Method for microwave-assisted metal ion optimization of emulsification performance of wheat germ protein

Abstract

The application discloses a method for optimizing emulsification performance of wheat germ protein by microwave-assisted metal ions, and comprises the following steps: (1) mixing wheat germ powder and an incubation solution containing metal ions to obtain a mixed solution; (2) microwave treating the mixed solution and water-bath incubating to obtain optimized wheat germ protein homogenate; the microwave treatment power is 350-450 W, and the microwave treatment time is 9-11 s. The method greatly reduces the production difficulty of the novel wheat germ protein product, improves the utilization rate of the wheat germ protein, and is green, safe, economic, convenient and cost-saving.

Description

Technical Field

[0001] This invention relates to a method for optimizing the emulsification performance of wheat germ protein with microwave-assisted metal ions, belonging to the field of comprehensive utilization of agricultural and sideline products. Background Technology

[0002] Wheat germ, the core and lifeblood of wheat, is mainly composed of the embryo and scutellum, and is a highly nutritious byproduct of wheat processing. Wheat germ contains approximately 30% protein. Wheat germ proteins can be classified into four types: prolamins, glutenins, albumins, and globulins, with albumin and globulins being the most abundant. Wheat germ proteins contain all eight essential amino acids, making them a high-quality protein source with broad application prospects in food research and development. However, as a wheat processing byproduct, wheat germ is often sold directly to feed mills at low prices, resulting in limited research on the development and utilization of functional substances from wheat germ, leading to a significant waste of wheat germ resources. Although research on the extraction and in-depth utilization of wheat germ proteins is beginning to take shape, the deep processing of wheat germ proteins is affected by some of their functional properties, and there is a lack of research on their functional characteristics. Therefore, expanding the application of wheat germ proteins in food processing and reducing the waste of wheat germ protein resources is of practical significance.

[0003] After being ground, wheat germ can be directly added to food, such as wheat germ bread, wheat germ steamed buns, wheat germ noodles, wheat germ biscuits, non-fermented beverages, and fermented beverages. The impact of protein on food quality persists throughout production, processing, and storage. This is attributed to the physicochemical properties of proteins, also known as functional properties, including water-holding capacity, oil-holding capacity, emulsifying properties, foaming properties, solubility, and antioxidant properties. These physicochemical properties are interconnected. Protein modification methods mainly include physical modification, chemical modification, and enzymatic modification. Chemical modification is widely used due to its simplicity, safety, reliability, and cost-effectiveness, but it has a significant impact on protein quality. Physical modification has become a popular method in recent years. It utilizes heat treatment, ultrasound, microwave treatment, high-pressure treatment, or mechanical energy to alter the molecular structure and aggregation mode of proteins, thereby modifying the protein molecules. This method is simple, environmentally friendly, and safe. With the continuous development of microwave technology, it has been widely used in protein modification in the food industry. However, challenges remain. Firstly, due to the differences in protein types, different microwave treatment times and powers will produce different effects. Secondly, improper control of the microwave's thermal effect can easily cause protein denaturation. However, further research into protein modification has revealed that the combined effect of different technologies is often greater than that of individual technologies. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for optimizing the emulsification performance of wheat germ protein with microwave-assisted metal ions. The method can effectively improve the utilization rate of wheat germ protein, and has low equipment requirements, is environmentally friendly, and greatly saves implementation costs.

[0005] Technical Solution: To solve the above-mentioned technical problems, this invention provides a method for optimizing the emulsification performance of wheat germ protein with microwave-assisted metal ions, comprising the following steps:

[0006] (1) Mix wheat germ powder with an incubation solution containing metal ions to obtain a mixture, wherein the metal ions include Zn. 2+ Mn 2+ or Ca 2+ The Zn 2+ The concentration of Mn is 0.9–1.2 mmol / L. 2+ The concentration of Ca is 1.4–1.6 mmol / L. 2+ The concentration was 1.3–1.5 mmol / L;

[0007] (2) The mixture is microwave-treated and incubated in a water bath to obtain an optimized wheat germ protein homogenate; the microwave treatment power is 350-450W and the microwave treatment time is 9-11s.

[0008] Preferably, when the metal ions include Zn 2+ Mn 2+ or Ca 2+ The Zn 2+ The concentration of Mn is 1.0 mmol / L. 2+ The concentration of Ca was 1.6 mmol / L. 2+ The concentration of the metal ion was 1.4 mmol / L; the microwave treatment power was 400 W and the microwave treatment time was 10 s, when the wheat germ protein emulsification performance of the microwave-metal ion group was the best.

[0009] In step (1), the mass-to-volume ratio of wheat germ powder and incubation solution is 1:8-10 g / mL.

[0010] The pH value of the incubation solution in step (1) is 2.9 to 3.1.

[0011] The incubation solution in step (1) contains 0.08 to 0.1 mol / L of citric acid-sodium citrate.

[0012] In step (2), the water bath incubation temperature is 48-50℃ and the time is 5-7h.

[0013] Reaction Principle: The application of microwave technology to protein modification is mainly based on the non-thermal effects of microwaves. On the one hand, the non-thermal effects on proteins increase the content of β-sheets and α-helices, while decreasing the content of β-turns and random coils, resulting in a looser protein molecular structure and a reduced molecular weight, directly affecting the functional properties of the protein. On the other hand, certain metal ions can activate endogenous proteases in wheat germ. After hydrolysis by these proteases, functional peptides are produced, which also have a certain impact on the final structural and functional properties of the protein. The combined effect of these two factors influences the protein's structure and, consequently, its functional properties.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0015] 1. Improved utilization of wheat germ protein: The solubility, water retention, oil retention, antioxidant properties, emulsifying properties, and emulsion stability of wheat germ protein after combined microwave and metal ion treatment were increased by 85.84%, 22.85%, 82.14%, 9.48%, 120.91%, and 15.64%, respectively, compared with untreated wheat germ protein. Moreover, the enhancement effect in solubility, water retention, and oil retention was better than the effect of the single treatment. This optimization greatly reduced the difficulty of manufacturing new wheat germ protein products and improved the utilization rate of wheat germ protein.

[0016] 2. The modification method is green, safe, economical and convenient: The microwave combined with metal ion method adopted in this invention has low equipment requirements, is green and environmentally friendly, and greatly saves implementation costs. Attached Figure Description

[0017] Figure 1 The wheat germ protein powder forms obtained under different processing methods in Example 1;

[0018] Figure 2 The effect of different processing methods on the solubility of wheat germ protein prepared in Example 1;

[0019] Figure 3 The effect of different processing methods on the water-holding and oil-holding properties of wheat germ protein prepared in Example 1;

[0020] Figure 4 To determine the molecular weight of wheat germ protein obtained in Example 1 under different processing methods (1: control group; 2: microwave group; 3: metal ion group; 4: microwave-metal ion group);

[0021] Figure 5 Scanning electron micrographs of wheat germ protein obtained in Example 1 under different processing methods (a: control group; b: microwave group; c: metal ion group; d: microwave-metal ion group);

[0022] Figure 6Infrared spectra of wheat germ protein amide I obtained in Example 1 under different processing methods;

[0023] Figure 7 The effect of different processing methods on the emulsifying properties and emulsifying stability of wheat germ protein prepared in Example 1;

[0024] Figure 8 This is a comparison of the solubility of wheat germ protein prepared in Examples 1-4;

[0025] Figure 9 This is a comparison of the water-holding capacity of wheat germ protein obtained in Examples 1-4;

[0026] Figure 10 This is a comparison of the oil-holding properties of wheat germ proteins prepared in Examples 1-4;

[0027] Figure 11 This is a comparison of the emulsifying properties of wheat germ proteins prepared in Examples 1-4. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0029] Example 1

[0030] Isolated wheat germ (provided by Danyang Lianhu Flour Co., Ltd.) was selected as raw material and pulverized through a 40-mesh sieve. Homogenizements were obtained through separate processing. Preparation of the incubation solution (0.1 mol / L pH 3.0 citric acid-sodium citrate buffer): 0.1 mol / L citric acid solution and 0.1 mol / L sodium citrate solution were mixed at a volume ratio of 93:7. Control group: Incubation solution was added at a ratio of 1:10 (g / mL) and incubated in a 49℃ water bath for 6 hours. Microwave group: Incubation solution was added at a ratio of 1:10 (g / mL), thoroughly mixed, microwaved at 400W for 10 seconds, and then incubated in a 49℃ water bath for 6 hours. Metal ion group: Incubation solution was added at a ratio of 1:10 (g / mL), with ZnSO4 concentration of 1.0 mmol / L, MnSO4 concentration of 1.6 mmol / L, and CaCl2 concentration of 1.4 mmol / L. After thorough mixing, incubate in a 49℃ water bath for 6 hours. Microwave metal ion group: Add incubation solution at a material-to-solution ratio of 1:10 (g / mL). The concentrations of ZnSO4, MnSO4, and CaCl2 in the incubation solution are 1.0 mmol / L, 1.6 mmol / L, and 1.4 mmol / L, respectively. After thorough mixing, microwave at 400W for 10 seconds, then incubate in a 49℃ water bath for 6 hours.

[0031] After wheat germ incubation, the resulting homogenate was centrifuged at 4000 rpm for 20 min at 4℃. The supernatant was discarded, and the precipitate was dissolved in distilled water at a material-to-liquid ratio of 1:16 (g / mL). The pH was adjusted to 10.0 using 2% NaOH solution. After extraction at 60℃ for 1 h, the homogenate was centrifuged at 4000 rpm for 20 min. The supernatant was collected, and the pH was adjusted to 4.0 using 2% HCl. After acid precipitation at 60℃ for 2 h, the homogenate was centrifuged at 4000 rpm for 20 min to obtain wheat germ protein precipitate. The precipitate was washed several times with water until neutral, and then dried in a vacuum freeze dryer for 36 h. The resulting freeze-dried protein was then pulverized for later use. Figure 1 As shown.

[0032] Example 2

[0033] Isolated wheat germ was selected as raw material and pulverized through a 40-mesh sieve. Homogenizements were obtained through separate processing. Control group: 20g / part wheat germ powder was weighed. An incubation solution containing 0.08mol / L citric acid-sodium citrate (0.1mol / L citric acid solution and 0.1mol / L sodium citrate solution) at pH 2.9 was added at a material-to-liquid ratio of 1:8 (g / mL), and incubated in a 48℃ water bath for 5 hours. Microwave group: 20g / part wheat germ powder was weighed and added to an incubation solution containing 0.08mol / L citric acid-sodium citrate at pH 2.9 at a material-to-liquid ratio of 1:8 (g / mL). After thorough mixing, the mixture was microwaved at 350W for 9 seconds and then incubated in a 48℃ water bath for 5 hours. Metal ion group: Weigh 20g / part of wheat germ powder and add it to an incubation solution with pH 2.9 at a material-to-liquid ratio of 1:8 (g / mL). The incubation solution contains 0.9 mmol / L ZnSO4, 1.4 mmol / L MnSO4, and 1.3 mmol / L CaCl2. After thorough mixing, incubate in a 48℃ water bath for 5 hours. Microwave-metal ion group: Weigh 20g / part of wheat germ powder and add it to an incubation solution with pH 2.9 at a material-to-liquid ratio of 1:8 (g / mL). The incubation solution contains 0.9 mmol / L ZnSO4, 1.4 mmol / L MnSO4, and 1.3 mmol / L CaCl2. After thorough mixing, microwave at 350W for 9 seconds, then incubate in a 48℃ water bath for 5 hours.

[0034] After the wheat germ incubation was completed, the resulting homogenate was centrifuged at 4000 r / min for 20 min at 4℃, the supernatant was discarded, and the precipitate was dissolved in distilled water at a material-to-liquid ratio of 1:16 (g / mL). The pH was adjusted to 10.0 with 2% NaOH solution, and extracted at 60℃ for 1 h. After centrifugation at 4000 r / min for 20 min, the supernatant was collected, and the pH was adjusted to 4.0 with 2% HCl. After acid precipitation at 60℃ for 2 h, the precipitate was centrifuged at 4000 r / min for 20 min to obtain wheat germ protein precipitate. The precipitate was washed with water several times until it was neutral, and then dried in a vacuum freeze dryer for 36 h. The freeze-dried protein was then pulverized for later use.

[0035] Example 3

[0036] Isolated wheat germ was selected as raw material and pulverized through a 50-mesh sieve. Homogenized slurries were obtained through separate processing. Control group: 20 g / part wheat germ powder was weighed and added to an incubation solution containing 0.09 mol / L citric acid-sodium citrate at pH 3.0 at a material-to-liquid ratio of 1:9 (g / mL). The mixture was incubated in a 49℃ water bath for 6 hours. Microwave group: 20 g / part wheat germ powder was weighed and added to an incubation solution at pH 3.0 at a material-to-liquid ratio of 1:9 (g / mL). After thorough mixing, the mixture was microwaved at 400W for 10 seconds and then incubated in a 49℃ water bath for 6 hours. Metal ion group: 20 g / part wheat germ powder was weighed and added to an incubation solution at pH 3.0 at a material-to-liquid ratio of 1:9 (g / mL). The incubation solution contained 1 mmol / L ZnSO4, 1.5 mmol / L MnSO4, and 1.4 mmol / L CaCl2. After thorough mixing, incubate in a 49℃ water bath for 6 hours. Microwave-metal ion group: Weigh 20g / part of wheat germ powder and add it to an incubation solution with pH 3.0 at a material-to-liquid ratio of 1:9 (g / mL). The incubation solution contains 1 mmol / L ZnSO4, 1.5 mmol / L MnSO4, and 1.4 mmol / L CaCl2. After thorough mixing, microwave at 400W for 10 seconds, then incubate in a 49℃ water bath for 6 hours.

[0037] After the wheat germ incubation was completed, the resulting homogenate was centrifuged at 4000 r / min for 20 min at 4℃, the supernatant was discarded, and the precipitate was dissolved in distilled water at a material-to-liquid ratio of 1:16 (g / mL). The pH was adjusted to 10.0 using 2% NaOH solution, and extracted at 60℃ for 1 h. After centrifugation at 4000 r / min for 20 min, the supernatant was collected, and the pH was adjusted to 4.0 using 2% HCl. After acid precipitation at 60℃ for 2 h, the wheat germ protein precipitate was obtained by centrifugation at 4000 r / min for 20 min. The precipitate was washed with water several times until it was neutral, and then dried in a vacuum freeze dryer for 36 h. The freeze-dried product was then pulverized for later use.

[0038] Example 4

[0039] Isolated wheat germ was selected as raw material and pulverized through a 60-mesh sieve. Homogenized slurries were obtained through separate processing. Control group: 20 g / part of wheat germ powder was weighed and added to an incubation solution containing 0.1 mol / L citric acid-sodium citrate at pH 3.1 at a material-to-liquid ratio of 1:10 (g / mL). The mixture was then incubated in a 50℃ water bath for 7 h. Microwave group: 20 g / part of wheat germ powder was weighed and added to an incubation solution at pH 3.1 at a material-to-liquid ratio of 1:10 (g / mL). After thorough mixing, the mixture was microwaved at 450W for 11 s and then incubated in a 50℃ water bath for 7 h. Metal ion group: 20 g / part of wheat germ powder was weighed and added to an incubation solution at pH 3.1 at a material-to-liquid ratio of 1:10 (g / mL). The incubation solution contained ZnSO4 at a concentration of 1.2 mmol / L, MnSO4 at a concentration of 1.6 mmol / L, and CaCl2 at a concentration of 1.5 mmol / L. After thorough mixing, incubate in a 50℃ water bath for 7 hours. Microwave-metal ion group: Weigh 20g / part of wheat germ powder and add it to an incubation solution with pH 3.1 at a material-to-liquid ratio of 1:10 (g / mL). The incubation solution contains 1.2 mmol / L ZnSO4, 1.6 mmol / L MnSO4, and 1.5 mmol / L CaCl2. After thorough mixing, microwave at 450W for 11 seconds, then incubate in a 50℃ water bath for 7 hours.

[0040] After the wheat germ incubation was completed, the resulting homogenate was centrifuged at 4000 r / min for 20 min at 4℃, the supernatant was discarded, and the precipitate was dissolved in distilled water at a material-to-liquid ratio of 1:16 (g / mL). The pH was adjusted to 10.0 using 2% NaOH solution, and extracted at 60℃ for 1 h. After centrifugation at 4000 r / min for 20 min, the supernatant was collected, and the pH was adjusted to 4.0 using 2% HCl. After acid precipitation at 60℃ for 2 h, the wheat germ protein precipitate was obtained by centrifugation at 4000 r / min for 20 min. The precipitate was washed with water several times until it was neutral, and then dried in a vacuum freeze dryer for 36 h. The freeze-dried product was then pulverized for later use.

[0041] Example 5

[0042] The lyophilized powder obtained in Example 1 was selected, and the solubility of its wheat germ protein was determined. The content of soluble wheat germ protein was determined using the Coomassie Brilliant Blue method, and the solubility of each group of wheat germ protein was calculated and analyzed. The solubility of wheat germ protein is closely related to other functional properties and is an extremely important characteristic. Whether the molecule is hydrophilic, what kind of charge the molecule carries, and the size of the molecular weight determine the solubility of the protein. For example... Figure 2As shown, the solubility of wheat germ protein extracted from the four treatment groups (control group, microwave group, metal ion group, and microwave-metal ion group) was 22.46±1.55%, 32.99±0.28%, 35.05±0.16%, and 41.91±0.16%, respectively. Compared with the control group, the protein solubility measured in the microwave group, metal ion group, and microwave-metal ion group was improved, with the microwave-metal ion group showing the best solubility.

[0043] Example 6

[0044] The lyophilized powder obtained in Example 1 was selected, and its water-holding and oil-holding properties of wheat germ protein were measured. The changes and significant differences in water-holding and oil-holding properties of wheat germ protein before and after modification are shown below. Figure 3 As shown, the water-holding capacity of wheat germ protein before modification (control group) was 2.85±0.06 g / g, and the oil-holding capacity was 2.12±0.02 g / g. After microwave, metal ion, and microwave-metal ion modification, the water-holding capacity and oil-holding capacity of the microwave-metal ion group increased by 22.85% and 82.14% respectively compared with the previous values. Moreover, the water-holding capacity and oil-holding capacity of wheat germ protein under the combined action of microwave and metal ion were much higher than those under the individual modification. Under the synergistic effect of microwave and metal ion, the disulfide bonds of the protein in wheat germ are broken, the protein macromolecules are degraded, the molecular weight is reduced, and the internal adsorption groups are exposed, which is conducive to the entry of water and oil. At the same time, the small molecule protein forms a complex with the metal ion, forming a loose and porous structure that easily accommodates solvents. Therefore, the wheat germ protein modified by microwave-metal ion has better water-holding capacity and oil-holding capacity.

[0045] Example 7

[0046] The lyophilized powder obtained in Example 1 was selected, and its emulsifying properties and emulsifying stability were determined. The wheat germ protein, both before and after modification, showed superior emulsifying properties. After microwave-assisted metal ion modification, the emulsifying properties of the wheat germ protein improved compared to the previous 16.31 m... 2 / g increased by 120.91% (Table 1). For example... Figure 7 As shown, the improved emulsificability is due to the decrease in molecular weight and increase in solubility of wheat germ protein under the action of microwaves and metal ions, resulting in greater molecular flexibility. The improved emulsification stability is because insoluble aggregates in the emulsion are transformed into soluble aggregates through microwave-metal ion interaction, forming a rigid film that separates the oil and water phases, clearly defining the oil-water interface, preventing oil droplet aggregation, and thus maintaining the overall emulsification stability of the solution.

[0047] Table 1. Characteristics of emulsifying properties and emulsifying stability of wheat germ protein under different treatment conditions.

[0048]

[0049] Example 8

[0050] The lyophilized powder obtained in Example 1 was selected, and the structural properties of wheat germ proteins in each group were analyzed by gel electrophoresis. Specific structures are shown below. Figure 4 As shown in the figure, the first lane is the protein marker, and the other four lanes, from left to right, are the control group, microwave group, metal ion group, and microwave-metal ion group. The electrophoresis results of wheat germ proteins show that the molecular weight of the proteins is distributed below 130 kDa. Five bands and one band range can be clearly distinguished in the figure. Comparison with the protein marker bands reveals that the molecular weights of wheat germ proteins are approximately 115 kDa, 90 kDa, 35 kDa, 34 kDa, 30 kDa, and 17-21 kDa. The molecular weight distribution of proteins in each treatment group is similar. The protein bands in the microwave-metal ion group are slightly lower overall, indicating that the molecular weight of proteins in the microwave-metal ion group is slightly smaller than that in the other three groups. The intensity of the band color reflects the solubility of the protein. It can be seen that protein subunits with a molecular weight of 17-21 kDa exhibit higher solubility in the four extraction solutions. Analysis of the above results suggests that wheat germ proteins are mainly composed of small-molecule proteins, and the increased protein solubility is due to this.

[0051] Example 9

[0052] The microstructure of wheat germ proteins after treatment (control group, microwave group, metal ion group, and microwave-metal ion group) was observed using a scanning electron microscope at 2000x magnification. The results are as follows: Figure 5 As shown. In the control group, wheat germ protein mostly appeared in clumps, tightly stacked together, with irregular shapes and uneven surfaces; Figure 5 b is wheat germ protein after microwave modification. It is obvious that its particles have become looser, its volume has decreased, and its overall structure is more porous. Figure 5 c is wheat germ protein modified with metal ions. Since metal ions form complexes with polypeptides, the wheat germ protein particles under this treatment appear as aggregated clumps, which are likely complexes formed by proteins and metal ions. Moreover, the wheat germ protein particles have irregular shapes and contain a loose and porous structure, which can enhance their water-holding and oil-holding properties to a certain extent. Figure 5 d is wheat germ protein modified by microwave-metal ions. It can be found that some protein particles aggregate into small clusters, while some particles are loose and small in shape. This is because the large protein-metal ion complexes are decomposed by microwave action.

[0053] Example 10

[0054] The lyophilized powder obtained in Example 1 was used to study the secondary structures of wheat germ protein, including β-sheets, random coils, α-helices, and β-turns, using Fourier transform infrared spectroscopy. The absorption peaks for each secondary structure were located in the amide I band, i.e., 1600-1700 cm⁻¹, with β-sheets at 1600-1640 cm⁻¹, random coils at 1640-1650 cm⁻¹, α-helices at 1650-1660 cm⁻¹, and β-turns at 1660-1700 cm⁻¹. First, the infrared spectrum of wheat germ protein was measured in the wavenumber range of 400-4000 cm⁻¹. Wheat germ proteins obtained after different treatments all exhibited essentially consistent absorption peaks, including typical amide band vibrations at 1220-1300 cm⁻¹ (amide III band, C-O and C-N stretching, O=C-N and N-H bending), 1480-1580 cm⁻¹ (amide II band, C-N stretching, N-H bending), 2850-2980 cm⁻¹ (C-H stretching), 1600-1700 cm⁻¹ (amide I band, C=O stretching), and 3000-3500 cm⁻¹ (O-H and N-H stretching). Further analysis was performed using the amide I band spectrum. Figure 6 As shown, the microwave group showed no β-turn absorption peak, but the content of other structures increased, indicating that microwaves unfolded the β-turn structures, exposing more of the other secondary structures. In the metal ion group, all secondary structures were present, but the overall content decreased. This is because metal ions formed complexes with thiol, amino, and hydroxyl groups on the protein surface, disrupting some secondary structures and leading to a decrease in the content of each secondary structure, resulting in a corresponding decrease in absorbance. The microwave-metal ion group showed only one absorption peak, corresponding to random coils, indicating that microwave-metal ion treatment significantly altered the secondary structure of wheat germ protein, producing a large number of random coil structures. This is because microwaves disrupted the β-turn in the tertiary structure, causing the tertiary structure to unfold and producing a large number of α-helices and β-sheet structures. Metal ions then formed complexes with these structures, disrupting these secondary structures and forming more random coils. This structure facilitates the entry of water molecules, enhancing hydration and thus, to some extent, benefiting the protein's water-holding capacity, oil-holding capacity, emulsifying properties, solubility, and foaming properties.

[0055] Example 11

[0056] Repeat the steps of Examples 5-10 to verify the lyophilized powders obtained in Examples 2-4. The solubility, water-holding capacity, oil-holding capacity, emulsifying properties, and structural properties of the wheat germ protein under microwave-metal ion assays were determined. The results are as follows: Figures 8-11 As shown.

[0057] Depend on Figures 8-11It can be seen that the emulsifying properties of the freeze-dried powders obtained in Examples 1 to 4 are all improved, especially the emulsifying properties of Example 1 are significantly enhanced. Therefore, it can be concluded that the wheat germ incubation conditions in Example 1 are the optimal conditions, and the wheat germ protein prepared by the microwave-metal ion group in Example 1 has the best characteristics.

Claims

1. The application of a method in improving the emulsifying properties of wheat germ protein, characterized in that, The method includes the following steps: (1) Mix wheat germ powder with an incubation solution containing metal ions to obtain a mixture; the metal ions include Zn 2+ Mn 2+ or Ca 2+ The Zn 2+ The concentration of Mn is 1.0 mmol / L. 2+ The concentration of Ca was 1.6 mmol / L. 2+ The concentration of the incubator is 1.4 mmol / L; the mass-to-volume ratio of the wheat germ powder to the incubation solution is 1:8~10 g / mL; the pH of the incubation solution is 2.9~3.1; the wheat germ powder is obtained by passing it through a 40~60 mesh sieve. (2) The mixture is microwave-treated and incubated in a water bath to obtain an optimized wheat germ protein homogenate; the microwave treatment power is 400W and the microwave treatment time is 10s.

2. The application according to claim 1, characterized in that, The incubation solution in step (1) also contains 0.08 ~ 0.1 mol / L of citric acid-sodium citrate.

3. The application according to claim 1, characterized in that, The water bath incubation temperature in step (2) is 48~50 ℃, and the time is 5~7 h.

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