easily produces saturated / trans fatty acids. Trans fatty acids increase the viscosity and coagulation of human blood, easily leading to the formation of blood clots. They may also affect development and impair memory. The U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have enacted regulations to prohibit the use of artificial trans fats and encourage the use of healthier oils to replace them.

[0005] Therefore, it is urgent to seek a solid fat with low trans fatty acid and low saturated fatty acid content for use in food processing. Summary of the Invention

[0006] This application aims to overcome at least one of the defects of the prior art and provide a zein-based oleogel based on a polyphenol self-assembled coating, its preparation method and application. The zein-based oleogel has good stability, good strength and resistance to deformation, is not easily oxidized, and its preparation method is simple and environmentally friendly, making it suitable for mass production.

[0007] In a first aspect, embodiments of this application provide a method for preparing a zein-based oleogel based on a polyphenol self-assembled coating, achieved through the following technical solution:

[0008] A method for preparing a zein-based oleogel based on a polyphenol self-assembled coating includes the following steps:

[0009] S1. Dissolve zein in an ethanol-water solution, adjust the pH to 10-12 for pretreatment, and remove the ethanol by heating and stirring at 30-50℃ to obtain a zein dispersion.

[0010] S2. First add epigallocatechin gallate (EGCG), then add Ca. 2+ A composite particle dispersion was prepared;

[0011] S3. The composite particle dispersion is mixed with liquid oil to prepare Pickering emulsion, which is then dried in the dark and in cold air to obtain solid fat;

[0012] S4. The solid fat is dispersed to obtain a zein-based oleogel with a polyphenol self-assembly coating;

[0013] The zein, the Ca 2+ The ratio of the amount of the above-mentioned gallic acid catechin gallate to that of the gallic acid catechin gallate is 2g:0.05mmol:0.05mmol.

[0014] The method for preparing a zein-based oleogel based on a polyphenol self-assembled coating according to an embodiment of this application has at least the following beneficial effects:

[0015] The preparation method described in this application is simple, environmentally friendly, and suitable for mass production. Liquid oleogel formation is achieved using an emulsion template method. Hydrocolloids are initially dispersed in an aqueous phase to emulsify liquid oil. Water is then removed to obtain a polymer network of tightly packed oil droplets. Finally, the polymer network is sheared to induce oleogel formation. The emulsion interface strength is a crucial factor in constructing stable oleogels using the emulsion template method.

[0016] The zein in this application provides emulsification. Zein is rich in sulfur-containing amino acids. The protein molecules are linked by strong disulfide bonds and hydrophobic bonds. When the film-forming solution is applied, the protein aggregates and forms hydrogen bonds, disulfide bonds and hydrophobic bonds between molecules to maintain the network structure of the film, forming a transparent and glossy zein film that encapsulates oils, blocks oxygen, and enhances antioxidant properties.

[0017] Different polyphenols have different structures and functional groups, resulting in varying affinities for proteins and different sites during covalent cross-linking. Different reaction conditions are required when different types of polyphenols combine with different types of proteins. The epigallocatechin gallate ester of this application has a larger number of phenolic hydroxyl groups, exhibiting different main interactions compared to phenolic acids. It has a stronger binding ability to zein, reacting with zein molecules or groups through hydrogen bonds, covalent bonds, and coordinate bonds. It possesses strong interfacial adsorption capabilities, adhering to the surface of zein molecules to form a polyphenol self-assembled coating. This self-assembled coating enhances emulsion bridging or flocculation, promoting emulsion stability and improving interfacial stability. Consequently, the prepared zein-based oleogel exhibits stronger strength, resistance to deformation, and antioxidant properties.

[0018] Ca 2+ It can form chelates with epigallocatechin gallate and zein, enhancing the structural strength of the polyphenol self-assembled coating. The chelates also further improve the scavenging activity against hydroxyl radicals, thereby improving the thermal stability and antioxidant properties of the prepared zein-based oleogloss.

[0019] In this application, controlling the pH value to 10-12 is beneficial for the dispersion of zein. Epigallocatechin gallate is also easily dissolved at alkaline pH due to deprotonation. This facilitates the dissolution of zein-epigallocatechin gallate-Ca... 2+ The interactions between these components provide more sites, facilitating the formation of covalent complexes and enhancing the structural strength of polyphenol self-assembled coatings. Furthermore, a pH of 10-12 not only easily controls the alkalinity of the ethanol-water solution of zein, but also facilitates the subsequent preparation of oleogels, allowing for better control of Ca2+. 2+ A small amount of alkaline solution can react with carbon dioxide in the air to form calcium carbonate, which coats the surface of the oleogel. This reduces the contact between unsaturated fatty acids in the oleogel and air, improving the antioxidant properties of the prepared oleogel. Furthermore, the generated calcium carbonate particles are small, enhancing the strength and resistance to deformation of the prepared oleogel. However, proteins are easily hydrolyzed under strongly alkaline conditions; only a suitable pH value can achieve the effects described in this application.

[0020] The proportions of components in this application facilitate the adjustment of zein and Ca... 2+ The combined effect of zein and epigallocatechin gallate: the number of binding sites on the zein molecule is fixed. When the number of binding sites of zein and epigallocatechin gallate is approximately the same, intermolecular cross-linking is strengthened, forming a network structure, and the amount of complex formed is maximized. Excessive zein content may affect the deformation resistance of the prepared oleogel. (Ca...) 2+Excessive concentration can affect the formation of oleogastrone, and the content of epigallocatechin gallate has a significant impact on interfacial stability.

[0021] In step S3 of this application, the use of light-protected cold air drying can quickly remove moisture, with low energy consumption during the drying process. At the same time, oxidation reaction is less likely to occur during the drying process, reducing the peroxide value and thiobarbituric acid value of the prepared zein-based oleogel.

[0022] According to some embodiments of this application, the pH value of the pretreatment in step S1 is 10. A suitable pH value can further enhance the structural strength of the polyphenol self-assembled coating, while an excessively high pH value can easily lead to protein hydrolysis.

[0023] According to some embodiments of this application, step S1, before removing ethanol, further includes adding and mixing a tris(hydroxymethyl)aminomethane (Trometamol, or Tris) buffer solution. The Tris buffer solution in this application can maintain the stability of the solution and keep the pH value relatively stable, which is beneficial for preparing structurally stable oleogels.

[0024] According to some embodiments of this application, the heating temperature in step S1 is 35-45°C, for example, 40°C. Controlling the temperature appropriately allows for the removal of some water while removing ethanol, facilitating the adjustment of the concentration of the prepared zein dispersion.

[0025] According to some embodiments of this application, before the pretreatment described in step S1, the zein is further stored in an environment of 2-8°C for 7-12 hours. Storing zein in an ethanol-water solution for a certain period of time is beneficial for the complete dispersion of zein, resulting in a more uniform particle size of the zein dispersion.

[0026] According to some embodiments of this application, the volume ratio of ethanol-water solution in step S1 is 80% (V / V). When the volume ratio of ethanol-water solution is 80% (V / V), the dispersibility of zein is better, and the particle size of the resulting zein dispersion is uniform.

[0027] According to some embodiments of this application, step S2 is performed under stirring conditions at a speed of 1000-2000 rpm. Rapid stirring can accelerate the reaction of zein and calcium. 2+ The dispersion rate of epigallocatechin gallate increases, making the reaction more complete and enhancing the bridging or flocculation of the emulsion.

[0028] According to some embodiments of this application, after the composite particle dispersion is mixed with the liquid oil in step S3, ultrasonic cell disruption treatment is also included.

[0029] Furthermore, the parameters of the ultrasonic crushing treatment are set to 600W, 3s on, 3s off, and 10-15min. For example, the parameters of the ultrasonic crushing treatment are set to 600W, 3s on, 3s off, and 12min.

[0030] According to some embodiments of this application, the time for light-protected cold air drying in step S3 is 18-30 hours, for example, 24 hours.

[0031] According to some embodiments of this application, the liquid oil in step S3 is liquid vegetable oil.

[0032] Furthermore, the liquid vegetable oil includes at least one of corn oil, peanut oil, soybean oil, flaxseed oil, castor oil, rapeseed oil, walnut kernel oil, safflower seed oil, schisandra seed oil, sage seed oil, olive oil, sea buckthorn seed oil, and tea oil, for example, the liquid vegetable oil is corn oil.

[0033] According to some embodiments of this application, the parameters for dispersion processing in step S4 are 8000-12000 rpm, for example, 10000 rpm.

[0034] Furthermore, the dispersion processing time is 0.5-2 minutes, for example, 1 minute.

[0035] Secondly, the embodiments of this application provide the zein-based oleogel prepared by the above-mentioned method for preparing zein-based oleogel with a polyphenol self-assembled coating.

[0036] According to some embodiments of this application, the elastic modulus of the zein-based oleogel based on the polyphenol self-assembled coating is 10. 4 -10 5 Pa.

[0037] Furthermore, the zein-based oleogel based on the polyphenol self-assembled coating has a peroxide value of 0.48-0.53 meq / kg and a thiobarbituric acid value of 0.0064-0.0068 mg malondialdehyde / kg.

[0038] The zein-based oleogel prepared in this application, based on a polyphenol self-assembled coating, exhibits good stability, strength, and resistance to deformation, as well as good extrudability and resistance to oxidation.

[0039] Thirdly, embodiments of this application provide the application of the above-mentioned zein-based oleogel with a polyphenol self-assembly coating in the production of solid or semi-solid foods. Attached Figure Description

[0040] Figure 1This is a particle size diagram of the zein composite particles coated with a polyphenol self-assembled coating prepared in Examples 1-4 of this application.

[0041] Figure 2 This is a particle size diagram of the zein composite particles coated with a polyphenol self-assembled coating prepared in Examples 5-8 of this application.

[0042] Figure 3 This is a particle size distribution diagram of the Pickering emulsions prepared in Examples 1-8 and Comparative Example 1 of this application.

[0043] Figure 4 These are extrudability appearance diagrams of the zein-based oleogels based on polyphenol self-assembled coatings prepared in Examples 1-8 of this application and the zein-based oleogels prepared in Comparative Example 1.

[0044] Figure 5 These are elastic modulus diagrams of the zein-based oleogels based on polyphenol self-assembled coatings prepared in Examples 1-8 of this application and the zein-based oleogels prepared in Comparative Example 1.

[0045] Figure 6 The values ​​are the peroxide value and thiobarbituric acid value of the zein-based oleogels based on polyphenol self-assembled coatings prepared in Examples 1-8 of this application and the zein-based oleogels prepared in Comparative Example 1. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description will be provided below in conjunction with specific embodiments. The embodiments described herein are merely some examples of this application and should not be construed as limiting the scope of protection of this application.

[0047] Example 1

[0048] The preparation of zein-based oleogloss based on a polyphenol self-assembled coating includes the following steps:

[0049] S1. Weigh 2.0 g of zein powder, add 100 mL of 80% (V / V) ethanol-water solution, stir magnetically for 2 h until completely dissolved, store the resulting solution at 4 ℃ for 10 h, adjust the pH of the solution to 10, slowly add an equal volume of 10 mmol / L Tris buffer under magnetic stirring, and then remove ethanol and some water by magnetic stirring at 40 ℃ to obtain a 2 wt% zein dispersion, named Z;

[0050] S2. While stirring at 1500 rpm, add 1000 μL of 12.5 mmol / L Ca2+ to the corn gliadin dispersion obtained in step S1. 2+The solution (the resulting solution is named ZCa) is then added to 1000 μL of 50 mmol / L EGCG solution to prepare a dispersion of zein-coated polyphenol self-assembly coating particles, named ZCaE1.

[0051] S3. The dispersion of zein composite particles coated with the polyphenol self-assembled coating obtained in step S2 was mixed with corn oil and subjected to ultrasonic cell disruption treatment to obtain Pickering emulsion, named ZCaE1-PE; the ultrasonic cell disruption parameters were set as follows: 600W, 3s on, 3s off, working for 12min; the obtained Pickering emulsion was placed in a fume hood in the dark and dried in cold air for 24h to remove moisture, thus obtaining solid fat.

[0052] S4. The solid fat obtained in step S3 is subjected to high-speed dispersion treatment at 10,000 rpm for 1 min to obtain zein-based oleogel, named ZCaE1-O.

[0053] Reference Figure 1 After measurement, the particle size of Z was 334.23±2.75nm and PDI<0.3; the particle size of ZCaE1 was 343.80±4.93nm and PDI<0.3, indicating that zein composite particles coated with polyphenol self-assembly coating were formed in step S2.

[0054] Reference Figure 3 After measurement, the particle size distribution of the obtained ZCaE1-PE was found to be multi-peaked (main peak ~1μm, small peak ~100μm).

[0055] Reference Figure 4 After testing, the obtained ZCaE1-O showed good extrudability.

[0056] Reference Figure 5 After measurement, the elastic modulus of ZCaE1-O was found to be 10. 4 -10 5 Pa.

[0057] Reference Figure 6 After testing, the peroxide value of the obtained ZCaE1-O was 0.56 meq / kg, and the thiobarbituric acid value was 0.0072 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0058] Example 2

[0059] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembly coating in Example 1, the difference in this example is that in step S2, the added Ca... 2+ The solution is 1000 μL of 25 mmol / L Ca2+ The solution preparation steps were the same as in Example 1. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZCaE2, the Pickering emulsion was named ZCaE2-PE, and the zein-based oleogel was named ZCaE2-O.

[0060] Reference Figure 1 After measurement, the particle size of the obtained ZCaE2 was 360.43±5.20nm, and the PDI<0.3.

[0061] Reference Figure 3 ( Figure 3 The "-PE" in the name of ZCaE2-PE in the figure is not fully displayed in the figure. The same problem exists for ZCaE5-PE, ZECa2-PE and ZECa5-PE. This is explained here for the purpose of understanding the contents of this application. After measurement, the particle size distribution of the obtained ZCaE2-PE is a single peak (~1μm).

[0062] Reference Figure 4 After testing, the obtained ZCaE2-O showed good extrudability.

[0063] Reference Figure 5 After measurement, the elastic modulus of ZCaE2-O was found to be 10. 4 ~10 5 Pa.

[0064] Reference Figure 6 After testing, the peroxide value of the obtained ZCaE2-O was 0.51 meq / kg, and the thiobarbituric acid value was 0.0071 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0065] Example 3

[0066] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembly coating in Example 1, the difference in this example is that in step S2, the added Ca... 2+ The solution was 1000 μL of 37.5 mmol / L Ca. 2+ The solution preparation steps were the same as in Example 1. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZCaE3, the Pickering emulsion was named ZCaE3-PE, and the zein-based oleogel was named ZCaE3-O.

[0067] Reference Figure 1 After measurement, the particle size of the obtained ZCaE3 was 366.167±10.49nm, and the PDI<0.3.

[0068] Reference Figure 3 After measurement, the particle size distribution of the obtained ZCaE3-PE was found to be unimodal (~1μm).

[0069] Reference Figure 4 After testing, the obtained ZCaE3-O showed good extrudability.

[0070] Reference Figure 5 After measurement, the elastic modulus of ZCaE3-O was found to be 10. 4 ~10 5 Pa.

[0071] Reference Figure 6 After testing, the peroxide value of the obtained ZCaE3-O was 0.53 meq / kg, and the thiobarbituric acid value was 0.0071 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0072] Example 4

[0073] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembly coating in Example 1, the difference in this example is that in step S2, the added Ca... 2+ The solution is 1000 μL of 50 mmol / L Ca 2+ The solution preparation steps were the same as in Example 1. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZCaE5, the Pickering emulsion was named ZCaE5-PE, and the zein-based oleogel was named ZCaE5-O.

[0074] Reference Figure 1 After measurement, the particle size of the obtained ZCaE5 was 361.43±3.76nm, and the PDI<0.3.

[0075] Reference Figure 3 After measurement, the particle size distribution of the obtained ZCaE5-PE was found to be multi-peaked (main peak ~100μm, small peak ~1μm).

[0076] Reference Figure 4 After testing, the obtained ZCaE5-O showed good extrudability.

[0077] Reference Figure 5 After testing, the elastic modulus of ZCaE5-O was determined to be 10. 4 ~10 5 Pa.

[0078] Reference Figure 6After testing, the peroxide value of the obtained ZCaE5-O was 0.48 meq / kg, and the thiobarbituric acid value was 0.0068 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0079] Example 5

[0080] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembled coating in Example 1, the difference in this example is that in step S2, 1000 μL of 50 mmol / L EGCG solution (the resulting solution is named ZE) is added first, followed by 1000 μL of 12.5 mmol / L Ca. 2+ The solution preparation steps were the same as in Example 1. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZECa1, the Pickering emulsion was named ZECa1-PE, and the zein-based oleogel was named ZECa1-O.

[0081] Reference Figure 2 After measurement, the particle size of the obtained ZECa1 was 347.13±6.47nm, and the PDI<0.3.

[0082] Reference Figure 3 After measurement, the particle size distribution of ZECa1-PE was found to be unimodal (~1 μm).

[0083] Reference Figure 4 After testing, the obtained ZECa1-O showed good extrudability.

[0084] Reference Figure 5 After measurement, the elastic modulus of ZECa1-O was found to be 10. 4 ~10 5 Pa.

[0085] Reference Figure 6 After testing, the peroxide value of the obtained ZECa1-O was 0.54 meq / kg, and the thiobarbituric acid value was 0.007 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0086] Example 6

[0087] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembly coating in Example 5, the difference in this example is that in step S2, the added Ca... 2+ The solution is 1000 μL of 25 mmol / L Ca 2+The solution preparation steps were the same as in Example 5. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZECa2, the Pickering emulsion was named ZECa2-PE, and the zein-based oleogel was named ZECa2-O.

[0088] Reference Figure 2 After measurement, the particle size of the obtained ZECa2 was 356.50±3.26nm, and the PDI<0.3.

[0089] Reference Figure 3 After measurement, the particle size distribution of ZECa2-PE was found to be multi-peaked (main peak ~1μm, small peak ~100μm).

[0090] Reference Figure 4 After testing, the obtained ZECa2-O showed good extrudability.

[0091] Reference Figure 5 After measurement, the elastic modulus of ZECa2-O was found to be 10. 4 ~10 5 Pa.

[0092] Reference Figure 6 After testing, the peroxide value of the obtained ZECa2-O was 0.53 meq / kg, and the thiobarbituric acid value was 0.007 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0093] Example 7

[0094] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembly coating in Example 5, the difference in this example is that in step S2, the added Ca... 2+ The solution was 1000 μL of 37.5 mmol / L Ca. 2+ The solution preparation steps were the same as in Example 5. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZECa3, the Pickering emulsion was named ZECa3-PE, and the zein-based oleogel was named ZECa3-O.

[0095] Reference Figure 2 After measurement, the particle size of the obtained ZECa3 was 356.57±4.16nm, and the PDI<0.3.

[0096] Reference Figure 3 After measurement, the particle size distribution of ZECa3-PE was found to be multi-peaked (main peak ~100μm, small peak ~1μm).

[0097] Reference Figure 4 After testing, the obtained ZECa3-O showed good extrudability.

[0098] Reference Figure 5 After measurement, the elastic modulus of ZECa3-O was found to be 10. 4 ~10 5 Pa.

[0099] Reference Figure 6 After testing, the peroxide value of the obtained ZECa3-O was 0.53 meq / kg, and the thiobarbituric acid value was 0.0066 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0100] Example 8

[0101] Compared with the preparation method of zein-based oleogel based on polyphenol self-assembly coating in Example 5, the difference in this example is that in step S2, the added Ca... 2+ The solution is 1000 μL of 50 mmol / L Ca 2+ The solution preparation steps were the same as in Example 5. The resulting polyphenol self-assembled coating-coated zein composite particle dispersion was named ZECa5, the Pickering emulsion was named ZECa5-PE, and the zein-based oleogel was named ZECa5-O.

[0102] Reference Figure 2 After measurement, the particle size of the obtained ZECa5 was 361.43±10.02nm, and the PDI<0.3.

[0103] Reference Figure 3 After measurement, the particle size distribution of ZECa5-PE was found to be multi-peaked (main peak ~100μm, small peak ~10μm).

[0104] Reference Figure 4 After testing, the obtained ZECa5-O showed good extrudability.

[0105] Reference Figure 5 After testing, the elastic modulus of ZECa5-O was determined to be 10. 4 ~10 5 Pa.

[0106] Reference Figure 6 After testing, the peroxide value of the obtained ZECa5-O was 0.52 meq / kg, and the thiobarbituric acid value was 0.0065 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil.

[0107] Comparative Example 1

[0108] A method for preparing zein-based oleogloss includes the following steps:

[0109] S1. Weigh 2.0g of zein powder, add 100mL of 80% (V / V) ethanol-water solution, stir magnetically for 2h until completely dissolved, store the resulting solution at 4℃ for 10h, adjust the pH of the solution to 10, slowly add an equal volume of 10mmol / L Tris buffer under magnetic stirring, and then remove ethanol and some water by magnetic stirring at 40℃ to obtain a 2wt% zein dispersion.

[0110] S2. Mix the zein dispersion obtained in step S1 with corn oil and perform ultrasonic cell disruption treatment to obtain Pickering emulsion, named Z-PE; the ultrasonic cell disruption parameters are set as follows: 600W, 3s on, 3s off, working for 12min; the obtained Pickering emulsion is placed in a fume hood in the dark and dried in cold air for 24h to remove moisture, and solid fat is obtained.

[0111] S3. The solid fat obtained in step S2 is subjected to high-speed dispersion treatment at 10,000 rpm for 1 min to obtain zein-based oleogel, named ZO.

[0112] Reference Figure 3 The particle size distribution of the obtained Z-PE was determined to be unimodal (main peak ~1μm). However, compared with the bimodal distribution in Examples 1-8, Comparative Example 1 showed a unimodal distribution, indicating that the polyphenol self-assembled coating enhanced the bridging or flocculation of the emulsion, which to some extent benefited the stability of the emulsion.

[0113] Reference Figure 4 The obtained ZO was found to have good extrudability. However, compared with Examples 1-8, Comparative Example 1 showed oil leakage, indicating that the polyphenol self-assembled coating in Examples 1-8 can enhance the network stability of zein-based oleogels and prevent oil leakage.

[0114] Reference Figure 5 After measurement, the elastic modulus of ZO was found to be 10. 4 ~10 5 Pa. However, compared with Examples 1-8, Comparative Example 1 has the smallest storage modulus, indicating that the polyphenol self-assembled coating in Examples 1-8 can enhance the strength and deformation resistance of zein-based oleogels.

[0115] Reference Figure 6The obtained ZO was measured to have a peroxide value of 0.57 meq / kg and a thiobarbituric acid value of 0.0075 mg malondialdehyde / kg. Both the peroxide value and the thiobarbituric acid value were lower than those of bulk oil. However, compared with Examples 1-8, Comparative Example 1 had a higher peroxide value and a higher thiobarbituric acid value, indicating that the polyphenol self-assembled coating in Examples 1-8 can enhance the oxidative stability of zein oleoresin oil gel.

[0116] In Examples 1-8, due to Ca 2+ Concentration differences and Ca 2+ The performance of the zein-based oleogels based on polyphenol self-assembled coatings varied depending on the order of EGCG addition. The zein-based oleogel with the polyphenol self-assembled coating prepared in Example 8 exhibited the best overall performance, with an elastic modulus of 10⁴–10⁵ Pa, a peroxide value of 0.52 meq / kg, and a thiobarbituric acid value of 0.0065 mg malondialdehyde / kg. This was not only superior to the comparative example but also showed better performance across all examples. Other examples exhibited slightly lower performance in some aspects. For instance, Example 2 had the best elastic modulus but a high thiobarbituric acid value, while Example 4 had the lowest peroxide value but a poor elastic modulus. Example 8, on the other hand, not only had the lowest thiobarbituric acid value but also good elastic modulus and peroxide value. (Note: Ca...) 2+ Concentration and Ca 2+ The order of EGCG addition is crucial for improving the performance of zein-based oleogels with polyphenol self-assembly coatings.

[0117] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions or alterations can be made to these embodiments without departing from the principles and spirit of this application, and the technical solutions resulting from such changes, modifications, substitutions or alterations will all fall within the protection scope of this application.

Claims

1. A process for the preparation of a zein-based oleogel based on self-assembly of polyphenols, characterized in that, comprising the following steps: S1. dissolving zein in an ethanol-water solution, magnetically stirring for 2h until completely dissolved, the volume ratio of the ethanol-water solution is 80% V / V, storing in an environment of 2-8℃ for 7-12h, adjusting the pH value to 10 for pretreatment, adding a tris-hydroxymethyl aminomethane buffer and mixing, heating and stirring at 30-50℃ to remove ethanol, and preparing a zein dispersion; S2. adding epigallocatechin gallate to the zein dispersion prepared in step S1, and then adding 50mmol / L Ca2+ to prepare a composite particle dispersion; S3. mixing the composite particle dispersion with corn oil, performing ultrasonic cell disruption treatment to prepare a Pickering emulsion, and obtaining solid fat after light-shielded cold air drying for 18-30h; S4. dispersing the solid fat obtained in S3 to prepare a zein-based oil gel based on a polyphenol self-assembled coating; the amount ratio of the zein, 50mmol / L Ca2+ and the epigallocatechin gallate is 2g:0.05mmol:0.05mmol; step S1 further comprises adding a tris-hydroxymethyl aminomethane buffer and mixing before removing ethanol; step S2 is performed under stirring at a rotation speed of 1000-2000rpm; the zein-based oil gel based on a polyphenol self-assembled coating has an elastic modulus of 104-105Pa; the zein-based oil gel based on a polyphenol self-assembled coating has a peroxide value of 0.48-0.53meq / kg, and a thiobarbituric acid value of 0.0064-0.0068mg malondialdehyde / kg.

2. A zein-based oil gel based on a polyphenol self-assembled coating prepared by the method of claim 1, or the use of the zein-based oil gel based on a polyphenol self-assembled coating of claim 1 in the preparation of a solid or semi-solid food.

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