Gel of lycopene and konjac glucomannan for improving protein digestion and preparation method thereof

Abstract

The application discloses a preparation method of a lycopene and konjac glucomannan gel for improving protein digestion, and belongs to the technical field of food processing. In view of the technical problems that the dense network of polysaccharide inhibits protein digestion and high-concentration lycopene is prone to self-agglomeration, leading to unstable antioxidant effect in the prior art, the problems are solved through the following scheme: myofibrillar proteins and konjac glucomannan are mixed in a buffer solution to perform first hydration, and a protein-polysaccharide re-dissolution is obtained; then, a heat-labile protease is added to perform second hydration, and a protein-polysaccharide-enzyme re-dissolution is obtained; lycopene is mixed with edible oil to obtain a lycopene-oil phase; the oil phase is mixed with the enzyme re-dissolution to be homogenized to prepare an oil-in-water emulsion; finally, the temperature is increased from 25 DEG C to 80 DEG C at a rate of 1-3 DEG C / min and is kept for 20-40 min, and then the temperature is cooled to 2-6 DEG C and is kept for 12-24 h to perform heat-induced gelation. The application is mainly used for preparing a gel with high gel strength, good digestion performance and antioxidant stability.

Description

Technical Field

[0001] This invention relates to the field of food processing technology. More specifically, this invention relates to a gel made from lycopene and konjac glucomannan that improves protein digestion, and its preparation method. Background Technology

[0002] Myofibrillar proteins (MPs) are the main structural proteins in meat products, and their emulsifying and gelling properties are the core factors that determine the quality of meat products.

[0003] During processing, protein polysaccharides (MPs) are highly susceptible to oxidation and denaturation due to external environmental factors (such as pH, temperature, and ionic strength), leading to a decline in their functional properties. To improve this situation, existing technologies often employ the addition of polysaccharides (such as konjac glucomannan, KGM) to construct a dense gel network, thereby enhancing gel strength and water retention; or by adding natural antioxidants such as lycopene (LYC) to inhibit protein oxidation.

[0004] However, the above solutions have mutually restrictive technical flaws: 1. It is well known in the art that the dense network formed by water-soluble dietary fibers such as KGM can significantly restrict the diffusion of digestive enzymes and reduce the digestibility of proteins. This technical bias has severely limited its application in nutrition-oriented meat products. 2. The effect of adding LYC exhibits a significant concentration-dependent contradiction: low concentrations have limited effect, while high concentrations are prone to molecular self-aggregation, and in loosely structured systems, it even shows pro-oxidative characteristics, which exacerbates oxidative damage to proteins.

[0005] Currently, no technology can simultaneously resolve the inherent contradiction between the strength, oxidative stability, and nutrient digestibility of MPs gels. Furthermore, existing research has revealed the feasibility of modulating intermolecular forces (such as hydrophobic interactions and disulfide bonds) within the gel by introducing exogenous chemical reagents (e.g., octenyl succinic anhydride, glutathione). However, these methods rely on chemical additions, which not only contradicts the trend towards clean labeling but also makes it difficult to achieve predictable functional regulation based on natural components. For example, while Chen et al. (2023) innovatively used OSA and GSH to regulate hydrophobic interactions and disulfide bonds respectively, their regulatory signals are essentially "one-off" reagent responses, rather than dynamic, reversible molecular mechanisms driven by changes in component concentration.

[0006] Therefore, there is an urgent need for existing technologies that can improve the mechanical properties and antioxidant capacity of gels through the synergistic effect between natural components, while overcoming the technical bias of "polysaccharides inhibiting digestion". Summary of the Invention

[0007] One object of the present invention is to provide a method for preparing a gel that improves protein digestion using lycopene and konjac glucomannan, comprising the following steps: S1. Myofibrillar protein and konjac glucomannan are mixed in a buffer solution and subjected to a first hydration at 2-6°C to obtain a protein-polysaccharide complex solution, wherein the amount of konjac glucomannan added is 0.1%-1.2% of the total mass of the protein-polysaccharide complex solution; S2. Add a heat-instantaneous protease to the protein-polysaccharide complex solution obtained in step S1, and perform a second hydration at 2~6℃ to obtain a protein-polysaccharide-enzyme complex solution, wherein the heat-instantaneous protease is papain or bromelain, and the amount added is 0.1~0.5 U / mg of the myofibrillar protein. S3. Mix lycopene with edible oil to obtain a lycopene-oil phase, wherein the amount of lycopene added is 0.3% to 1.2% of the mass of the edible oil; S4. Mix the lycopene-oil phase obtained in step S3 with the protein-polysaccharide-enzyme complex solution obtained in step S2 and homogenize them to prepare an oil-in-water emulsion. S5. The oil-in-water emulsion obtained in step S4 is subjected to thermally induced gelation to obtain the gel. The heat-induced gelation process includes: heating the emulsion from 25°C to 80°C at a rate of 1~3°C / min, holding it at this temperature for 20~40 minutes, then cooling it to 2~-6°C and letting it stand for 12~24 hours.

[0008] Preferably, the amount of konjac glucomannan added in step S1 is 0.8% to 1.2% of the total mass of the protein-polysaccharide complex solution, and the amount of lycopene added in step S3 is 0.8% to 1.2% of the mass of the edible oil.

[0009] Preferably, the first hydration time in step S1 is 4 to 8 hours, and the second hydration time in step S2 is 8 to 16 hours.

[0010] Preferably, the heat-instantaneous protease is papain, and the second hydration is carried out in a buffer system with a pH of 6.0 to 6.5.

[0011] Preferably, the process of heating the emulsion from 25°C to 80°C at a rate of 1~3°C / min includes: First heating stage: The emulsion is heated from 25°C to 55°C at a rate of 0.5~1.5°C / min; Second heating stage: The emulsion is heated from 55°C to 80°C at a rate of 1.5~3.0°C / min.

[0012] Preferably, in the second heating stage, when the emulsion temperature reaches 70~75°C, this temperature range is maintained for 5~10 minutes, and then the temperature is further increased to 80°C.

[0013] Preferably, the mixing of lycopene and edible oil in step S3 is performed by stirring, and the stirring time is 5-6 hours and the temperature is 25-40℃.

[0014] Preferably, the method further includes a post-processing step on the gel obtained in step S4, wherein the post-processing is selected from any of the following: Pre-frozen at -50℃, freeze-dried at -80℃ for 48 h, and then ground and sieved for use in dry mixing and formulation. Spray drying with an inlet air temperature of 160℃ and an outlet air temperature of 80℃ is used for functional beverages. Freeze at -20°C or below for use in injectable meat products.

[0015] A gel prepared by the method described herein is provided that improves protein digestion by combining lycopene and konjac glucomannan.

[0016] Preferably, the gel for improving protein digestion with lycopene and konjac glucomannan comprises a protein network formed by myofibrillar proteins and a konjac glucomannan molecular chain network running through the protein network. The average pore size of the protein network is 15-30 μm, and the encapsulation rate of lycopene in the gel is not less than 85%. After being stored at 4°C in the dark for 14 days, the lycopene retention rate is not less than 80%.

[0017] The present invention has at least the following beneficial effects: First, the present invention adds a heat-instantaneous protease to the protein-polysaccharide complex solution for secondary hydration, thereby performing limited enzymatic hydrolysis of myofibrillar proteins. This avoids the inhibition of digestive enzyme diffusion by the dense network of konjac glucomannan, and improves the degree of in vitro digestion and hydrolysis of proteins. Experiments show that Example 4, which uses enzymatic hydrolysis treatment, has an in vitro digestion and hydrolysis degree of 48.5%, while the comparative example 2, which does not undergo enzymatic hydrolysis treatment, has a degree of only 35.1%.

[0018] Secondly, this invention adds lycopene-oil phase to protein-polysaccharide-enzyme complex solution to form an oil-in-water emulsion. The dense three-dimensional network formed by konjac glucomannan physically encapsulates lycopene, avoiding the self-aggregation of high-concentration lycopene. Experiments show that in Example 4 with added konjac glucomannan, the lycopene encapsulation rate reached 88.1%, and the retention rate after 14 days of storage at 4°C in the dark was 83.7%. In contrast, in Comparative Example 4 without added konjac glucomannan, the encapsulation rate was only 65.3%, and the retention rate after 14 days was as low as 50.5%.

[0019] Third, this invention employs a segmented programmed temperature rise process for thermally induced gelation, using a segmented heating method with a first heating stage and a second heating stage, and setting a heat preservation platform in the temperature range of 70~75℃. This promotes the orderly cross-linking of protein disulfide bonds. Tests show that Example 4, which uses programmed temperature rise, has a gel strength of 24.1 N, while Comparative Example 3, which uses rapid heating (8℃ / min, without segmentation and heat preservation), has a gel strength of only 16.5 N. This demonstrates that this process is crucial for forming a high-strength network.

[0020] Fourth, through systematic research, this invention is the first to discover and reveal a concentration-dependent synergistic effect in the myofibrillar protein (MPs)-konjac glucomannan (KGM)-lycopene (LYC) ternary system. Based on this, the "critical synergistic concentration" theory is proposed, which includes two key critical concentration points: First, the LYC mode switching point, that is, when the amount of LYC added exceeds a certain threshold (e.g., 0.5%), its effect changes from molecular-level dispersion promoting protein delamination to self-aggregation leading to functional decline; Second, the KGM network construction threshold, that is, when the amount of KGM added reaches a certain concentration (e.g., 1.0%)... When the concentration of KGM exceeds the critical overlap concentration (%), the molecular chains can form a dense three-dimensional polysaccharide network, driving the dominant force of the gel network to change from hydrophobic interaction to the synergistic dominance of disulfide bonds and hydrogen bonds. Based on these two critical concentrations, this invention further constructs a "three-functional region allocation strategy," dividing the concentration space into three functional regions: high emulsification type, high gel strength / high antioxidant type, and digestion-improving type. This achieves precise design of gel function. For example, when the KGM addition is 0.3% and the LYC addition is 0.5%, the gel network is dominated by hydrophobic interaction, with an emulsification activity index (EAI) ≥ 0.80 m² / g, suitable for high emulsification meat products. When the KGM addition is 1.0% and the LYC addition is 1.0%, the gel is dominated by the synergistic dominance of disulfide bonds and hydrogen bonds, with a gel strength ≥ 20.0 N and a TBARS value ≤ 0.30 mg MDA / kg, suitable for high gel strength / high antioxidant meat products.

[0021] Fifth, this invention reveals for the first time the environmentally dependent switching mechanism of LYC's antioxidant / pro-oxidative effects. Experiments have confirmed that the dense gel network constructed by KGM is the core prerequisite for LYC to exert its antioxidant activity, while in loosely structured systems, especially at high concentrations of LYC, it exhibits pro-oxidative characteristics. This discovery provides clear guidance on how to effectively utilize LYC.

[0022] Sixth, based on the in-depth correlation analysis of the microstructure and function of the gel network, this invention has established a number of quantitative control windows, including: an ionic bond-hydrogen bond “auxiliary dissociation window” (accounting for 15%~20% of the total intermolecular forces), an “optimal enzyme diffusion pore size window” of 15~30 μm, and a “conformation-optimal window” of 15%~25% of the endogenous tryptophan fluorescence intensity change rate. These windows constitute the cornerstone of this invention to achieve predictable and controllable functions.

[0023] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0024] Figure 1 This is a comparison of the emulsifying activity index (EAI) and surface hydrophobicity of emulsions from different treatment groups, where A represents the emulsifying activity index (EAI, m) of the emulsions from different treatment groups. 2 / g) bar chart, B is a bar chart of the surface hydrophobicity (relative fluorescence intensity) of the emulsion in different treatment groups; Figure 2 Bar chart showing the particle size distribution (D[4,3]) of emulsions from different treatment groups; Figure 3 The graph shows a comparison of gel strength and water holding capacity (WHC) of thermally induced gels in different treatment groups. In the graph, A is a bar chart of gel strength (N) of gels in different treatment groups, and B is a bar chart of water holding capacity (WHC, %) of gels in different treatment groups. Figure 4 A pie chart showing the proportion of intermolecular forces in gels from different treatment groups; Figure 5 This is a comparison chart of lipid oxidation (TBARS) and protein oxidation (carbonyl and total thiol) of gels in different treatment groups. In the chart, A is a bar chart of the degree of lipid oxidation (TBARS value, mg / kg) of gels in different treatment groups, B is a bar chart of the degree of protein oxidation (carbonyl content, nmol / mg) of gels in different treatment groups, C is a bar chart of the total thiol content (nmol / mg) of gels in different treatment groups, and D is a bar chart of the degree of protein oxidation (change in total thiol content) of gels in different treatment groups. Figure 6 The graph shows the comparison of the degree of hydrolysis (gastrointestinal stage) of gels in different treatment groups during simulated digestion. In the graph, A is a bar chart of the degree of hydrolysis (DH, %) of gels in different treatment groups during simulated gastric digestion, and B is a bar chart of the degree of hydrolysis (DH, %) of gels in different treatment groups during simulated intestinal digestion. Figure 7 A comparison of lycopene encapsulation efficiency and bioavailability of gels from different treatment groups; Figure 8Scanning electron microscopy (SEM) images of the gels from different treatment groups; Figure 9 Low-field nuclear magnetic resonance (LF-NMR) T2 relaxation spectra of gels from different treatment groups; Figure 10 The endogenous tryptophan fluorescence spectra of gels from different treatment groups; Figure 11 The graphs show the effects of different heating rates on the disulfide bond content and gel strength of the gel. A is a bar chart showing the change in the proportion of intermolecular forces (disulfide bonds, hydrophobic interactions, hydrogen bonds, and ionic bonds) of the gel during thermal induction at different heating rates (2℃ / min, 4℃ / min, and 10℃ / min). B is a bar chart comparing the gel strength at different heating rates, including unheated raw meat samples (CK group). Figure 12 Time-degree of hydrolysis curves at different digestion time points. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0026] It should be noted that, unless otherwise specified, the experimental methods described in the following implementation plan are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified.

[0027] 1. The enzymes used in this invention are as follows: Papain (enzyme activity ≥3000 U / mg): purchased from Beijing Bio-Lab Technology Co., Ltd. Bromelain (enzyme activity ≥2500 U / mg): purchased from Shanghai Yuanye Biotechnology Co., Ltd. Pepsin (enzyme activity ≥2500 U / mg) and pancreatin (enzyme activity ≥8×USP): purchased from Sigma-Aldrich, USA. Konjac glucomannan (KGM, purity ≥95%): purchased from Hubei Yizhi Konjac Biotechnology Co., Ltd. Lycopene (LYC, purity ≥98%): purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0028] 2. The main solutions are prepared as follows: Phosphate buffer (PBS, pH 6.5): Weigh 3.58 g of Na2HPO4·12H2O, 1.56 g of NaH2PO4·2H2O, and 8.5 g of NaCl, dissolve them in 800 mL of deionized water, adjust the pH to 6.5 with 1 mol / L NaOH or HCl, bring the volume to 1000 mL, and store at 4℃ for later use. Simulated gastric juice (SGF, pH 2.0): Weigh 2.0 g of NaCl, dissolve it in 800 mL of deionized water, adjust the pH to 2.0 with 1 mol / L HCl, add pepsin (enzyme activity 3200 U / mg) to a final concentration of 3.2 mg / mL, and bring the volume to 1000 mL. Simulated intestinal fluid (SIF, pH 7.0): Weigh 6.8 g of KH2PO4 and 2.0 g of NaCl, dissolve them in 800 mL of deionized water, adjust the pH to 7.0 with 1 mol / L NaOH, add trypsin (enzyme activity 8×USP) to a final concentration of 10 mg / mL, and bring the volume to 1000 mL.

[0029] <Example 1> Take fresh animal muscle tissue (selected from beef, pork, chicken or fish), remove visible fat and connective tissue, and mince it. This invention uses beef tenderloin (Simmental bull, 24 months old) as an example for illustration.

[0030] The minced muscle was mixed with pre-cooled phosphate extraction buffer (containing 0.1 mol / L NaCl, 10 mmol / L Na3PO4·12H2O, 2 mmol / L MgCl2, 1 mmol / L EGTA, pH 7.0) at a ratio of 1:4 (w / v), homogenized at 15,000 rpm for 30 s, with a 30 s interval, and repeated 3 times. The homogenized mixture was centrifuged at 4°C and 2,000 g for 10 min, and the supernatant was discarded. This step was repeated 3 times. Then, 0.1 mol / L NaCl solution was added to the precipitate and homogenized again. The precipitate was filtered through double gauze, and the filtrate was centrifuged at 4°C and 2,000 g for 10 min. The supernatant was discarded. This step was repeated 3 times. The final precipitate was myofibrillar protein.

[0031] The entire extraction process was carried out at 4°C, and the protein concentration was determined using the biuret method, with bovine serum albumin as the standard protein.

[0032] <Example 2> A method for preparing a gel that improves protein digestion using lycopene and konjac glucomannan includes the following steps: S1. Dissolve the myofibrillar proteins (MPs) extracted by the method described in Example 1 in 20 mmol / L phosphate buffer (containing 0.6 mol / L NaCl, pH 7.0) to prepare a protein solution with a final concentration of 50 mg / mL. Add konjac glucomannan (KGM, molecular weight ≥200 kDa) at a concentration of 0.1% of the total mass of the protein-polysaccharide complex solution and hydrate at 4°C for 4 hours. S2. Add bromelain (0.1 U / mg MPs) to the protein-polysaccharide complex solution obtained in S1, and perform a second hydration for 8 hours at 4℃ and pH 6.0. S3. Dissolve lycopene (LYC, purity ≥90%) powder in rapeseed oil, adding 0.3% of the oil phase mass, and stir magnetically for 5 hours at 25℃. S4. Mix the LYC-oil phase (oil phase volume fraction 20%) obtained in S3 with the protein-polysaccharide-enzyme complex solution obtained in S2, and homogenize at 12,000 rpm for 2 min to prepare an oil-in-water emulsion. S5. Place the emulsion in a water bath and heat it from 25°C to 80°C at a rate of 1°C / min. Keep it at 80°C for 20 minutes, then rapidly cool it to 4°C and let it stand for 24 hours to obtain a gel.

[0033] <Example 3> A method for preparing a gel that improves protein digestion using lycopene and konjac glucomannan includes the following steps: S1. Dissolve the myofibrillar proteins (MPs) extracted by the method described in Example 1 in 20 mmol / L phosphate buffer (containing 0.6 mol / L NaCl, pH 7.0) to prepare a protein solution with a final concentration of 50 mg / mL. Add konjac glucomannan (KGM, molecular weight ≥200 kDa) at a concentration of 0.1% of the total mass of the protein-polysaccharide complex solution and hydrate at 4°C for 4 hours. S2. Add bromelain (0.1 U / mg MPs) to the protein-polysaccharide complex solution obtained in S1, and perform a second hydration for 8 hours at 4℃ and pH 6.0. S3. Dissolve lycopene (LYC, purity ≥90%) powder in rapeseed oil, adding 0.3% of the oil phase mass, and stir magnetically for 5 hours at 25℃. S4. Mix the LYC-oil phase (oil phase volume fraction 20%) obtained in S3 with the protein-polysaccharide-enzyme complex solution obtained in S2, and homogenize at 12,000 rpm for 2 min to prepare an oil-in-water emulsion. S5. Place the emulsion in a water bath and perform heat-induced gelation as follows: In the first heating stage, heat the emulsion from 25°C to 55°C at a rate of 0.5°C / min; in the second heating stage, heat the emulsion from 55°C to 80°C at a rate of 1.5°C / min; in the second heating stage, when the temperature reaches 70°C, maintain this temperature for 5 minutes, and then continue to heat to 80°C; hold at 80°C for 20 minutes, then rapidly cool to 4°C and let stand for 24 hours to obtain the gel.

[0034] <Example 4> A method for preparing a gel that improves protein digestion using lycopene and konjac glucomannan includes the following steps: S1. Dissolve the myofibrillar proteins (MPs) extracted by the method described in Example 1 in 20 mmol / L phosphate buffer (containing 0.6 mol / L NaCl, pH 7.0) to prepare a protein solution with a final concentration of 50 mg / mL. Add konjac glucomannan (KGM, molecular weight ≥200 kDa) at a concentration of 0.8% of the total mass of the protein-polysaccharide complex solution and hydrate for 6 hours at 4°C. S2. Add bromelain (0.3 U / mg MPs) to the protein-polysaccharide complex solution obtained in S1, and perform a second hydration for 12 hours at 4℃ and pH 6.2. S3. Dissolve lycopene (LYC, purity ≥90%) powder in rapeseed oil, adding 0.8% of the oil phase mass, and magnetically stir at 30℃ for 5.5 hours. S4. Mix the LYC-oil phase (oil phase volume fraction 20%) obtained in S3 with the protein-polysaccharide-enzyme complex solution obtained in S2, and homogenize at 12,000 rpm for 2 min to prepare an oil-in-water emulsion. S5. Place the emulsion in a water bath and perform heat-induced gelation as follows: In the first heating stage, heat the emulsion from 25°C to 55°C at a rate of 1.0°C / min; in the second heating stage, heat the emulsion from 55°C to 80°C at a rate of 2.0°C / min; in the second heating stage, when the temperature reaches 72°C, maintain this temperature for 7 minutes, and then continue to heat to 80°C; hold at 80°C for 30 minutes, then rapidly cool to 4°C and let stand for 24 hours to obtain the gel.

[0035] <Example 5> A method for preparing a gel that improves protein digestion using lycopene and konjac glucomannan includes the following steps: S1. Dissolve the myofibrillar proteins (MPs) extracted by the method described in Example 1 in 20 mmol / L phosphate buffer (containing 0.6 mol / L NaCl, pH 7.0) to prepare a protein solution with a final concentration of 50 mg / mL. Add konjac glucomannan (KGM, molecular weight ≥200 kDa) at a concentration of 1.2% of the total mass of the protein-polysaccharide complex solution and hydrate for 8 hours at 4°C. S2. Add bromelain (0.5 U / mg MPs) to the protein-polysaccharide complex solution obtained in S1, and perform a second hydration for 16 hours at 4°C and pH 6.5. S3. Dissolve lycopene (LYC, purity ≥90%) powder in rapeseed oil, adding 1.2% of the oil phase mass, and stir magnetically for 6 hours at 40℃. S4. Mix the LYC-oil phase (oil phase volume fraction 20%) obtained in S3 with the protein-polysaccharide-enzyme complex solution obtained in S2, and homogenize at 12,000 rpm for 2 min to prepare an oil-in-water emulsion. S5. Place the emulsion in a water bath and perform heat-induced gelation as follows: In the first heating stage, heat the emulsion from 25°C to 55°C at a rate of 1.5°C / min; in the second heating stage, heat the emulsion from 55°C to 80°C at a rate of 3.0°C / min; in the second heating stage, when the temperature reaches 75°C, maintain this temperature for 10 minutes, and then continue to heat to 80°C; hold at 80°C for 40 minutes, then rapidly cool to 2°C and let stand for 24 hours to obtain the gel.

[0036] <Example 6> The preparation method of the gel that improves protein digestion with lycopene and konjac glucomannan is basically the same as that in Example 4, except that bromelain is replaced with papain and a second hydration is performed at pH 6.0.

[0037] <Comparative Example 1> The preparation method of the gel that improves protein digestion with lycopene and konjac glucomannan is basically the same as that in Example 4, except that the second hydration and enzymatic hydrolysis steps are skipped in step S2; and pure rapeseed oil is used in step S3 without adding lycopene.

[0038] <Comparative Example 2> The preparation method of the gel that improves protein digestion with lycopene and konjac glucomannan is basically the same as that in Example 4, except that the enzymatic hydrolysis step is skipped in step S2 and only the second hydration is performed for 12 hours.

[0039] <Comparative Example 3> The method for preparing the gel that improves protein digestion using lycopene and konjac glucomannan is basically the same as in Example 4, except that in step S5, the temperature is directly increased from 25°C to 80°C at a rate of 8°C / min, without segmented heating or a heat-holding platform. <Comparative Example 4> The preparation method of the gel that improves protein digestion with lycopene and konjac glucomannan is basically the same as that in Example 4, except that konjac glucomannan is not added in step S1.

[0040] <Key Performance Testing> The gels prepared in Examples 2-6 and Comparative Examples 1-4 were subjected to key performance tests according to the following standards, and the results are shown in Table 1 below: Gel strength determination: A TA.XT Plus texture analyzer was used with a P / 0.5 probe. The speed before testing was 1 mm / s, the speed during testing was 1 mm / s, the speed after testing was 10 mm / s, and the trigger force was 5 g. The results are expressed in Newtons (N). Determination of degree of hydrolysis (DH) in in vitro simulated digestion: The degree of protein hydrolysis was determined using the pH-stat method during a simulated gastrointestinal digestion phase. Lycopene (LYC) encapsulation rate determination: calculated using organic solvent extraction-spectrophotometry; Lycopene retention rate determination after 14 days of storage at 4℃ in the dark: The content was determined after 14 days using the same method as above, and the retention rate was calculated.

[0041] Table 1 Key Performance Test Results Example 2 8.5 38.5 72.3 65.1 Example 3 10.2 40.1 75.8 68.2 Example 4 24.1 48.5 88.1 83.7 Example 5 32.5 42.1 92.8 89.5 Example 6 25.8 50.2 87.5 84.0 Comparative Example 1 25.8 25.3 - - Comparative Example 2 21.3 35.1 85.4 82.0 Comparative Example 3 16.5 40.2 80.1 78.5 Comparative Example 4 12.5 38.0 65.3 50.5 As shown in Table 1, the overall performance (gel strength, digestibility, and antioxidant stability) of Examples 4, 5, and 6 of this invention is far superior to the following schemes: Comparative Example 1, which did not contain lycopene and was not enzymatically hydrolyzed, had a gel strength comparable to that of Example 4. However, the formation mechanisms of the two gels were different. Comparative Example 1 relied solely on the hydrophobic aggregation of myofibrillar proteins to form a brittle gel, while Example 4 involved the orderly cross-linking of proteins after enzymatic hydrolysis on a KGM network, resulting in a composite gel with higher toughness. The similarity in macroscopic gel strength values ​​does not necessarily mean that their microstructure and fracture toughness are the same. However, the degree of in vitro digestion and hydrolysis of Comparative Example 1 was much lower than that of Example 4, and it did not possess any antioxidant stability. This further highlights the comprehensive progress of the present invention in overcoming the defects of "polysaccharide-inhibited digestion" and "antioxidant instability". Comparative Example 4, without the addition of konjac glucomannan (KGM), resulted in extremely low gel strength, and a significant decrease in LYC encapsulation rate and 14-day retention rate, demonstrating that the dense network constructed by KGM is the basic framework of this system. Meanwhile, the retention rates of DH and LYC in the example group were significantly better than those in the comparative group, which proves that the KGM-LYC synergistic network, enzymatic hydrolysis pretreatment and programmed temperature rise process are the core essential technical features of the present invention, bringing about a qualitative leap. By comparing Examples 2, 3, and 4 with Example 4, it can be clearly demonstrated that the original steps of the present invention have unexpected technical effects: Comparing Example 4 and Comparative Example 2, when the enzymatic hydrolysis process was omitted in the pretreatment step, the DH dropped sharply from 48.5% to 35.1%, a decrease of 13.4 percentage points. This proves that enzymatic hydrolysis is a key and indispensable technical means to open the gel network and improve the accessibility of digestive enzymes. It is worth noting that the LYC encapsulation rate of Comparative Example 2 is not much different from that of Example 4. This is because enzymatic hydrolysis mainly acts on the protein network, while the KGM network is the main physical barrier for encapsulating LYC. This data proves that by precisely regulating the permeability of the protein network through enzymatic hydrolysis to promote digestion, while maintaining the protective effect of the KGM network on the active substances, the two do not interfere with each other and achieve functional synergy. Compared with Comparative Example 4 and Comparative Example 3, when the programmed temperature rise process of the present invention was replaced by a rapid temperature rise of 8℃ / min and a non-segmented temperature holding process, the gel strength dropped sharply from 24.1 N to 16.5 N, and the LYC embedding rate and retention rate also decreased. This shows that the programmed temperature rise strategy of the present invention is crucial for forming a uniform and dense gel network and locking in active substances. Comparing Example 4 with Comparative Example 4, when KGM was completely omitted, the gel strength and LYC retention performance dropped sharply. This clearly demonstrates that KGM is an essential component for constructing a dense three-dimensional network, imparting high strength to the gel, and providing a core protective microenvironment for LYC. Compared to Example 2, the gel strength of Example 4 increased from 8.5 N to 24.1 N, the DH increased from 38.5% to 48.5%, and the encapsulation rate and retention rate also increased significantly. This indicates that increasing the concentration of KGM and LYC and introducing enzymatic hydrolysis and segmented heating processes can synergistically enhance the gel structure and function.

[0042] Compared to Example 3, Example 4 shows significantly better performance in all aspects, demonstrating that optimizing from a simple constant-rate heating strategy to a segmented programmed heating strategy, coupled with a precise holding platform, can effectively promote the orderly cross-linking of protein disulfide bonds and network improvement.

[0043] In summary, this invention, through a unique combination of KGM-LYC ternary concentration ratio regulation, enzymatic pretreatment, and segmented programmed temperature rise process, successfully overcomes the technical bias of polysaccharides reducing protein digestibility and solves the problem of high-concentration KGM network inhibiting the accessibility of digestive enzymes. The resulting gel-based composite material is superior to existing conventional technologies and comparative schemes in terms of gel strength, digestive performance, and antioxidant stability.

[0044] <Example 7> To further verify the concentration-dependent synergistic effect among myofibrillar proteins (MPs), konjac glucomannan (KGM), and lycopene (LYC) in the technical solution of this invention, to illustrate the multi-level regulatory effect of each component within the numerical range described in this invention, and the intrinsic relationship between gel network structure and function, this embodiment systematically tests the performance of nine concentration combination gels and performs microstructural imaging to reveal their intrinsic mechanism of action, providing experimental support for this invention.

[0045] (1) Proportional design of nine groups of experiments Based on the different amounts of KGM added (based on the total mass of the emulsion) and LYC added (based on the mass of the oil phase, i.e., the total mass of lycopene mixed with edible oil in step S3), nine treatment groups were set up as shown in Table 2 below. It is worth noting that the amounts of KGM and LYC added are both within the range of process parameters defined in this invention (KGM: 0.1%~1.2%; LYC: 0.3%~1.2%), which is a full coverage study from low concentration to high concentration.

[0046] Table 2. Specific dosages for the 9 treatment groups K0-L0 0 0 K0-L0.5 0 0.5 K0-L1 0 1.0 K0.3-L0 0.3 0 K0.3-L0.5 0.3 0.5 K0.3-L1 0.3 1.0 K1-L0 1.0 0 K1-L0.5 1.0 0.5 K1-L1 1.0 1.0 (2) Preparation method Except for the different proportions, the preparation methods for all nine groups of samples were carried out in accordance with the core steps described in Example 4 of this invention, specifically including: S1. Dissolve the myofibrillar proteins (MPs) extracted by the method described in Example 1 in 20 mmol / L phosphate buffer (containing 0.6 mol / L NaCl, pH 7.0) to prepare a protein solution with a final concentration of 50 mg / mL. Weigh out the corresponding amounts of konjac glucomannan (KGM, molecular weight ≥200 kDa) and add them to the protein solution, so that the KGM addition amounts are 0%, 0.3%, and 1.0% (w / w, as a percentage of the total mass of the protein-polysaccharide complex solution), respectively. Perform the first hydration at 4°C, and adjust the time according to the KGM concentration: 12-18 hours when the KGM concentration is ≥0.3%; 4 hours when the KGM concentration is 0% as a control. S2. Add bromelain (0.3 U / mgMPs) to the protein-polysaccharide complex solution obtained in step S1, and perform a second hydration for 12 hours at 4°C and pH 6.2. S3. Dissolve lycopene (LYC, purity ≥90%) powder in rapeseed oil to prepare oil phase solutions with LYC addition amounts of 0%, 0.5% and 1.0% (w / w, as a percentage of oil phase mass). Stir the mixture magnetically at 30°C for 5.5 hours to ensure full dispersion. S4. Mix the LYC-oil phase (oil phase volume fraction 20%) obtained in step S3 with the protein-polysaccharide-enzyme complex solution obtained in step S2, and homogenize at 12,000 rpm for 2 min to prepare an oil-in-water emulsion. S5. The emulsion was placed in a water bath and thermally induced gelation was performed using a segmented temperature program: In the first heating stage, the emulsion was heated from 25°C to 55°C at a rate of 1.0°C / min; in the second heating stage, the emulsion was heated from 55°C to 80°C at a rate of 2.0°C / min; in the second heating stage, when the temperature reached 72°C, it was maintained at this temperature for 7 minutes, and then the temperature was further increased to 80°C; it was then held at 80°C for 30 minutes. Afterwards, it was rapidly cooled to 4°C and allowed to stand for 24 hours to obtain 9 different gels.

[0047] (3) Performance test methods and accompanying drawings To systematically characterize the various properties of the above nine groups of gels, this embodiment employs the following test methods, the results of which correspond to... Figures 1-10 As shown.

[0048] like Figure 1 The figure shows a comparison of the emulsification activity index (EAI) and surface hydrophobicity of emulsions from different treatment groups.

[0049] EAI was determined using a turbidimetric method. The freshly prepared emulsion was diluted 100-fold with 0.1% SDS solution, and the absorbance was measured at 500 nm. Figure 1 The results showed that the K0.3-L0.5 group exhibited a higher EAI (≥0.80 m). 2 / g), indicating that under the synergistic effect of appropriate amounts of KGM and LYC, the interfacial protein membrane structure is stable and the emulsification performance is excellent; Surface hydrophobicity was determined using the ANS fluorescent probe method. Data showed that the K0.3-L0.5 group had the highest relative fluorescence intensity, indicating that the moderate embedding of LYC promoted the exposure of hydrophobic regions of MPs, providing a prerequisite for the construction of a network dominated by hydrophobic interactions.

[0050] like Figure 2 The figure shows a bar chart of particle size distribution (D[4,3]) of emulsions from different treatment groups.

[0051] The volume average particle size D of the emulsion was determined using a laser particle size analyzer [4,3]. Figure 2 The results showed that the K0-L1 group had the largest particle size (134.9 μm), indicating that high-concentration LYC self-aggregated without the protection of the KGM network, leading to oil droplet coalescence. The K1-L1 group had the smallest particle size (1.99 μm), confirming that the high KGM network, as a steric barrier, effectively inhibited oil droplet coalescence and endowed the emulsion with ultra-high physical stability.

[0052] like Figure 3 The figure shown is a comparison of gel strength and water-holding capacity (WHC) of thermally induced gels in different treatment groups.

[0053] Gel strength was determined using a texture analyzer, and water-holding capacity (WHC) was determined by centrifugation. Figure 3 The results showed that with the increase of KGM concentration, both gel strength and WHC were significantly improved. The K1-L1 group had the highest gel strength (28.6 N) and its WHC reached 82.8%, indicating that the KGM network and the protein network formed a highly interpenetrating and dense structure, which can effectively bind water.

[0054] like Figure 4 The image shows a pie chart illustrating the proportions of intermolecular forces in gels from different treatment groups.

[0055] This invention quantitatively analyzes the contributions of hydrophobic interactions, disulfide bonds, hydrogen bonds, and ionic bonds to the stability of gel networks using a graded dissolution method. The "auxiliary dissociation window" is defined as a structural state in the gel network where the sum of the proportions of ionic bonds and hydrogen bonds in the non-covalent bonds is 15%–20%. This state was established based on numerous repeated experiments on samples (K0.3–L0.5 group) exhibiting a "first inhibited, then accelerated" digestion pattern in Example 9, statistically demonstrating that the ratio of ionic bonds to hydrogen bonds precisely falls within this range. Figure 4 The results showed that the K0.3-L0.5 group was dominated by hydrophobic interactions (highest proportion), with ionic bonds and hydrogen bonds accounting for approximately 17.3% of the total, falling within the 15%-20% "auxiliary dissociation window". The K1-L1 group, however, verified the "critical concentration 2" proposed in this invention, where the dominant forces shifted to a synergistic dominance of disulfide bonds and hydrogen bonds, resulting in a denser and more stable gel network. Figure 4 This provides direct experimental evidence for the core theoretical innovations of this invention, namely, the "critical synergistic concentration" and the "three-functional zone allocation strategy".

[0056] like Figure 5 The figure shows a comparison of lipid oxidation (TBARS) and protein oxidation (carbonyl groups, total thiol groups) in gels from different treatment groups.

[0057] TBARS values ​​are used to characterize the degree of lipid oxidation, while carbonyl content and total thiol content are used to assess the degree of protein oxidation. Figure 5 The results clearly validated the environment-dependent switching mechanism of LYC's antioxidant / pro-oxidative effects, which was first revealed in this invention: in loosely structured systems without KGM (K0-L1 group), high concentrations of LYC exhibited pro-oxidative characteristics, with the highest TBARS values ​​and carbonyl content; while in dense systems constructed with KGM (such as the K1-L1 group), the antioxidant activity of LYC was fully utilized, and the TBARS values ​​and carbonyl content were significantly reduced. Figure 5 This confirms that KGM serves as the core prerequisite for LYC to exert its antioxidant activity by "stabilizing the microenvironment".

[0058] like Figure 6 The figure shown is a comparison of the degree of hydrolysis (gastrointestinal stage) of gels in different treatment groups during in vitro simulated digestion.

[0059] The degree of protein hydrolysis (DH) in an in vitro simulated gastrointestinal digestion process was determined using the pH-stat method. Figure 6 The results showed that KGM alone did inhibit digestion (with the lowest DH in the K1-L0 group), but after the introduction of LYC, the DH of both the K1-L1 and K0.3-L0.5 groups was significantly higher than that of the K1-L0 group, especially the K0.3-L0.5 group, which reached the highest level. This figure directly proves that the present invention has successfully overcome the technical bias of polysaccharide inhibiting digestion. It is worth noting that after the introduction of LYC, the DH of both the K1-L1 and K0.3-L0.5 groups was significantly higher than that of the K1-L0 group, especially the K0.3-L0.5 group, which reached the highest level. This is highly consistent with its structural characteristics of being in the "auxiliary dissociation window" and "optimal enzyme diffusion pore size window", thus achieving controllable improvement of gel digestion properties.

[0060] like Figure 7 The figure shown is a comparison of the lycopene encapsulation efficiency and bioavailability of gels from different treatment groups.

[0061] The encapsulation efficiency of LYC was determined by organic solvent extraction-spectrophotometry, and its bioaccessibility was calculated by simulating the digestion process. Figure 7 The results showed that the encapsulation rate of the K1-L1 group was as high as 85% or more, while the biological accessibility of the K1-L0.5 group was the highest. This indicates that the KGM network effectively encapsulated LYC, but excessive KGM network density would limit its release. Therefore, the ratio needs to be optimized to balance encapsulation and release.

[0062] like Figure 8 The image shows the scanning electron microscope (SEM) microstructure of the gels from different treatment groups.

[0063] The microstructure of the lyophilized gel sections was observed using scanning electron microscopy (SEM). Figure 8 The results showed that the K0.3-L0.5 group had the most uniform and dense network structure with smooth pore walls and an average pore size falling within the "optimal enzyme diffusion pore size window" of 15-30 μm. This provided physical space for the rapid penetration and diffusion of digestive enzymes, which is the structural basis for its excellent digestive performance. The K1-L1 group had smaller pore size and a denser structure, which matched its high gel strength and high antioxidant properties.

[0064] like Figure 9 As shown, the low-field nuclear magnetic resonance (LF-NMR) T2 relaxation spectra of gels from different treatment groups are presented.

[0065] The T2 relaxation time of the water distribution in the gel was determined using a low-field nuclear magnetic resonance analyzer. Gels with different functional ratios exhibited distinct water distribution patterns. The peak area ratio of bound water, immobile water, and free water was closely related to the network density of the gel. Figure 9 The spectral data can serve as a rapid, non-destructive fingerprint feature for identifying the functional type of the gel.

[0066] like Figure 10 The image shows the endogenous tryptophan fluorescence spectra of gels from different treatment groups.

[0067] The fluorescence intensity of endogenous tryptophan was measured to characterize the effect of LYC on the tertiary structure of MPs. Figure 10 The results showed that the fluorescence change rate of the K0.3-L0.5 group was about 19.8%, which is within the "optimal conformation window" of 15% to 25%. This result indicates that LYC induces moderate protein unfolding, which exposes functional sites without causing disordered aggregation, and is the key conformational state for achieving excellent overall performance.

[0068] <Example 8> Verification of the effect of temperature-programmed process on the regulation of gel network structure and disulfide bond crosslinking To verify the specific regulatory effect of the segmented programmed heating process and intermediate heat preservation platform described in this invention on the gel network structure, especially on the promotion of disulfide bond crosslinking and the improvement of gel strength, this embodiment is established. This embodiment is based on the formulation of the K0.3-L0.5 group in Example 7, and compares the different effects of different heating rates on gel performance.

[0069] (1) Control group design Group A: The preparation method is the same as that of Group K0.3-L0.5 in Example 7, strictly following the segmented heating process (including holding at 72℃ for 7 minutes); Group B: The same batch of emulsion was heated at a faster rate: directly from 25°C to 80°C at a rate of 8°C / min. There were no segmentation or holding platform during the heating process. The remaining holding (holding at 80°C for 30 minutes), cooling and settling steps were exactly the same as those in Group A.

[0070] (2) Test methods and results description like Figure 11 The figure shown is a comparison of the effects of different heating rates on the disulfide bond content and gel strength of the gel.

[0071] The content of disulfide bonds in the gel during different heating processes was determined using Ellman's reagent method, and the gel strength was measured simultaneously. The results were compared with unheated raw meat samples (CK group) to reflect the aggregation dynamics of proteins during the heat-induced process.

[0072] Figure 11 The results showed that in group A, the contribution ratio of disulfide bonds steadily increased with increasing temperature during the thermal induction process, reaching a peak during the heat preservation stage. Simultaneously, the gel strength remained high (23.5 N), indicating a highly ordered structure. In group B (heating rate of 8℃ / min), the final contribution ratio of disulfide bonds was significantly lower than that in group A, while the contribution ratio of hydrophobic interactions was abnormally high. This reflected that under rapid heating, protein molecules underwent violent and disordered hydrophobic aggregation, failing to form sufficient covalent disulfide crosslinks. The direct consequence of this disordered aggregation was a sharp drop in the gel strength of group B to 18.1 N (a decrease of 23%), and the gel network was uneven, with localized pore collapse. Figure 11 The right-hand bar chart visually demonstrates the significant difference in gel strength between group A and group B.

[0073] This embodiment demonstrates that the heating rate itself is a key molecular switch affecting network configuration. The slow, segmented heating and intermediate holding plateau defined in this invention are core and necessary process features for achieving ordered thermal unfolding of protein molecules, promoting effective cross-linking of covalent disulfide bonds, and thus constructing an ordered and robust gel network. Skipping this step would prevent the comprehensive performance (high strength, high embedding rate, and controllable digestibility) described in this invention from being achieved.

[0074] <Example 9> Determination and analysis of in vitro simulated digestive kinetic curves To overcome the long-standing technical bias in this field that "polysaccharides (KGM) reduce protein digestibility," this invention not only demonstrates improved degree of hydrolysis (DH) at the digestion endpoint under specific ratios, but also systematically studies the complete kinetic process of protein DH changing with digestion time under different ratios. This embodiment reveals the unique "inhibition followed by acceleration" digestion kinetics induced by the synergistic system of LYC and KGM, providing direct and unexpected experimental evidence for the inventiveness of this invention.

[0075] (1) Experimental design and sample preparation In this embodiment, four representative groups of samples were selected for in vitro dynamic digestion experiments. The sample preparation method was the same as in Example 7 to ensure the consistency of the formulation and process: Control group (K0-L0): Blank control without KGM or LYC addition; Digestion inhibition group (K1-L0): only high concentration of KGM (1.0%) was added; The standard synergistic group (K0.3-L0.5): a combination of low KGM (0.3%) and medium LYC (0.5%); High-concentration synergistic group (K1-L1): combination of high KGM (1.0%) and high LYC (1.0%).

[0076] (2) In vitro simulated digestive kinetics experiment (based on the INFOOGS model) Simulated gastric digestion stages Preparation of simulated gastric fluid (SSF): Weigh 10 g of each of the four different ratios of gel samples mentioned above, and add an equal volume (10 mL) of simulated gastric fluid (containing 4.8 g / L NaCl, 0.6 g / L KCl, 0.11 g / L CaCl2, and porcine pepsin (derived from porcine gastric mucosa) to a final enzyme activity of 2000 U / mL). pH adjustment: Use 1 M HCl solution to precisely adjust the pH of the mixture to 3.0; Digestion and Sampling: The pH-adjusted mixture was placed in a 37°C constant-temperature shaking water bath at 120 rpm to simulate gastric digestion. At 0, 10, 20, 30, 40, 50, and 60 minutes after the start of digestion, 1 mL of sample was taken, and 1 M NaOH solution was immediately added to terminate enzyme activity. The sample was then stored on ice for subsequent DH value determination. The total duration of the gastric digestion phase was 60 minutes.

[0077] Simulated intestinal digestion stage Preparation of simulated intestinal fluid (SIF): Immediately after gastric digestion, add an equal volume (10 mL) of simulated intestinal fluid (containing pancreatic enzymes (from the pig pancreas) to a final pancreatic enzyme activity of 100 U / mL, and pig bile salts to a final concentration of 10 mM) to the digestive system. pH adjustment: Use 1 M NaOH solution to precisely adjust the pH of the mixture to 7.0; Digestion and Sampling: The pH-adjusted mixture was placed in a 37°C constant-temperature shaking water bath to continue simulated intestinal digestion. At 0, 30, 60, 90, and 120 minutes after the start of intestinal digestion, 1 mL of sample was taken, and a serine protease inhibitor (e.g., 1 mM 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride, AEBSF) solution was immediately added to terminate enzyme activity, and the sample was stored on ice.

[0078] Degree of hydrolysis (DH) determination The free amino content of samples taken at all time points was determined using the classic pH-stat method, combined with the trinitrobenzenesulfonic acid (TNBS) method or the o-phthalaldehyde (OPA) method. The degree of protein hydrolysis (DH%) of each sample at different time points was calculated according to the following formula: ,in,( NH 2 ) t yes t The amount of free amino groups in the sample at a given time, NH2 ) 0 It is the amount of free amino groups in the sample at the start of digestion (time 0). NH 2 ) total It is the total amount of free amino groups after the sample is completely acid-hydrolyzed (6M HCl, 110℃, 24 hours).

[0079] (3) Experimental results and kinetic curve analysis The DH values ​​at different digestion time points were plotted as time-degree of hydrolysis curves, and the results are as follows: Figure 12 As shown, the findings are as follows: In the early stages of gastric digestion (approximately the first 30 minutes), the DH curves of the four samples began to differentiate. Compared to the control group (K0-L0), the digestion inhibition group (K1-L0) showed the slowest rise in its DH curve and the lowest overall level. This clearly confirms common knowledge in the art: the dense gel network formed by high concentrations of KGM (1.0%) does indeed severely restrict the diffusion of pepsin and its contact with the substrate, thereby significantly inhibiting the initial hydrolysis of proteins. This is consistent with Comparative Example 1 and the expectations of this invention, demonstrating that the inhibitory effect of KGM is validated in the initial stage (0-60 min of gastric digestion).

[0080] After entering the intestinal digestion stage, Digestion inhibition group (K1-L0): Its DH curve remained flat during the intestinal digestion stage, and it failed to get rid of the inhibitory effect of KGM. The final DH value was significantly lower than that of the control group. The high-concentration synergistic group (K1-L1) showed a clear upward inflection point in its DH curve at the end of gastric digestion and the early stage of intestinal digestion (about 60-90 minutes). In the middle and late stages of intestinal digestion, its DH growth rate accelerated significantly. The final DH value was not only much higher than that of the K1-L0 group in its ratio, but also exceeded that of the control group (K0-L0). In the middle and late stages (30-120 minutes of intestinal digestion), it showed a unique pattern of "reversing inhibition and successfully surpassing".

[0081] The conventional synergistic group (K0.3-L0.5) exhibited a more pronounced "accelerated overtaking" phenomenon in digestion. In the first 30 minutes (60-90 minutes) of intestinal digestion, the slope of its DH curve began to increase significantly, and the DH value reached the highest value among the four groups at about 120 minutes, showing a typical kinetic characteristic of "accelerated rise and eventual overtaking".

[0082] This embodiment, through detailed digestion kinetic curves, reveals and proves for the first time that: The MPs-KGM-LYC synergistic system described in this invention does not simply "counteract" or "ignore" the inhibitory effect of KGM on digestion. On the contrary, the introduction of LYC changes the physicochemical properties of the gel network, allowing the gel to maintain the excellent anti-swelling properties conferred by KGM in the early stages of digestion (manifested as slowed initial exudation and inhibition of rapid early diffusion of proteases). In the later stages of digestion, through the "auxiliary dissociation window function" or "large-scale exposure of enzyme cleavage sites" induced by the network structure of LYC, a unique and unpredictable new protein digestion mode of "inhibition first, acceleration later, and finally overtaking" is initiated.

[0083] This unique digestive kinetics model breaks with the conventional thinking of those skilled in the art, which is based on the "empirical knowledge that polysaccharides inhibit digestion." The synergistic combination of the present invention (especially the K0.3-L0.5 and K1-L1 ratio) not only overcomes the problem of KGM reducing digestibility, but also creates a novel time-release characteristic that is more conducive to protein nutrient absorption. This is a technical effect that cannot be inspired or taught by existing technologies, and provides highly convincing experimental support for the inventiveness of the present invention.

[0084] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing a gel that improves protein digestion using lycopene and konjac glucomannan, characterized in that, Includes the following steps: S1. Myofibrillar protein and konjac glucomannan are mixed in a buffer solution and subjected to a first hydration at 2-6°C to obtain a protein-polysaccharide complex solution, wherein the amount of konjac glucomannan added is 0.1%-1.2% of the total mass of the protein-polysaccharide complex solution; S2. Add a heat-instantaneous protease to the protein-polysaccharide complex solution obtained in step S1, and perform a second hydration at 2~6℃ to obtain a protein-polysaccharide-enzyme complex solution, wherein the heat-instantaneous protease is papain or bromelain, and the amount added is 0.1~0.5 U / mg of the myofibrillar protein. S3. Mix lycopene with edible oil to obtain a lycopene-oil phase, wherein the amount of lycopene added is 0.3% to 1.2% of the mass of the edible oil; S4. Mix the lycopene-oil phase obtained in step S3 with the protein-polysaccharide-enzyme complex solution obtained in step S2 and homogenize them to prepare an oil-in-water emulsion. S5. The oil-in-water emulsion obtained in step S4 is subjected to thermally induced gelation to obtain the gel. The heat-induced gelation process includes: heating the emulsion from 25°C to 80°C at a rate of 1~3°C / min, holding it at this temperature for 20~40 minutes, then cooling it to 2~-6°C and letting it stand for 12~24 hours.

2. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 1, characterized in that, The amount of konjac glucomannan added in step S1 is 0.8% to 1.2% of the total mass of the protein-polysaccharide complex solution, and the amount of lycopene added in step S3 is 0.8% to 1.2% of the mass of the edible oil.

3. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 1, characterized in that, In step S1, the first hydration time is 4 to 8 hours, and in step S2, the second hydration time is 8 to 16 hours.

4. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 1, characterized in that, The heat-instable protease is papain, and the second hydration is carried out in a buffer system with a pH of 6.0 to 6.

5.

5. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 1, characterized in that, The process of heating the emulsion from 25°C to 80°C at a rate of 1~3°C / min includes: First heating stage: The emulsion is heated from 25°C to 55°C at a rate of 0.5~1.5°C / min; Second heating stage: The emulsion is heated from 55°C to 80°C at a rate of 1.5~3.0°C / min.

6. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 5, characterized in that, In the second heating stage, when the emulsion temperature reaches 70~75℃, maintain this temperature range for 5~10 minutes, and then continue to heat up to 80℃.

7. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 1, characterized in that, The operation of mixing lycopene and edible oil in step S3 is to stir and mix for 5 to 6 hours at a temperature of 25 to 40°C.

8. The method for preparing a gel using lycopene and konjac glucomannan to improve protein digestion as described in claim 1, characterized in that, The process also includes a post-processing step on the gel obtained in step S4, wherein the post-processing is selected from any of the following: Pre-frozen at -50℃, freeze-dried at -80℃ for 48 h, and then ground and sieved for use in dry mixing and formulation. Spray drying with an inlet air temperature of 160℃ and an outlet air temperature of 80℃ is used for functional beverages. Freeze at -20°C or below for use in injectable meat products.

9. A gel containing lycopene and konjac glucomannan prepared by any one of claims 1 to 8, which improves protein digestion.

10. The gel for improving protein digestion using lycopene and konjac glucomannan as described in claim 9, characterized in that, The gel comprises a protein network formed by myofibrillar proteins and a konjac glucomannan molecular chain network running through the protein network. The average pore size of the protein network is 15-30 μm, and the encapsulation rate of lycopene in the gel is not less than 85%. After being stored at 4°C in the dark for 14 days, the lycopene retention rate is not less than 80%.

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