A purified double modified yeast protein, a heat-induced gel and preparation and use thereof

Abstract

The present application belongs to the technical field of modified yeast protein, and particularly relates to a double modified yeast protein purification product, a heat-induced gel and preparation and application thereof. The solubility of the double modified yeast protein purification product is greater than 15.00%, the turbidity is less than 1.70, the particle size is less than 1500.00 nm, the Zeta potential is less than -47.00 mV, and the succinylated degree is greater than 20.00%. The double modified yeast protein purification product is obtained by mixing yeast protein powder suspension with a pH of 7.0-11.0 and succinic anhydride at a dry matter mass ratio of 0.1:1-0.5:1, then performing succinylation reaction, ultrasonic treatment under a ultrasonic power of 200-600 W, and dialysis. The present application promotes specific conformational changes and interactions of modified yeast protein molecules in the double modified yeast protein purification product by controlled heat-induced technology, and a double modified yeast protein heat-induced gel product with good gel performance, transparency, water holding capacity and gel strength is prepared.

Description

Technical Field

[0001] This invention belongs to the field of modified yeast protein technology, specifically relating to a purified product of a dual-modified yeast protein, a heat-induced gel, and its preparation and application. Background Technology

[0002] In recent years, yeast protein, as an emerging functional protein ingredient, has shown strong market growth potential in the food and beverage, sports nutrition, and functional food sectors due to its unique nutritional advantages and sustainable properties. With the surge in consumer demand for plant-based and clean-label products, and the intensifying global supply-demand imbalance of protein resources, yeast protein, with its characteristics of "high biological value, low allergenicity, and complete nutrition," is regarded as an important supplement to traditional animal protein and traditional soy protein.

[0003] Yeast protein powder is made from brewer's yeast fermentation, centrifugation to remove nucleic acids, evaporation concentration, and spray drying. Although yeast protein powder shows great market potential due to its nutritional and sustainability advantages, the mainstream production process of currently commercially available products generally includes a long-term high-temperature sterilization process. This key step, to some extent, results in "denatured yeast protein," whose functional properties are significantly limited, specifically manifested as poor solubility and lack of gel-forming ability. These functional defects directly restrict the expansion of yeast protein applications in scenarios with high requirements for solubility and texture, such as high-protein beverages, protein alternatives, and gel-like foods.

[0004] Chinese patent application CN115536864A discloses a method for preparing a stable succinylation-synergistic ultrasound-modified ovalbumin nanoemulsion. However, although this patent uses a combination of succinylation and ultrasound, the raw material it processes is ovalbumin. Furthermore, because this patent utilizes a "freeze-drying followed by ultrasound" process route, it has the following key defects when applied to yeast protein, making it impossible to achieve the dual modification effect of this application:

[0005] This patent employs a step-by-step process of "succinylation → dialysis drying → reconstitution → sonication." This multi-phase transition (solution → solid → solution) leads to multiple alterations in the protein's native structure. During freeze-drying, ice crystal formation and dehydration cause irreversible protein aggregation, forming insoluble aggregates. The freeze-drying process following succinylation reduces protein solubility after reconstitution, and the reconstitution effect also affects the uniformity of protein dispersion, thus reducing the effectiveness of subsequent sonication. Furthermore, the multi-step process increases time and energy consumption, resulting in low energy efficiency. The drying and reconstitution processes also increase process complexity and cost. Summary of the Invention

[0006] The problem with the existing technology is:

[0007] (1) Functional limitations of single modification: Taking succinylation as an example, its essence of improving solubility by introducing negative charge is "charge repulsion to counteract hydrophobic aggregation". However, excessive increase in charge density will lead to excessive electrostatic repulsion between molecules, which will destroy the "weak cross-linking balance" required for subsequent gel network construction. At this time, protein molecules cannot be arranged in an orderly manner due to strong repulsion, and the water-holding capacity and elasticity of the gel will decrease significantly, resulting in the contradiction of "improved solubility but degraded gel properties". Similarly, although the particle size refinement of ultrasonic cavitation can optimize gel uniformity, its mechanical fragmentation may destroy the integrity of the protein tertiary structure, resulting in a reduction of sites where hydrogen bonds can be formed between molecules, which will weaken the cross-linking strength of the gel network.

[0008] (2) Insufficient adaptability of multi-technology synergy: Multi-technology synergy lacks system adaptability, and the superposition of processes leads to the accumulation of by-products and a decrease in product uniformity, which hinders industrial scale-up.

[0009] To address the aforementioned problems in the existing technology, this invention provides a purified product of dual-modified yeast protein, a heat-induced gel, its preparation, and its application. The specific technical solution is as follows:

[0010] Technical Solution 1: A dual-modified yeast protein purification product, characterized in that its solubility is greater than 15.00%, turbidity is less than 1.70, particle size is less than 1500.00 nm, zeta potential is less than -47.00 mV, and succinylation degree is greater than 20.00%, wherein the turbidity is the absorbance of the dual-modified yeast protein purification product measured at a wavelength of 600 nm.

[0011] Technical Solution 2: The dual-modified yeast protein purified according to Technical Solution 1, wherein the emulsifying activity is greater than 30.00 mg. 2 / g and emulsification stability greater than 60.00 min.

[0012] Technical Solution 3: The dual-modified yeast protein purified according to Technical Solution 1 or 2, wherein the solubility is 19.00-68.00%, and / or the turbidity is 0.16-1.70, and / or the particle size is 410.00-1335.00 nm, and / or the zeta potential is -62.00 to -47.00 mV, and / or the degree of succinylation is 28.00-97.00%, and / or the emulsifying activity is 30.00-36.00 mV. 2 / g, and / or emulsification stability of 60.00-62.00 min,

[0013] More preferably, the solubility is 63.00-68.00%, and / or the turbidity is 0.16-0.20, and / or the particle size is 410.00-430.00 nm, and / or the zeta potential is -62.00 to -58.00 mV, and / or the degree of succinylation is 93.00-97.00%, and / or the emulsifying activity is 33.00-36.00 mV. 2 / g.

[0014] Technical Solution 4: A purified dual-modified yeast protein according to any one of Technical Solutions 1-3, wherein the dual-modified yeast protein is prepared by a method comprising the following steps:

[0015] (1) A yeast protein powder suspension with a pH of 7.0-11.0 was mixed with succinic anhydride at a dry matter mass ratio of 0.1:1 to 0.5:1 and then subjected to succinylation reaction to obtain a succinylated yeast protein solution.

[0016] (2) The succinylated yeast protein solution was subjected to ultrasonic treatment at an ultrasonic power of 200-600 W to obtain a double-modified yeast protein solution.

[0017] (3) The double-modified yeast protein solution was dialyzed to remove unreacted small molecule succinic anhydride and salt, yielding a purified double-modified yeast protein.

[0018] Optionally, the double-modified yeast protein purified in step (3) is dried to obtain a solid double-modified yeast protein purified.

[0019] Technical Solution 5: The dual-modified yeast protein purified according to any one of Technical Solutions 1-4, characterized in that, in step (4), the solid is in powder form.

[0020] In step (3), the dialysis is performed using a dialysis bag, wherein the molecular weight cutoff of the dialysis bag is 8000-14000 Da, and preferably, the dialysis time is 40-60 h.

[0021] In step (1), the dry matter mass ratio of succinic anhydride to yeast protein powder is 0.3:1-0.4:1, preferably 0.3:1-0.35:1.

[0022] And / or in step (1), the pH is 9-10, preferably 9-9.5.

[0023] And / or in step (2), the ultrasonic power is 400-500 W, preferably 400-450 W, more preferably, in step (2), the ultrasonic frequency is 19.5-20.5 kHz, and / or the total ultrasonic treatment time is 25-40 min, preferably, the ultrasonic treatment procedure is ultrasonic treatment for 1-4 s followed by a stop for 1-4 s.

[0024] Technical Solution 6: A method for preparing a purified yeast protein with dual modification as described in any one of technical solutions 1-5, characterized in that it includes the following steps:

[0025] (1) A yeast protein powder suspension with a pH of 7.0-11.0 was mixed with succinic anhydride at a dry matter mass ratio of 0.1:1 to 0.5:1 and then subjected to succinylation reaction to obtain a succinylated yeast protein solution.

[0026] (2) The succinylated yeast protein solution was subjected to ultrasonic treatment at an ultrasonic power of 200-600 W to obtain a double-modified yeast protein solution.

[0027] (3) The double-modified yeast protein solution was dialyzed to obtain a purified double-modified yeast protein.

[0028] Optionally, the double-modified yeast protein purified in step (3) is dried to obtain a solid double-modified yeast protein purified.

[0029] Technical Solution 7: According to the preparation method described in Technical Solution 6, in step (1), during the succinylation reaction, the pH of the reaction system is 7.0-11.0.

[0030] Preferably, the succinylation reaction conditions are as follows: mixing at 20-25℃ for 2-4 h, followed by an ice bath for 5-20 min, and then adjusting the pH to 7.0±0.1 with an acid solution to terminate the succinylation reaction.

[0031] More preferably, the acid solution is an HCl solution with a concentration of 0.7-1.5 mol / L.

[0032] Technical Solution 8: According to the preparation method described in Technical Solution 6 or 7, in step (1), before mixing the yeast protein powder suspension with the succinic anhydride, the method further includes: mixing the yeast protein powder suspension at a mixing temperature of 20-25℃ for 1-3 hours to hydrate it.

[0033] Technical Solution 9: The preparation method according to any one of Technical Solutions 6-8, wherein in step (1), the concentration of the yeast protein powder suspension is 10-30 mg / mL.

[0034] Technical Solution 10: The preparation method according to any one of Technical Solutions 6-9, wherein in step (1), the pH of the yeast protein powder suspension is adjusted by using an alkaline solution.

[0035] Technical Solution 11: The preparation method according to any one of Technical Solutions 6-10, wherein the alkaline solution is a 0.7-1.5 mol / L NaOH solution.

[0036] Technical Solution 12: The preparation method according to any one of Technical Solutions 6-11, wherein in step (3), the drying is freeze drying, preferably, the freeze drying time is 40-60h and / or the freeze drying temperature is -45℃ to -55℃.

[0037] Technical Solution 13: A dual-modified yeast protein purified product, characterized in that it is prepared by any one of the preparation methods in Technical Solutions 6-12.

[0038] Technical Solution 14: The application of the dual-modified yeast protein purified product as described in any one of Technical Solutions 1-5 or the dual-modified yeast protein purified product as described in Technical Solution 13 in food, wherein the food includes one or more of the following: condiments, dairy products, baked goods, protein drinks, simulated meat products, and gel-based foods.

[0039] Technical Solution 15: A dual-modified yeast protein thermally induced gel, characterized in that it is prepared by the dual-modified yeast protein purified product described in any one of Technical Solutions 1-5 or the dual-modified yeast protein purified product described in Technical Solution 13.

[0040] Technical Solution 16: The dual-modified yeast protein heat-induced gel according to Technical Solution 15, wherein the light transmittance is 4.00-33.00, and / or the water retention is 75.00-99.90, and / or the hardness is 23.00-44.00, and / or the elasticity is 0.45-0.73, and / or the chewiness is 7.10-36.00, and / or the cohesion is 0.65-1.16.

[0041] Preferably, the light transmittance is 10.00-33.00, and / or the water retention is 90.00-99.90, and / or the hardness is 35.00-44.00, and / or the elasticity is 0.65-0.73, and / or the chewiness is 17.00-36.00, and / or the cohesion is 0.70-1.16.

[0042] More preferably, the light transmittance is 30.00-33.00, and / or the water retention is 98.00-99.90, and / or the hardness is 42.00-44.00, and / or the elasticity is 0.70-0.73, and / or the chewiness is 30.00-36.00, and / or the cohesion is 1.00-1.16.

[0043] Technical Solution 17: A method for preparing the dual-modified yeast protein thermally induced gel described in Technical Solution 15 or 16, characterized in that it includes the following steps: mixing the dual-modified yeast protein purified product described in any one of Technical Solutions 1-3 with water to obtain a mixed solution, heating the mixed solution and then cooling it to obtain the dual-modified yeast protein thermally induced gel.

[0044] Technical Solution 18: According to the preparation method described in Technical Solution 17, the concentration of the mixed solution is 5-20 mg / mL, preferably, the concentration of the mixed solution is 10-15 mg / mL, and / or the mixing speed is 300-400 r / min, and / or the mixing time is 1-4 h.

[0045] Technical Solution 19: According to the preparation method described in Technical Solution 17 or 18, before heating the mixed solution, the mixed solution is further subjected to standing, preferably for 12-24 hours and at a standing temperature of 4-25°C.

[0046] Technical Solution 20: The preparation method according to any one of Technical Solutions 17-19, wherein the heating is water bath heating, wherein the water bath heating temperature is 80-100℃ and / or the water bath heating time is 20-40 min.

[0047] Technical Solution 21: The preparation method according to any one of technical solutions 17-20 is characterized in that the cooling is ice-water bath cooling, wherein the ice-water bath temperature is 0-4℃ and / or the ice-water bath time is 10-15min.

[0048] Technical Solution 22: A dual-modified yeast protein thermally induced gel, characterized in that it is prepared by any one of the preparation methods in Technical Solutions 17-21.

[0049] Technical Solution 23: The application of the dual-modified yeast protein thermally induced gel described in any one of Technical Solution 15 or 16, or Technical Solution 21, in food, wherein the food includes one or more of the following: simulated meat products, cheese substitutes, puddings, and edible films.

[0050] The beneficial effects of this invention are as follows: This invention introduces a negative charge (-COO⁻ group) through succinylation, enhancing the hydrophilicity of the protein and the electrostatic repulsion between molecules, making the molecular structure in solution more loose and laying the charge foundation for gel network construction. Furthermore, this technology utilizes the ultrasonic cavitation effect to refine the protein particle size and optimize the uniformity of the gel network. That is, through a dual modification method of "chemical modification + physical treatment," synergistic regulation at the molecular level (charge introduction) and the macroscopic structural level (network reconstruction) is achieved, resulting in a dual-modified yeast protein purified product with a smaller particle size, higher net negative charge, higher degree of succinylation, higher solution colloidal stability, lower turbidity, and higher solubility. Further, this invention treats the dual-modified yeast protein purified product with controlled thermal induction technology to induce specific conformational changes and interactions in the modified yeast protein molecules, resulting in a dual-modified yeast protein thermally induced gel product with good gel performance, higher transparency, better water retention, and greater gel strength. Attached Figure Description

[0051] Figure 1 The images show the dissolution effect of the double-modified yeast protein powder prepared in Examples 1-5.

[0052] Figure 2 The solubility index of the double-modified yeast protein powder prepared in Examples 1-5 is used.

[0053] Figure 3 The turbidity index of the double-modified yeast protein powder prepared in Examples 1-5 is used.

[0054] Figure 4 The particle size index of the double-modified yeast protein powder prepared in Examples 1-5 is as follows.

[0055] Figure 5 The Zeta potential index of the double-modified yeast protein powder prepared in Examples 1-5.

[0056] Figure 6 The degree of succinylation of the double-modified yeast protein powder prepared in Examples 1-5 is used as an indicator.

[0057] Figure 7 The dissolution effect diagrams are shown for the double-modified yeast protein powders prepared in Examples 6-10.

[0058] Figure 8 The solubility index of the double-modified yeast protein powder prepared in Examples 6-10 is shown.

[0059] Figure 9 The turbidity index of the double-modified yeast protein powder prepared in Examples 6-10 is shown.

[0060] Figure 10The particle size index of the double-modified yeast protein powder prepared in Examples 6-10 is shown.

[0061] Figure 11 The Zeta potential index of the double-modified yeast protein powder prepared in Examples 6-10.

[0062] Figure 12 The degree of succinylation of the double-modified yeast protein powder prepared in Examples 6-10 is used as an indicator.

[0063] Figure 13 The images show the dissolution effect of the double-modified yeast protein powder prepared in Examples 11-15.

[0064] Figure 14 The solubility index of the double-modified yeast protein powder was obtained in Examples 11-15.

[0065] Figure 15 The turbidity index of the double-modified yeast protein powder was obtained in Examples 11-15.

[0066] Figure 16 The particle size index of the double-modified yeast protein powder was obtained in Examples 11-15.

[0067] Figure 17 The Zeta potential index of the double-modified yeast protein powder was obtained in Examples 11-15.

[0068] Figure 18 The diagram shows the dissolution effect of the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17.

[0069] Figure 19 The solubility indices of the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17 are as follows.

[0070] Figure 20 The particle size parameters of the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17 are as follows.

[0071] Figure 21 The emulsifying activity (EAI) and emulsifying stability (ESI) indices of the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17 were analyzed.

[0072] Figure 22 The images show the gelation effects of the control samples prepared in Examples 18 and 19, and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22.

[0073] Figure 23 The transmittance index is used for the control samples prepared in Examples 18 and 19 and the double-modified yeast protein heat-induced gels prepared in Examples 20-22.

[0074] Figure 24 The water-holding capacity index is used for the control samples prepared in Examples 18 and 19 and the double-modified yeast protein heat-induced gels prepared in Examples 20-22.

[0075] Figure 25 The texture-hardness / elasticity indices of the control samples prepared in Examples 18 and 19 and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22 are used as reference samples.

[0076] Figure 26 The texture-chewability / cohesiveness indexes of the control samples prepared in Examples 18 and 19 and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22. Detailed Implementation

[0077] This invention introduces negatively charged groups onto yeast protein molecules through a succinylation reaction. The objectives are: ① to significantly enhance the hydrophilicity of the protein, fundamentally improving its water solubility; ② to enhance the electrostatic repulsion between protein molecules, effectively preventing undesirable aggregation and laying the necessary foundation for the subsequent construction of an ordered and stable gel network based on charge interactions. Building upon succinylation modification, the strong cavitation effect generated by high-energy ultrasound is utilized. This process effectively breaks down large molecular aggregates, refines protein particle size, and improves its dispersion uniformity. The reduction in particle size and the improvement in homogeneity directly optimize the rheological properties of the gel precursor solution, creating favorable conditions for the formation of a denser and more uniform three-dimensional gel network structure. After the synergistic modification of succinylation and ultrasound treatment, controlled thermal induction technology is used to induce specific conformational changes and interactions (such as hydrophobic interactions and hydrogen bonding) in the modified protein molecules, achieving the transformation from sol to gel, thereby preparing a functional yeast protein gel product with ideal textural properties.

[0078] This invention addresses the poor solubility of yeast proteins through succinylation, which also provides the charge-driven force for constructing yeast protein gels. Ultrasonic treatment optimizes the microscopic uniformity of the yeast protein gel matrix. Finally, thermal induction provides a mature and controllable method for achieving yeast protein gel network formation. The synergistic effect of these three methods systematically overcomes the functional defects of denatured yeast proteins, significantly expanding their application potential in high-end foods (such as simulated meat products, cheese substitutes, puddings, and edible films).

[0079] To better understand the above technical solutions, the technical solutions of the present invention will be clearly and completely explained below in conjunction with specific embodiments. It should be noted that the content of the specific embodiments is only a specific implementation and explanation of the technical solutions of the present invention, and should not be construed as a limitation on the scope of protection of the present invention.

[0080] Terminology Explanation

[0081] Protein acylation is a functional modification process in which protein molecules are covalently bonded to acyl groups (such as succinyl or acetyl groups). Its core involves the covalent linkage between an acyl donor (such as succinic anhydride or acetic anhydride) and an amino acid residue containing active hydrogen in the protein molecule (mainly the ε-amino group of lysine, the N-terminal α-amino group, or the thiol group of cysteine). Protein acylation typically occurs under neutral or weakly alkaline conditions and can be accomplished through chemical catalysis (e.g., base-promoted acyl transfer) or enzymatic processes (e.g., acyltransferase-mediated). The acyl donor releases a positive acyl ion upon hydrolysis or enzymatic digestion, which binds to the active hydrogen of the protein residue, removing a water molecule to form a stable amide bond (-CO-NH-). This process introduces specific acyl side chains (such as the long carbon chain of succinyl groups) into the protein, altering its charge state (e.g., increased negative charge), spatial conformation, or intermolecular interactions, thereby regulating the protein's solubility, gelation properties, and other functional characteristics. It is widely used in protein functional modification in the food and pharmaceutical industries.

[0082] Ultrasonic processing, also known as ultrasonic cavitation, refers to a unique physical phenomenon caused by the periodic alternating positive and negative pressure waves generated when high-intensity ultrasound propagates in a liquid medium. In the negative pressure (rarely populated) phase of the sound waves, liquid molecules are violently stretched. When the local pressure is lower than the liquid's saturated vapor pressure, dissolved micro-gas nuclei or weak points within the liquid rapidly expand and grow, forming tiny bubbles filled with vapor and gas (cavitation bubbles). Subsequently, in the positive pressure (compression) phase, these bubbles are rapidly compressed and violently collapse (implosion) within an extremely short time (microseconds). This collapse process is highly localized, instantly generating extreme conditions: extremely high local temperatures, high pressures, and intense shock waves and high-speed microjets. These extreme physical effects can effectively break up particles, disperse aggregates, promote chemical reactions, disrupt cell structure, or alter the conformation of biological macromolecules (such as proteins). In protein modification, this effect mainly utilizes its powerful mechanical force to refine protein particle size, improve solubility, and optimize gel network uniformity.

[0083] Thermally induced gelation of proteins refers to the process of molecular structural reorganization and cross-linking under heating conditions: when the temperature rises to a specific range (usually 70-90℃), the protein molecules undergo increased thermal motion, exposing the hydrophobic groups and reactive sites that were originally folded inside. Molecules attract and entangle with each other through hydrogen bonds, hydrophobic interactions, and disulfide bonds, gradually forming a continuous three-dimensional network structure that encapsulates water molecules, ultimately transforming from a liquid state into a solid gel with certain elasticity and water-holding capacity. This gelation process is highly efficient, controllable, and universal, and is widely applicable to improving the texture and flavor carrying capacity of dairy products, plant-based meat, and other foods.

[0084] In some specific embodiments, the present invention provides a method for preparing dual-modified yeast protein, comprising the following steps:

[0085] (1) A yeast protein powder suspension with a pH of 7.0-11.0 was mixed with succinic anhydride at a dry matter mass ratio of 0.1:1 to 0.5:1 and then subjected to succinylation reaction to obtain a succinylated yeast protein solution.

[0086] (2) The succinylated yeast protein solution was subjected to ultrasonic treatment at an ultrasonic power of 200-600 W to obtain a double-modified yeast protein solution.

[0087] (3) The double-modified yeast protein solution was dialyzed to remove unreacted small molecule succinic anhydride and salt, yielding a purified double-modified yeast protein.

[0088] Optionally, the double-modified yeast protein purified in step (3) is dried to obtain a solid double-modified yeast protein purified.

[0089] Preferably, in some specific embodiments, the dry matter mass ratio of succinic anhydride to yeast protein powder in step (1) can be 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1 or 0.5:1, or a dry matter mass ratio of succinic anhydride to yeast protein powder within the numerical range formed by any two of the above specific values ​​as endpoints.

[0090] Preferably, in some specific embodiments, the pH of the yeast protein powder suspension in step (1) can be 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5 or 11.0, or the pH of the yeast protein powder suspension within the range of any two of the above specific values ​​as endpoints.

[0091] Preferably, in some specific embodiments, the ultrasonic power in step (2) can be 200W, 250W, 300W, 350W, 400W, 450W, 500W, 550W or 600W, or ultrasonic power within the range of any two of the above specific values ​​as endpoints.

[0092] Preferably, in some specific embodiments, the solubility of the dual-modified yeast protein purification product is 19.00-68.00%, and / or the turbidity is 0.16-1.70, and / or the particle size is 410.00-1335.00 nm, and / or the zeta potential is -62.00 to -47.00 mV, and / or the degree of succinylation is 28.00-97.00%, and / or the emulsifying activity is 30.00-36.00 mV. 2 / g.

[0093] More preferably, in some specific embodiments, the solubility of the dual-modified yeast protein purification product may be 19.00%, 20.00%, 21.00%, 22.00%, 23.00%, 24.00%, 25.00%, 26.00%, 27.00%, 28.00%, 29.00%, 30.00%, 31.00%, 32.00%, 33.00%, 34.00%, 35.00%, 36.00%, 37.00%, 38.00%, 39.00%, 40.00%, 41.00%, 42.00%, or 43.00%. Solubility of %, 44.00%, 45.00%, 46.00%, 47.00%, 48.00%, 49.00%, 50.00%, 51.00%, 52.00%, 53.00%, 54.00%, 55.00%, 56.00%, 57.00%, 58.00%, 59.00%, 60.00%, 61.00%, 62.00%, 63.00%, 64.00%, 65.00%, 66.00%, 67.00%, or 68.00%, or within the range of values ​​defined by any two of the above specific values ​​as endpoints.

[0094] More preferably, in some specific embodiments, the turbidity of the dual-modified yeast protein purification product may be 0.16, 0.17, 0.18, 0.19, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, or 1.70, or a turbidity within the numerical range formed by any two of the above specific values ​​as endpoints.

[0095] More preferably, in some specific embodiments, the particle size of the dual-modified yeast protein purification product may be 410.00 nm, 411.00 nm, 412.00 nm, 413.00 nm, 414.00 nm, 415.00 nm, 416.00 nm, 417.00 nm, 418.00 nm, 419.00 nm, 420.00 nm, 421.00 nm, 422.00 nm, 423.00 nm, 424.00 nm, 425.00 nm, 426.00 nm, 427.00 nm, or 428.00 nm. Particle sizes of 0 nm, 429.00 nm, 430.00 nm, 440.00 nm, 450.00 nm, 460.00 nm, 470.00 nm, 480.00 nm, 490.00 nm, 500.00 nm, 600.00 nm, 700.00 nm, 800.00 nm, 900.00 nm, 1000.00 nm, 1100.00 nm, 1220.00 nm, 1300.00 nm or 1335.00 nm, or within a numerical range defined by any two of the above specific values ​​as endpoints.

[0096] More preferably, in some specific embodiments, the zeta potential of the dual-modified yeast protein purification product can be [value missing].

[0097] -62.00mV, -61.00mV, -60.00mV, -59.00mV, -58.00mV, -57.00mV, -56.00mV, -55.00mV, -54.00mV, -53.00mV, -52.00mV, -51.00mV, -50.00mV, -49.00mV, -48.00mV or -47.00mV, or a Zeta potential within the range of any two of the above specific values ​​as endpoints.

[0098] More preferably, in some specific embodiments, the degree of succinylation of the dual-modified yeast protein purification product can be 28.00%, 29.00%, 30.00%, 31.00%, 32.00%, 33.00%, 34.00%, 35.00%, 36.00%, 37.00%, 38.00%, 39.00%, 40.00%, 41.00%, 42.00%, 43.00%, 44.00%, 45.00%, 46.00%, 47.00%, 48.00%, 49.00%, 50.00%, 51.00%, 52.00%, 53.00%, 54.00%, 55.00%, 56.00%, 57.00%, 58.00%, 59.00%, 60.00%, 61.00%, 62.00%. The degree of succinylation is 63.00%, 64.00%, 65.00%, 66.00%, 67.00%, 68.00%, 69.00%, 70.00%, 71.00%, 72.00%, 73.00%, 74.00%, 75.00%, 76.00%, 77.00%, 78.00%, 79.00%, 80.00%, 81.00%, 82.00%, 83.00%, 84.00%, 85.00%, 86.00%, 87.00%, 88.00%, 89.00%, 90.00%, 91.00%, 92.00%, 93.00%, 94.00%, 95.00%, 96.00%, or 97.00%, or falls within the range of values ​​defined by any two of the above specific values ​​as endpoints.

[0099] More preferably, in some specific embodiments, the emulsifying activity of the dual-modified yeast protein purification product can be 30.00, 30.10, 30.20, 30.30, 30.40, 30.50, 30.60, 30.70, 30.80, 30.90, 31.00, 31.10, 31.20, 31.30, 31.40, 31.50, 31.60, 31.70, 31.80, 31.90, 32.00, 32.10, 32.20, 32.30, 32.40, 32.50, 32.60, 32.70, 32.80, 32.90, 33.00, 33 The emulsifying activity is defined as 10, 33.20, 33.30, 33.40, 33.50, 33.60, 33.70, 33.80, 33.90, 34.00, 34.10, 34.20, 34.30, 34.40, 34.50, 34.60, 34.70, 34.80, 34.90, 35.00, 35.10, 35.20, 35.30, 35.40, 35.50, 35.60, 35.70, 35.80, 35.90, or 36.00, or falls within the numerical range defined by any two of the above specific values ​​as endpoints, wherein the unit of the emulsifying activity is m. 2 / g.

[0100] In some specific embodiments, the present invention also provides a dual-modified yeast protein thermally induced gel, characterized in that it is prepared by the dual-modified yeast protein purification product.

[0101] Preferably, in some specific embodiments, the dual-modified yeast protein heat-induced gel has a light transmittance of 4.00-33.00, and / or a water retention capacity of 75.00-99.90, and / or a hardness of 23.00-44.00, and / or an elasticity of 0.45-0.73, and / or a chewiness of 7.10-36.00, and / or a cohesiveness of 0.65-1.16.

[0102] Preferably, in some specific embodiments, the transmittance of the dual-modified yeast protein heat-induced gel can be 4.00, 5.00, 6.00, 7.00, 8.00, 9.00, 10.00, 11.00, 12.00, 13.00, 14.00, 15.00, 16.00, 17.00, 18.00, 19.00, 20.00, 21.00, 22.00, 23.00, 24.00, 25.00, 26.00, 27.00, 28.00, 29.00, 30.00, 31.00, 32.00, or 33.00, or a transmittance within a range of values ​​defined by any two of the above specific values ​​as endpoints.

[0103] Preferably, in some specific embodiments, the water-holding capacity of the dual-modified yeast protein heat-induced gel can be 75.00, 76.00, 77.00, 78.00, 79.00, 80.00, 81.00, 82.00, 83.00, 84.00, 85.00, 86.00, 87.00, 88.00, 89.00, 90.00, 91.00, 92.00, 93.00, 94.00, 95.00, 96.00, 97.00, 98.00, 99.00, or 99.90, or a water-holding capacity within the numerical range formed by any two of the above specific values ​​as endpoints.

[0104] Preferably, in some specific embodiments, the hardness of the dual-modified yeast protein heat-induced gel can be 23.00, 24.00, 25.00, 26.00, 27.00, 28.00, 29.00, 30.00, 31.00, 32.00, 33.00, 34.00, 35.00, 36.00, 37.00, 38.00, 39.00, 40.00, 41.00, 42.00, 43.00 or 44.00, or a hardness within the numerical range formed by any two of the above specific values ​​as endpoints.

[0105] Preferably, in some specific embodiments, the elasticity of the dual-modified yeast protein heat-induced gel may be 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, or 0.73, or an elasticity within the range of any two of the above specific values ​​as endpoints.

[0106] Preferably, in some specific embodiments, the chewiness of the dual-modified yeast protein heat-induced gel can be 7.10, 8.00, 9.00, 10.00, 11.00, 12.00, 13.00, 14.00, 15.00, 16.00, 17.00, 18.00, 19.00, 20.00, 21.00, 22.00, 23.00, 24.00, 25.00, 26.00, 27.00, 28.00, 29.00, 30.00, 31.00, 32.00, 33.00, 34.00, 35.00, or 36.00, or a chewiness within the range of any two of the above specific values ​​as endpoints.

[0107] Preferably, in some specific embodiments, the cohesiveness of the dual-modified yeast protein thermally induced gel can be 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, or 0. Cohesion of 90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, or 1.16, or within a numerical range defined by any two of the above specific values ​​as endpoints.

[0108] Preferably, in some specific embodiments, per 100g of yeast protein powder, the yeast protein powder contains 75-85g of protein, 5-15g of fat, 3-5g of carbohydrates, and 270-290mg of sodium.

[0109] Preferably, in some specific embodiments, the yeast protein powder used in the embodiments of the present invention can be obtained by conventional preparation methods in the art or can be commercially available. As long as the yeast protein powder obtained by conventional preparation methods in the art or commercially available has a protein content of 75-85g, fat 5-15g, carbohydrate 3-5g, and sodium 270-290mg per 100g of yeast protein powder, it can be used in the present invention.

[0110] To better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0111] Unless otherwise stated, all raw materials / reagents / instruments used in the embodiments of this invention are conventional commercially available products. The sources of information on the experimental materials used in this invention are shown in Table 1 below:

[0112]

[0113] Example 1: Preparation of dual-modified yeast protein powder

[0114] (1) Mix 2 g of yeast protein powder F80 with 100 mL of distilled water to obtain a yeast protein powder F80 suspension with a concentration of 20 mg / mL. Stir magnetically for 2 h at 25℃ and 400 r / min to ensure adequate hydration.

[0115] (2) Using a 1.0 mol / L NaOH solution, the pH of the yeast protein powder suspension obtained in step (1) was adjusted to 7.0. Then, according to the mass ratio of powdered succinic anhydride to the yeast protein powder F80 of 0.3:1, that is, based on the weight (2 g) of yeast protein powder F80, 0.6 g of powdered succinic anhydride was added to the yeast protein powder suspension to carry out the succinylation reaction. During the succinylation reaction, a 1.0 mol / L NaOH solution was used to stabilize the pH at 7.0. After magnetic stirring for 3 h at 25℃ and 400 r / min, the mixture was placed in an ice bath at 4℃ for 10 min. Then, the pH was adjusted to 7.0 using a 1.0 mol / L HCl solution to terminate the succinylation reaction and obtain a succinylated yeast protein solution.

[0116] (3) The succinylated yeast protein solution obtained in step (2) was subjected to ultrasonic treatment in an ice-water bath (4°C) using an ultrasonic cell disruptor (ultrasonic treatment frequency of 20kHz, pulse period of 2 seconds of ultrasonic treatment followed by 2 seconds of stop; ultrasonic power of 400W, ultrasonic time of 30 minutes, where ultrasonic time here includes ultrasonic stop time) to obtain a double-modified yeast protein solution.

[0117] (4) The double-modified yeast protein solution obtained in step (3) was dialyzed for 48 h at 4 °C using a dialysis bag with a molecular weight cutoff of 8000-14000 Da to remove unreacted small molecule succinic anhydride and salt. Then it was freeze-dried at -50 °C for 48 h to obtain double-modified yeast protein powder.

[0118] Example 2: Preparation of dual-modified yeast protein powder

[0119] The difference from Example 1 is that in step (2), the pH of the yeast protein powder suspension obtained in step (1) is adjusted to 8.0; and during the succinylation reaction, a 1.0 mol / L NaOH solution is used to stabilize the pH at 8.0, and after magnetic stirring at 25°C and 400 r / min for 3 h, the solution is placed in an ice bath at 4°C for 10 min, and then the pH is adjusted to 7.0 using a 1.0 mol / L HCl solution to terminate the succinylation reaction and obtain a succinylated yeast protein solution.

[0120] Example 3: Preparation of dual-modified yeast protein powder

[0121] The difference from Example 1 is that in step (2), the pH of the yeast protein powder suspension obtained in step (1) is adjusted to 9.0; and during the succinylation reaction, a 1.0 mol / L NaOH solution is used to stabilize the pH at 9.0, and after magnetic stirring at 25°C and 400 r / min for 3 h, the solution is placed in an ice bath at 4°C for 10 min, and then the pH is adjusted to 7.0 using a 1.0 mol / L HCl solution to terminate the succinylation reaction and obtain a succinylated yeast protein solution.

[0122] Example 4: Preparation of dual-modified yeast protein powder

[0123] The difference from Example 1 is that in step (2), the pH of the yeast protein powder suspension obtained in step (1) is adjusted to 10.0; and during the succinylation reaction, a 1.0 mol / L NaOH solution is used to stabilize the pH at 10.0, and after magnetic stirring at 25°C and 400 r / min for 3 h, the solution is placed in an ice bath at 4°C for 10 min, and then the pH is adjusted to 7.0 using a 1.0 mol / L HCl solution to terminate the succinylation reaction and obtain a succinylated yeast protein solution.

[0124] Example 5: Preparation of dual-modified yeast protein powder

[0125] The difference from Example 1 is that in step (2), the pH value of the yeast protein powder suspension obtained in step (1) is adjusted to 11.0; and during the succinylation reaction, a 1.0 mol / L NaOH solution is used to stabilize the pH at 11.0, and after magnetic stirring at 25°C and 400 r / min for 3 hours, the solution is placed in an ice bath at 4°C for 10 minutes. Then, the pH is adjusted to 7.0 using a 1.0 mol / L HCl solution to terminate the succinylation reaction and obtain a succinylated yeast protein solution.

[0126] Example 6: Preparation of dual-modified yeast protein powder

[0127] The difference from Example 3 is that in step (2), succinic anhydride is added to the yeast protein powder in a mass ratio of 0.1:1 to carry out the succinylation reaction.

[0128] Example 7: Preparation of dual-modified yeast protein powder

[0129] The difference from Example 3 is that in step (2), succinic anhydride is added to the yeast protein powder in a mass ratio of 0.2:1 to carry out the succinylation reaction.

[0130] Example 8: Preparation of dual-modified yeast protein powder

[0131] The difference from Example 3 is that in step (2), succinic anhydride is added to the yeast protein powder in a mass ratio of 0.3:1 to carry out the succinylation reaction.

[0132] Example 9: Preparation of Dually Modified Yeast Protein Powder

[0133] The difference from Example 3 is that in step (2), succinic anhydride is added to the yeast protein powder in a mass ratio of 0.4:1 to carry out the succinylation reaction.

[0134] Example 10: Preparation of dual-modified yeast protein powder

[0135] The difference from Example 3 is that in step (2), succinic anhydride is added to the yeast protein powder in a mass ratio of 0.5:1 to carry out the succinylation reaction.

[0136] Example 11 Preparation of dual-modified yeast protein powder

[0137] The difference from Example 8 is that in step (3), the ultrasonic power is 200W.

[0138] Example 12: Preparation of dual-modified yeast protein powder

[0139] The difference from Example 8 is that in step (3), the ultrasonic power is 300W.

[0140] Example 13 Preparation of dual-modified yeast protein powder

[0141] The difference from Example 8 is that in step (3), the ultrasonic power is 400W.

[0142] Example 14: Preparation of dual-modified yeast protein powder

[0143] The difference from Example 8 is that in step (3), the ultrasonic power is 500W.

[0144] Example 15: Preparation of Dually Modified Yeast Protein Powder

[0145] The difference from Example 8 is that in step (3), the ultrasonic power is 600W.

[0146] Example 16 Preparation of yeast protein powder that has undergone succinylation but has not been sonicated

[0147] The difference from Example 13 is that step (3) is omitted.

[0148] Example 17 Preparation of yeast protein powder that has been ultrasonically treated but not succinylated

[0149] The difference from Example 13 is that step (2) is omitted.

[0150] Example 18: Preparation of a control of a dual-modified yeast protein thermally induced gel that was neither succinylated nor sonicated.

[0151] 2 g of yeast protein powder F80 was mixed with 20 mL of distilled water and magnetically stirred at 25 °C and 400 r / min for 4 h to obtain a mixture with a concentration of 10 mg / mL. The mixture was then placed at 4 °C for 12 h to allow for full hydration. The hydrated mixture was then heated in a water bath at 90 °C for 30 min and then quickly transferred to an ice-water bath and treated at 0 °C for 10 min to obtain a control sample that was neither succinylated nor sonicated.

[0152] Example 19: Preparation of a control of a dual-modified yeast protein thermo-induced gel that has been sonicated but not succinylated.

[0153] 2 g of yeast protein powder (UYP) prepared in Example 17 was mixed and dissolved in 20 mL of distilled water. The mixture was then magnetically stirred at 25 °C and 400 r / min for 4 h to obtain a mixture with a concentration of 10 mg / mL. The mixture was then placed at 4 °C for 12 h to allow for full hydration. The hydrated mixture was then heated in a water bath at 90 °C for 30 min and then quickly transferred to an ice-water bath and treated at 0 °C for 10 min to obtain a control of the dual-modified yeast protein thermally induced gel treated only by ultrasound.

[0154] Example 20: Preparation of a dual-modified yeast protein thermo-induced gel

[0155] 2 g of the double-modified yeast protein powder (SUYP0.1) prepared in Example 6 was mixed and dissolved in 20 mL of distilled water. Then, the mixture was magnetically stirred at 25 °C and 400 r / min for 2 h to obtain a mixture with a concentration of 10 mg / mL. The mixture was then placed at 4 °C for 12 h to allow for sufficient hydration. The hydrated mixture was then heated in a water bath at 90 °C for 30 min and then quickly transferred to an ice-water bath and treated at 0 °C for 10 min to obtain a double-modified yeast protein thermo-induced gel.

[0156] Example 21 Preparation of dual-modified yeast protein thermo-induced gel

[0157] 2 g of the double-modified yeast protein powder (SUYP0.2) prepared in Example 7 was mixed and dissolved in 20 mL of distilled water. Then, the mixture was magnetically stirred at 25 °C and 400 r / min for 3 h to obtain a mixture with a concentration of 10 mg / mL. The mixture was then placed at 4 °C for 12 h to allow for sufficient hydration. The hydrated mixture was then heated in a water bath at 90 °C for 30 min and then quickly transferred to an ice-water bath and treated at 0 °C for 10 min to obtain a double-modified yeast protein thermally induced gel.

[0158] Example 22 Preparation of dual-modified yeast protein thermo-induced gel

[0159] 2 g of the double-modified yeast protein powder (SUYP0.3) prepared in Example 8 was mixed and dissolved in 20 mL of distilled water. Then, the mixture was magnetically stirred at 25 °C and 400 r / min for 4 h to obtain a mixture with a concentration of 10 mg / mL. The mixture was then placed at 4 °C for 12 h to allow for sufficient hydration. The hydrated mixture was then heated in a water bath at 90 °C for 30 min and then quickly transferred to an ice-water bath and treated at 0 °C for 10 min to obtain a double-modified yeast protein thermo-induced gel.

[0160] Evaluation method of technical effect of dual-modified yeast protein powder

[0161] 1. Protein solubility detection: Samples of the double-modified yeast protein powder prepared in Examples 1-15 and the yeast protein powder prepared in Examples 16 and 17 were taken respectively, and 5 mg of the sample was diluted with 1 mL of ultrapure water to a concentration of 5 mg / mL to obtain sample solutions. Then, the samples were centrifuged at 1000 r / min and 4 ℃ for 10 min to obtain supernatant. The protein concentration of the sample solutions and the supernatant was determined according to the biuret method. The specific steps were as follows: 1.5 g of copper sulfate pentahydrate and 6 g of potassium sodium tartrate (tetrahydrate) were weighed and dissolved in ultrapure water. 300 mL of 10% NaOH solution was added while stirring slowly. The volume was adjusted to 1000 mL with ultrapure water and stored at room temperature in the dark. Method for preparing the protein standard curve: Using 10 mg / mL bovine serum albumin as the standard protein solution, different protein solutions with concentration gradients of 0-10 mg / mL were prepared by adding ultrapure water. The protein solutions were mixed with biuret reagent at a ratio of 1:4, vortexed, and incubated at room temperature in the dark for 30 min. The absorbance (A540) was measured. The results are expressed as the average of three parallel samples. The standard curve was prepared by plotting protein concentration and absorbance on the x and y axes, respectively, as y = 0.0438x + 0.0007, R0. 2=0.9998. The protein concentration of the sample was determined as follows: 1 mL of sample solution was taken, 4 mL of biuret reagent was added, the mixture was shaken and incubated at room temperature in the dark for 30 min, and the absorbance was measured at 540 nm. The protein concentration of the sample was calculated according to the standard curve equation. The initial protein concentration (C0) and the protein concentration of the supernatant (C...) were obtained respectively. s And calculate the protein solubility according to the following formula 1:

[0162] ;

[0163] Where C0 (mg / mL) represents the initial concentration of protein, C s (mg / mL) represents the protein concentration in the supernatant.

[0164] 2. Test of colloidal stability of solution: Samples of the double-modified yeast protein powder prepared in Examples 1-15 and the yeast protein powder prepared in Examples 16 and 17 were taken respectively, and 20 mg of the sample was diluted with 1 mL of ultrapure water to a concentration of 20 mg / mL. The sample solutions were placed in transparent glass bottles and observed at room temperature (20-25℃). The state of the sample solutions was recorded by taking pictures at 0 h, 1 h and 10 h.

[0165] 3. Turbidity detection: Samples of the double-modified yeast protein powder prepared in Examples 1-15 and the yeast protein powder prepared in Examples 16 and 17 were taken respectively, and 2.5 mg of the sample was diluted with 1 mL of ultrapure water to a concentration of 2.5 mg / mL to obtain a sample solution. The solution was shaken and mixed for 10 s, and then the absorbance was measured at 600 nm to determine the turbidity.

[0166] 4. Detection of particle size and zeta potential: Samples of the double-modified yeast protein powder prepared in Examples 1-15 and the yeast protein powder prepared in Examples 16 and 17 were taken respectively, and 0.2 mg of the sample was diluted with 1 mL of ultrapure water to a concentration of 0.2 mg / mL to obtain sample solutions. Then, the particle size and zeta potential of the sample solutions were measured using a nanoparticle size potentiometer.

[0167] 5. Determination of Succinylation Degree: The degree of succinylation (DS) of yeast protein was determined using the ninhydrin method. The specific steps were as follows: 2 mL of the sample solution (1%, w / v) was mixed thoroughly with 2 mL of ninhydrin solution (2%, w / v), then heated in a boiling water bath for 10 min. The mixture was then removed and cooled to room temperature with ice water to obtain the reaction solution. 1 mL of the reaction solution was thoroughly mixed with 50 mL of potassium iodate solution (0.2%, w / v), and allowed to stand for 15 min. The absorbance of the solution at 570 nm was measured using a UV spectrophotometer, and the degree of succinylation was calculated according to the following formula 2:

[0168] ;

[0169] Where A0 represents the absorbance of the unsuccinylated sample solution, and A represents the absorbance of the succinylated sample solution.

[0170] The preparation method of the unsuccinylated sample solution is as follows: 2 g of yeast protein powder F80 is mixed with 100 mL of distilled water to obtain a yeast protein powder F80 suspension with a concentration of 20 mg / mL. The suspension is magnetically stirred at 25℃ and 400 r / min for 5 h, and then freeze-dried at -50℃ for 48 h to obtain yeast protein powder without double modification treatment. 0.02 g of the yeast protein powder is mixed with 2 mL of distilled water to obtain an unsuccinylated sample solution with a concentration of 1 mg / mL (i.e., 1%, w / v).

[0171] The preparation method of the succinylated sample solution is as follows: 0.02 g of the double-modified yeast protein powder obtained in Examples 1-15 is mixed with 2 mL of distilled water to obtain a succinylated sample solution with a concentration of 1 mg / mL (i.e., 1%, w / v).

[0172] 6. Detection of Emulsifying Activity (EAI) and Emulsifying Stability (ESI): Samples of the dual-modified yeast protein powder prepared in Examples 1-15 and the yeast protein powder prepared in Examples 16 and 17 were taken, and 5 mg of the sample was diluted with 1 mL of ultrapure water to a concentration of 5 mg / mL to obtain sample solutions. 2 mL of soybean oil was mixed with 6 mL of sample solutions and homogenized for 1 min at room temperature (20-25℃) and 15000 rpm to obtain an emulsion. Then, 50 μL of the emulsion was taken from the bottom and mixed with 5 mL of 0.1% sodium dodecyl sulfate (SDS) solution. The absorbance at 500 nm was immediately measured using a UV spectrophotometer (A0). After the emulsion for which the absorbance was measured was allowed to stand for 10 min, 50 μL of the emulsion was mixed with 5 mL of 0.1% sodium dodecyl sulfate (SDS) solution and the absorbance at 500 nm was measured (A0). t The blank was a 0.1% SDS solution; the emulsifying activity (EAI) and emulsifying stability (ESI) were calculated according to Formulas 3 and 4 below, respectively:

[0173] ;

[0174] Where C represents the protein concentration (g / mL), φ represents the oil volume fraction, and D represents the dilution factor.

[0175]

[0176] Where A0 represents the absorbance of the emulsion, A t The absorbance of the emulsion after standing for 10 minutes is expressed as Δ. t This represents the settling time.

[0177] Evaluation results of the technical effects of dual-modified yeast protein powder

[0178] It should be noted that YP in the technical effect evaluation results of the double-modified yeast protein powder below indicates yeast protein powder without double modification treatment. Its preparation method is as follows: 2 g of yeast protein powder F80 is mixed with 100 mL of distilled water to obtain a yeast protein powder F80 suspension with a concentration of 20 mg / mL. The suspension is magnetically stirred at 25℃ and 400 r / min for 5 h to fully hydrate it. Then, it is freeze-dried at -50℃ for 48 h to obtain yeast protein powder without double modification treatment.

[0179] 1. The solubility, turbidity, particle size, zeta potential, and degree of succinylation of the double-modified yeast protein powder prepared in Examples 1-5 are shown in Table 2 below. Figure 1-6 As shown:

[0180]

[0181] As shown in Table 2 and Figure 1-6 As shown in Table 2, N represents the number of experimental repetitions; Figure 1 The images show the solubility of the dual-modified yeast protein powder prepared in Examples 1-5. Figure 2 The solubility index of the dual-modified yeast protein powder prepared in Examples 1-5 is as follows: Figure 3 The turbidity index of the double-modified yeast protein powder prepared in Examples 1-5 is as follows: Figure 4 The particle size index of the double-modified yeast protein powder prepared in Examples 1-5 is as follows: Figure 5 The Zeta potential index of the dual-modified yeast protein powder prepared in Examples 1-5, Figure 6 The degree of succinylation of the double-modified yeast protein powder prepared in Examples 1-5 is used as an indicator. Figure 1-6 In the examples, YP represents unmodified yeast protein powder, and 7, 8, 9, 10, and 11 represent the dual-modified yeast protein powders prepared in Examples 1, 2, 3, 4, and 5, respectively. The results show that, compared to YP, the dual-modified yeast protein powders prepared in Examples 1-5 have lower particle size, higher net negative charge, and achieve a higher degree of succinylation. This results in higher solution colloidal stability, lower turbidity, and greater solubility in the dual-modified yeast protein powder dispersion. Furthermore, from... Figure 1As can be seen from Examples 1-5, the dual-modified yeast protein powder prepared in Example 3 has the best overall effect. It can be seen that under the condition of pH 9.0, the dual-modified yeast protein powder can have a lower particle size, a higher net negative charge, and a higher degree of succinylation, thereby giving the protein dispersion better solution colloidal stability, lower turbidity, and greater solubility.

[0182] 2. The solubility, turbidity, particle size, zeta potential, and degree of succinylation of the double-modified yeast protein powders prepared in Examples 6-10 are shown in Table 3 below. Figure 7-12 As shown:

[0183]

[0184] As shown in Table 3 and Figure 7-12 As shown in Table 3, N represents the number of experimental repetitions; Figure 7 The dissolution effect diagrams for the dual-modified yeast protein powders prepared in Examples 6-10 are shown. Figure 8 The solubility index of the dual-modified yeast protein powder prepared in Examples 6-10 is as follows: Figure 9 The turbidity index of the double-modified yeast protein powder prepared in Examples 6-10 Figure 10 The particle size index of the double-modified yeast protein powder prepared in Examples 6-10 is as follows: Figure 11 The Zeta potential index of the dual-modified yeast protein powder prepared in Examples 6-10 Figure 12 The degree of succinylation of the double-modified yeast protein powder prepared in Examples 6-10 is used as an indicator. Figure 7-12 In this context, YP represents yeast protein powder without dual modification treatment, and 0.1, 0.2, 0.3, 0.4 and 0.5 represent the dual-modified yeast protein powders prepared in Examples 6, 7, 8, 9 and 10, respectively.

[0185] The results showed that, compared to YP, the dual-modified yeast protein powder prepared in Examples 6-10 had a smaller particle size, a higher net negative charge, and achieved a higher degree of succinylation. This resulted in the dual-modified yeast protein powder dispersion exhibiting higher solution colloidal stability, lower turbidity, and greater solubility. Furthermore, from... Figure 2 As can be seen from Examples 6-10, the dual-modified yeast protein powder prepared in Example 8 has the best overall effect. It can be seen that under the condition that the mass ratio of succinic anhydride to yeast protein powder is 0.3:1, the dual-modified yeast protein powder can have a lower particle size, a higher net negative charge, and a higher degree of succinylation, thereby giving the protein dispersion better solution colloidal stability, lower turbidity, and greater solubility.

[0186] 3. The solubility, turbidity, particle size, and zeta potential of the dual-modified yeast protein powders prepared in Examples 11-15 are shown in Table 4 below. Figure 13-17 As shown:

[0187]

[0188] As shown in Table 4 and Figure 13-17 As shown in Table 4, N represents the number of experimental repetitions; Figure 13 The dissolution effect diagrams of the dual-modified yeast protein powder prepared in Examples 11-15 are shown. Figure 14 The solubility index of the dual-modified yeast protein powder prepared in Examples 11-15 is as follows: Figure 15 The turbidity index of the double-modified yeast protein powder prepared in Examples 11-15 is as follows: Figure 16 The particle size index of the double-modified yeast protein powder prepared in Examples 11-15 is as follows: Figure 17 The Zeta potential index of the dual-modified yeast protein powder was obtained in Examples 11-15. Figure 13-17 In this text, YP represents unmodified yeast protein powder, and 200W, 300W, 400W, 500W, and 600W correspond to the dual-modified yeast protein powders prepared in Examples 11, 12, 13, 14, and 15, respectively. The results show that, compared to YP, the dual-modified yeast protein powders prepared in Examples 11-15 have lower particle size and higher net negative charge, resulting in higher solution colloidal stability, lower turbidity, and greater solubility. Furthermore, from... Figure 3 As can be seen from Examples 11-15, the dual-modified yeast protein powder prepared in Example 13 has the best overall effect. It can be seen that under the condition of ultrasonic power of 400 W, the dual-modified yeast protein powder can have a lower particle size and a higher net negative charge, thereby giving the protein dispersion better solution colloidal stability, lower turbidity and greater solubility.

[0189] 4. The doubly modified yeast protein powder was prepared in Example 13, and the yeast was prepared in Examples 16 and 17.

[0190] The test results for the protein powder's solubility, particle size index, emulsifying activity (EAI), and emulsifying stability (ESI) are shown in Table 5 below. Figure 18-21 As shown:

[0191]

[0192] As shown in Table 5 and Figure 18-21 As shown in Table 5, N represents the number of experimental repetitions; Figure 18The dissolution effect diagrams are shown for the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17. Figure 19 The solubility indices of the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17, are as follows: Figure 20 The particle size index of the double-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17, are as follows: Figure 21 The emulsifying activity (EAI) and emulsifying stability (ESI) indices of the dual-modified yeast protein powder prepared in Example 13, and the yeast protein powder prepared in Examples 16 and 17, are described. Figure 18-21 In this context, YP represents yeast protein powder without dual modification treatment, and UYP, SYP, and SYP-U represent the yeast protein powder prepared in Example 16, the yeast protein powder prepared in Example 17, and the dual-modified yeast protein powder prepared in Example 13, respectively.

[0193] The results showed that, compared with YP, Example 16 (UYP) and Example 17 (SYP), the dual-modified yeast protein powder prepared in Example 13 (SYP-U) had the smallest particle size and the best solution stability, solubility and emulsification properties.

[0194] Evaluation of the technical effects of dual-modified yeast protein thermo-induced gel

[0195] 1. Measurement of transmittance: The yeast protein thermally induced gels prepared in Examples 18 and 19 and the double-modified yeast protein thermally induced gels prepared in Examples 20-22 were cut into cubes of length × width × height (1 cm × 1 cm × 2 cm) to obtain gel samples of Examples 18-22, and transferred to quartz cuvettes (optical path length of 1 cm). Then, the transmittance of the gel samples was measured at 600 nm using a UV spectrophotometer.

[0196] 2. Determination of water-holding capacity: 1.00 g of freshly prepared yeast protein thermally induced gels obtained in Examples 18 and 19, and the double-modified yeast protein thermally induced gels obtained in Examples 20-22 were placed in 10 mL centrifuge tubes and centrifuged at 4 °C and 10000 r / min for 30 min. The supernatant was discarded, and the surface of the hydrogel sample was carefully wiped dry with absorbent paper. The water-holding capacity (WHC) was calculated according to the following formula 5:

[0197] ;

[0198] Where m0 represents the mass of the blank centrifuge tube, m1 represents the mass of the centrifuge tube and gel sample before centrifugation, and m2 represents the mass of the centrifuge tube and gel sample after centrifugation.

[0199] 3. Determination of textural properties: Freshly prepared yeast protein thermally induced gels obtained in Examples 18 and 19, and double-modified yeast protein thermally induced gels obtained in Examples 20-22 were equilibrated at room temperature (25 °C) for 12 h, and then their textural properties were tested. The specific method for testing the textural properties was as follows: cylindrical gel samples of Examples 18-22 with a diameter of 1 cm and a height of 2 cm were tested using a texture analyzer TA-XTplus equipped with a P / 36R probe, and the parameters were set as follows: pre-test speed of 1 mm / s, mid-test speed of 1 mm / s, post-test speed of 5 mm / s, and compressibility of 50%.

[0200] Evaluation results of the technical effects of dual-modified yeast protein thermo-induced gel

[0201] 1. The test results of transmittance, water retention and textural properties of the dual-modified yeast protein heat-induced gels prepared in Examples 20-22 are shown in Table 6 below. Figure 22-26 As shown:

[0202]

[0203] As shown in Table 6 and Figure 22-26 As shown in Table 6, N represents the number of experimental repetitions; Figure 22 The gelation effect diagrams are shown for the control samples prepared in Examples 18 and 19, and the heat-induced gels of the double-modified yeast protein prepared in Examples 20-22. Figure 23 The transmittance of the control samples prepared in Examples 18 and 19, and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22, are also relevant indicators. Figure 24 The water-holding capacity of the control samples prepared in Examples 18 and 19, and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22, are also relevant indicators. Figure 25 The texture-hardness / elasticity indices of the control samples prepared in Examples 18 and 19, and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22 are as follows: Figure 26 The textural-chewability / cohesiveness indices of the control samples prepared in Examples 18 and 19 and the dual-modified yeast protein heat-induced gels prepared in Examples 20-22; Figure 22-26In the examples, YP represents the control sample prepared in Example 18 that was neither succinylated nor sonicated; UYP represents the control sample prepared in Example 19 that was only sonicated; SUYP0.1 represents the double-modified yeast protein thermally induced gel prepared in Example 20; SUYP0.2 represents the double-modified yeast protein thermally induced gel prepared in Example 21; and SUYP0.3 represents the double-modified yeast protein thermally induced gel prepared in Example 22. The results show that Examples 18 (YP) and 19 (UYP) could not form gels through thermal induction. The double-modified yeast protein thermally induced gels of Examples 20 (SUYP0.1), 21 (SUYP0.2), and 22 (SUYP0.3), which underwent succinylation-sonication dual modification, possessed certain gel properties. In Examples 20-22, the yeast protein gel samples with a higher degree of succinylation exhibited higher transparency, better water retention, and greater gel strength.

[0204] The above embodiments are only for further explanation and understanding of the technical solution of the present invention, and are not intended to limit the present invention. Any improvements made by those skilled in the art on this basis that do not highlight substantive features or make significant progress should fall within the protection scope of the present invention.

Claims

1. A method for preparing a dual-modified yeast protein thermo-induced gel, characterized in that, The process includes the following steps: mixing a solid, dual-modified yeast protein extract with water to obtain a mixed solution; heating the mixed solution and then cooling it to obtain a thermally induced gel of the dual-modified yeast protein; wherein the concentration of the dual-modified yeast protein extract in the mixed solution is 5-20 mg / mL; the heating is performed in a water bath at a temperature of 80-100°C for 20-40 minutes; and the preparation method of the solid, dual-modified yeast protein extract includes the following steps: (1) A yeast protein powder suspension with a pH of 8.5-9.5 was mixed with succinic anhydride at a dry matter mass ratio of 0.25:1 to 0.35:1 and then subjected to succinylation reaction to obtain a succinylated yeast protein solution. (2) The succinylated yeast protein solution is subjected to ultrasonic treatment at an ultrasonic power of 350-450 W to obtain a double-modified yeast protein solution, wherein the total ultrasonic treatment time is 30-40 min. (3) The double-modified yeast protein solution was dialyzed to remove unreacted small molecule succinic anhydride and salt, yielding a purified double-modified yeast protein. (4) After drying the double-modified yeast protein purified in step (3), a solid double-modified yeast protein purified is obtained, wherein the solid double-modified yeast protein purified has a solubility of 63.00-68.00%, a turbidity of 0.16-0.20, a particle size of 410.00-430.00 nm, a zeta potential of -62.00 to -58.00 mV, and a succinylation degree of 93.00-97.00%.

2. The preparation method according to claim 1, wherein, The emulsifying activity of the solid, dual-modified yeast protein purification product was 33.00-36.00 mg / L. 2 / g.

3. The preparation method according to claim 1, wherein, In step (4), the solid state is in powder form; And / or in step (3), the dialysis is performed using a dialysis bag, wherein the molecular weight cutoff of the dialysis bag is 8000-14000 Da.

4. The preparation method according to claim 1, wherein, In step (2), the frequency of ultrasound is 19.5-20.5 kHz.

5. The preparation method according to claim 1, wherein, In step (1), the conditions for the succinylation reaction are: mixing at 20-25℃ for 2-4 h followed by an ice bath for 5-20 min, and then adjusting the pH to 7.0±0.1 with an acid solution to terminate the succinylation reaction.

6. The preparation method according to claim 1, wherein, In step (1), before mixing the yeast protein powder suspension with the succinic anhydride, the process further includes mixing the yeast protein powder suspension at a mixing temperature of 20-25°C for 1-3 hours to hydrate it.

7. The preparation method according to claim 1, wherein, In step (1), the concentration of the yeast protein powder suspension is 10-30 mg / mL.

8. The preparation method according to claim 1, wherein, In step (4), the drying is freeze drying.

9. The preparation method according to claim 8, wherein, The freeze-drying time is 40-60 hours and / or the freeze-drying temperature is -45℃ to -55℃.

10. The preparation method according to any one of claims 1-9, wherein, The dual-modified yeast protein heat-induced gel has a light transmittance of 4.00-33.00, and / or a water retention of 75.00-99.90, and / or a hardness of 23.00-44.00, and / or an elasticity of 0.45-0.73, and / or a chewiness of 7.10-36.00, and / or a cohesiveness of 0.65-1.

16.

11. The preparation method according to claim 1, wherein, In the step of mixing the solid, dual-modified yeast protein purification with water, the mixing rate is 300-400 r / min and / or the mixing time is 1-4 h.

12. The preparation method according to claim 1, wherein, Before heating the mixed solution, the mixture is further subjected to a period of standing.

13. The preparation method according to claim 1, characterized in that, The cooling is ice-water bath cooling, wherein the ice-water bath temperature is 0-4℃ and / or the ice-water bath time is 10-15min.

14. A dual-modified yeast protein heat-induced gel, characterized in that, It is prepared by the preparation method according to any one of claims 1-13.

15. The application of the dual-modified yeast protein thermo-induced gel according to claim 14 in food, wherein, The food products include one or more of the following: simulated meat products, cheese substitutes, puddings, and edible films.

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