Myofibrillar protein emulsion filling gel as well as preparation method and application thereof

Abstract

The invention provides myofibrillar protein emulsion filling gel as well as a preparation method and application thereof, and relates to the field of foods. The preparation method comprises the following steps: diluting myofibrillar protein to obtain a myofibrillar protein solution, adding genipin into the myofibrillar protein solution for reaction to obtain a reaction solution, performing ultrasonic treatment on the reaction solution to obtain an ultrasonic treatment solution, mixing the ultrasonic treatment solution with vegetable oil, and performing high-speed homogenization to obtain a finished product. The oil-in-water emulsion with stable myofibrillar protein is obtained; and mixing the myofibrillar protein-stabilized oil-in-water emulsion with myofibrillar protein to obtain a mixed sol, and heating and cooling the mixed sol to obtain the emulsion-filled gel. The gel is filled with the emulsion constructed by adopting an ultrasonic-assisted crosslinking technology, so that the texture and lubrication characteristics of the gel are remarkably improved, and the method has great potential in directional design of emulsified products required by different people.

Description

Technical Field

[0001] The invention relates to the field of food, and in particular to a myofibrillar protein emulsion-filled gel and a preparation method and application thereof. Background Art

[0002] Emulsion-filled gel is a soft solid system formed by filling an emulsion into a gel matrix, which combines the beneficial properties of hydrophobic materials and hydrogels. Based on the good amphiphilicity of emulsion-filled gel, it can be used to develop fat substitutes and as a carrier for the controlled release of active substances, as well as for the targeted design of specific food structures.

[0003] For the emulsified meat industry, the use of vegetable oils with a high proportion of unsaturated fatty acids to replace saturated animal fats has become an effective method and research hotspot in reducing chronic diseases such as obesity, cardiovascular disease, and diabetes. However, during the fat replacement process, the fluidity and susceptibility to oxidation of vegetable oils seriously affect the stability of the emulsion, thereby limiting the development of emulsified meat products. The protein-based emulsion-filled gel can replace animal fat and be used in meat products. It can well simulate the hardness and water retention capacity of animal fat, which can not only make low-fat products have similar sensory properties to full-fat products, but also improve the functional characteristics of the product, which has positive significance for the processing of low-fat meat products.

[0004] Myofibrillar protein (MP) is the most abundant protein in muscle and plays a vital role in determining the quality of meat products. It has excellent emulsifying and gelling properties, making it a universal ingredient for preparing stable emulsions and elastic gels in various emulsified meat products. However, due to the tight and complete structure of myofibrillar protein, its solubility and dispersibility are relatively poor, resulting in uneven filling distribution of emulsion-filled gels prepared directly using myofibrillar protein, fragile gel network, relatively poor texture and oil retention, and a heavy greasy feeling after the gel network collapses, which also leads to a rough taste.

[0005] How to overcome the defects of poor texture and taste of emulsion-filled gel based on myofibrillar protein has become an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art emulsion-filled gel based on myosin, such as poor texture properties and poor taste, thereby providing a new myosin emulsion-filled gel and its preparation method and application.

[0007] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for preparing a myofibrillar protein emulsion-filled gel, comprising the following steps: (1) diluting myofibrillar protein to obtain a myofibrillar protein solution, adding genipin to the myofibrillar protein solution for reaction to obtain a reaction solution, ultrasonically treating the reaction solution to obtain an ultrasonically treated solution, mixing the ultrasonically treated solution with vegetable oil, and homogenizing at high speed to obtain a stable oil-in-water emulsion of myofibrillar protein; (2) The myofibrillar protein-stabilized oil-in-water emulsion is mixed with myofibrillar protein to obtain a mixed sol, and the mixed sol is heated and cooled to obtain an emulsion-filled gel.

[0008] Furthermore, in step (1), Dilute myofibrillar protein with phosphate buffer; The phosphate buffer contained 0.6 M NaCl, 20 mM Na 2 HPO 4 / NaH 2 PO 4 , pH = 6.0; The protein concentration in the myofibrillar protein solution is 9.0-12.0 mg / mL, preferably 10.0 mg / mL.

[0009] Furthermore, in step (1), The ratio of genipin to protein in the myofibrillar protein solution is 0.4-0.8 μM / mg, preferably 0.5 μM / mg; The reaction temperature is 25-28 °C, and the reaction time is 3.5-5 h, preferably 4 h; The ultrasonic treatment temperature is 8-15 °C, preferably 10 °C, the power is 300 W, and the time is 10 min.

[0010] Furthermore, in step (1), The ultrasonic treatment liquid and the vegetable oil are mixed in a volume ratio of 4:1; The vegetable oil includes at least one of linseed oil, soybean oil and sunflower oil; The speed of high-speed homogenization was 10000 r / min, the time was 1 min, and the number of times was 2 times.

[0011] Furthermore, in step (2), The protein concentration of the myofibrillar protein is 60-100 mg / mL, preferably 70-80 mg / mL; The protein concentration in the mixed sol is 35.0-50.0 mg / mL, preferably 40.0 mg / mL.

[0012] Furthermore, in step (2), The heating is water bath heating, and the heating conditions are to increase the temperature from 18-22°C to 78-85°C at a rate of 2-4°C / min, and keep the temperature at 78-85°C for 18-25 min. Preferably, the heating conditions are to increase the temperature from 20°C to 80°C at a rate of 2°C / min, and keep the temperature at 80°C for 20 min. The cooling step is transferring the mixture to 3-6°C and storing it for 10-16 hours. Preferably, the cooling step is transferring the mixture to 4°C and storing it for 12 hours.

[0013] Furthermore, the method for extracting myofibrillar protein includes: removing the fascia attached to chicken breast meat and chopping the chicken breast meat into chicken mince; extracting the chicken mince in turn with a standard extraction solution and a low-salt solution to obtain myofibrillar protein.

[0014] Furthermore, the standard extraction solution contains 0.1 M NaCl, 10 mM Na 3 PO 4 , 1 mM EGTA, 2 mM MgCl 2 , pH = 7.0; The low salt solution is 0.1 M NaCl solution; The steps of extracting with the standard extraction solution include: adding 4 times the volume of the standard extraction solution to the chicken paste, homogenizing at 8000 r / min for 1 min, filtering the homogenate, refrigerating centrifuging at 2000 × g, 4°C for 10 min, collecting the precipitate, and repeating the extraction 1 to 2 times; The steps of low-salt solution extraction include: adding 4 times the volume of 0.1 M NaCl solution to the precipitate obtained by extraction with the standard extraction solution, homogenizing at 8000 r / min for 1 min, adjusting the pH value of the homogenate to 6.25 with 0.1 M HCl, refrigerated centrifuging at 2500 × g, 4°C for 10 min, collecting the precipitate, and obtaining myofibrillar protein.

[0015] In a second aspect, the present invention provides a myofibrillar protein emulsion-filled gel obtained by the preparation method.

[0016] In a third aspect, the present invention provides the use of the myofibrillar protein emulsion filling gel obtained by the preparation method in the preparation of emulsified meat products.

[0017] The technical solution of the present invention has the following advantages: The present invention firstly performs ultrasound-assisted cross-linking modification on myofibrillar protein, and the modified protein is used as an emulsifier to form a stable water-in-oil emulsion with vegetable oil, and then the emulsion is filled into a high-concentration protein matrix. Finally, the mixed protein sol is heated to gel, thereby constructing an emulsion-filled gel with good texture and lubrication properties.

[0018] At present, there is a lack of targeted solutions to improve the texture and taste of meat protein emulsion-filled gels. The present invention starts from the perspective of improving the filling phase for the first time. On the basis of ultrasound-assisted cross-linking modified proteins, an emulsion is constructed and filled into the gel matrix. The prepared gel presents an ordered and dense network structure, which can effectively avoid the greasy feeling caused by the collapse of the gel network. The gel has high elasticity and support, can resist large deformation, and it is unexpectedly found that it can significantly reduce the friction coefficient after simulating oral processing, has a good lubrication effect, and is conducive to improving the taste of gel products. Therefore, filling the gel with an emulsion constructed by ultrasound-assisted cross-linking technology significantly improves the texture and lubrication properties of the gel, and has great potential in the directional design of emulsified products that meet the needs of different groups of people.

[0019] The prior art can improve the gel-forming ability of meat protein to a certain extent by performing ultrasonic treatment during the thermally induced gel formation process of myofibrillar protein, but the high-temperature water bath synergistic ultrasound method is not conducive to maintaining the original nutrition of the gel protein and has certain negative effects. The present application adopts ultrasound-assisted cross-linking means to first construct a stable pre-emulsion, and then fill the emulsion into the gel and then perform conventional water bath heating, which can effectively avoid the negative effects of high-temperature water bath synergistic ultrasound and is conducive to maintaining the original nutrition of the gel protein. In addition, the present application does not require specific heating equipment in the process of preparing the gel, and ordinary water bath heating can prepare a gel with good texture and lubrication properties, which has the advantages of simple operation and cost-effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 1 is a microscopic structure diagram of the emulsion-filled gel prepared in the embodiment of the present invention and comparative examples 1 to 3; Figure 2 It is a frequency scanning diagram of the emulsion-filled gel prepared in the embodiment of the present invention and comparative examples 1 to 3; Figure 3Graphs showing creep properties of the emulsion-filled gels prepared in Examples of the present invention and Comparative Examples 1 to 3; Figure 4 : is the elastic Lissajous curve of the emulsion-filled gel prepared in the embodiment of the present invention and comparative examples 1 to 3; Figure 5 : is the viscosity Lissajous curve of the emulsion-filled gel prepared in the embodiment of the present invention and comparative examples 1 to 3; Figure 6 It is the Stribeck curve obtained by sliding friction of the emulsion-filled gel prepared in the embodiment of the present invention and comparative examples 1 to 3 after simulated oral processing. DETAILED DESCRIPTION

[0022] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0023] The solution formulas involved in the embodiments are as follows: Phosphate buffer contains 0.6 M NaCl, 20 mM Na 2 HPO 4 / NaH 2 PO 4 , pH = 6.0; The standard extraction solution contained 0.1 M NaCl, 10 mM Na 3 PO 4 , 1 mM EGTA, 2 mM MgCl 2 , pH = 7.0; The low salt solution is 0.1 M NaCl solution.

[0024] The myofibrillar protein used in the embodiment was extracted as follows: The fascia attached to the chicken breast was removed and the chicken breast was chopped into minced meat; 4 volumes of standard extraction solution were added to the minced chicken, homogenized at 8000 r / min for 1 min, the homogenate was filtered with double gauze, and centrifuged at 2000 × g, 4 °C for 10 min, the precipitate was collected, and the extraction was repeated twice; 4 volumes of low salt solution were added to the precipitate obtained by extraction with the standard extraction solution, homogenized at 8000 r / min for 1 min, the pH value of the homogenate was adjusted to 6.25 with 0.1 M HCl, and centrifuged at 2500 × g, 4 °C for 10 min, the precipitate was collected, and myofibrillar protein (protein concentration 70 mg / mL) was obtained.

[0025] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the art can be used. The raw materials or instruments used are all conventional products that can be obtained commercially, including but not limited to the raw materials or instruments used in the examples of this application.

[0026] Example This embodiment provides a method for preparing a myofibrillar protein emulsion-filled gel, and the specific steps are as follows: (1) The extracted myofibrillar protein was diluted with phosphate buffer to a protein concentration of 10.0 mg / mL, and genipin was added to the obtained myofibrillar protein solution (genipin was added according to the ratio of genipin to protein in the myofibrillar protein solution of 0.5 μM / mg), and the reaction was carried out at 25°C for 4 h to obtain a reaction solution, and the reaction solution was ultrasonically treated at 10°C and 300 W for 10 min to obtain an ultrasonically treated solution, and the ultrasonically treated solution was mixed with linseed oil at a volume ratio of 4:1, and high-speed homogenization was carried out at 10000 r / min for 1 min, and the mixture was repeated twice to obtain a stable water-in-oil emulsion of myofibrillar protein; (2) The myofibrillar protein-stabilized oil-in-water emulsion was mixed with the extracted myofibrillar protein in a ratio of 1:1 (mL / g) to obtain a mixed sol with a protein concentration of 40.0 mg / mL. The mixed sol was heated in a water bath from 20 °C to 80 °C at a rate of 2 °C / min, and kept at 80 °C for 20 min. It was then transferred to 4 °C and refrigerated for 12 h to obtain an emulsion-filled gel.

[0027] Comparative Example 1 This comparative example provides a method for preparing a myofibrillar protein gel, and the specific steps are as follows: The extracted myofibrillar protein was diluted with phosphate buffer to a protein concentration of 40.0 mg / mL, and the myofibrillar protein solution was heated in a water bath from 20°C to 80°C at a rate of 2°C / min, and kept at 80°C for 20 minutes, and then transferred to 4°C for refrigeration and storage for 12 hours to obtain myofibrillar protein gel.

[0028] Comparative Example 2 This comparative example provides a method for preparing a myofibrillar protein emulsion-filled gel, and the specific steps are as follows: (1) The extracted myofibrillar protein was diluted with phosphate buffer to a protein concentration of 10.0 mg / mL, and the obtained myofibrillar protein solution was mixed with linseed oil at a volume ratio of 4:1. The mixture was homogenized at 10,000 r / min for 1 min, and the mixture was repeated twice to obtain an oil-in-water emulsion. (2) The oil-in-water emulsion was mixed with the extracted myofibrillar protein to obtain a mixed sol with a protein concentration of 40.0 mg / mL. The mixed sol was heated in a water bath from 20 °C to 80 °C at a rate of 2 °C / min, and kept at 80 °C for 20 min. The mixed sol was then transferred to 4 °C and refrigerated for 12 h to obtain an emulsion-filled gel.

[0029] Comparative Example 3 This comparative example provides a method for preparing a myofibrillar protein emulsion-filled gel, and the specific steps are as follows: (1) The extracted myofibrillar protein was diluted with phosphate buffer to a protein concentration of 10.0 mg / mL, and genipin was added to the obtained myofibrillar protein solution (genipin was added according to the ratio of genipin to protein in the myofibrillar protein solution of 0.5 μM / mg), and the reaction was carried out at 25°C for 4 h to obtain a reaction solution, and the reaction solution was mixed with linseed oil at a volume ratio of 4:1, and high-speed homogenization was performed at 10,000 r / min for 1 min, and repeated twice to obtain an oil-in-water emulsion; (2) The oil-in-water emulsion was mixed with the extracted myofibrillar protein (protein concentration 70-80 mg / mL) to obtain a mixed sol with a protein concentration of 40.0 mg / mL. The mixed sol was heated in a water bath from 20 °C to 80 °C at a rate of 2 °C / min, and kept at 80 °C for 20 min. It was then transferred to 4 °C and refrigerated for 12 h to obtain an emulsion-filled gel.

[0030] Experimental Example 1 Microstructure of Gel 1. Experimental methods: The structure of the emulsion-filled gel was observed using a cryogenic scanning electron microscope (Cryo-SEM) (Quanta 450, FEI Ltd., USA), and the microscopic morphological images of the gel were obtained at 1600× and 6000× at an accelerating voltage of 10 kV.

[0031] 2. Experimental results: like Figure 1 As shown, the protein gel sample in Comparative Example 1 presents a porous network structure, while the emulsion-filled gel samples in Example and Comparative Examples 2-3 present microspherical protrusions, indicating that the emulsion droplets are well embedded in the gel network. Compared with Comparative Examples 2 and 3, the microspherical protrusions of the samples in the Example group are relatively small and present an ordered and dense network structure, indicating that the protein emulsion constructed by ultrasound-assisted cross-linking can be more evenly dispersed into the gel pores, which helps to improve the texture quality of the gel.

[0032] Experimental Example 2 Texture characteristics of gel 1. Experimental methods: The textural properties of the gels (1 cm in diameter and height) were determined using a texture analyzer (TA. XT. Plus, Stable microsystem, Surrey, UK) and measured using a P50 probe. The measurement parameters were set to 5 mm / s before the test, 1 mm / s during the test, 5 mm / s after the test, 75% strain, and 5 g force.

[0033] 2. Experimental results: Table 1 Changes in hardness, adhesiveness and chewiness of different gels

[0034] As shown in Table 1, compared with the protein gel sample in Comparative Example 1, the hardness, adhesiveness, and chewiness of the latex-filled gel samples in Example 1 and Comparative Examples 2-3 were improved, indicating that the latex droplets can fill the pores of the gel network and play a supporting role, which is consistent with the microstructure results in Experimental Example 1 ( Figure 1 ). Compared with the comparative examples 2 and 3, the hardness, stickiness and chewiness of the samples in the embodiment group were significantly improved, which further showed that the protein emulsion constructed by ultrasound-assisted cross-linking can be effectively filled into the protein matrix to achieve the effect of supporting the gel structure and improving the quality of the gel texture.

[0035] Experimental Example 3 Rheological properties of gel 1. Experimental methods: The rheological properties of the gels were measured using a parallel-plate (50 mm diameter, 1 mm gap) rotational rheometer (Anton Paar, Physica MCR302e, Austria).

[0036] 1. Frequency scan: The frequency of the sample was swept from 0.1 rad / s to 10 rad / s with a strain of 1%. The power law model was used to fit the storage modulus (G') and loss modulus (G''), calculated as follows:

[0037] where K' and K'' are power law model constants related to gel strength, and n' (dimensionless) and n'' (dimensionless) are frequency exponents.

[0038] 2. Creep determination: A stress of 1 Pa was applied to the sample for 3 minutes and then released for 3 minutes. The creep recovery rate was calculated as follows:

[0039] Among them, 𝛾 T and 𝛾 p are the total strain and the recovery strain, respectively.

[0040] Burger's model is used to fit the creep compliance curve of the sample, and the formula is as follows:

[0041] in, J (1 / Pa) is the instantaneous compliance, G and G They are Hook elastic modulus (instantaneous) and Voigt elastic modulus (delayed), τ is the delay time (seconds), μ 0 is the viscous modulus (Pa-seconds).

[0042] 3. Large amplitude shear test ( Large amplitude oscillation shear , LAOS): Strain sweeps from 0.01% to 1000% amplitude were recorded at a frequency of 1 Hz to characterize the LAOS behavior of the samples. Raw data of stress and strain waveforms were collected, and the nonlinear response was analyzed using the MITlaos program when the samples were selected at 1%, 10%, 40%, 100%, 400% and 1000% oscillatory strains.

[0043] 2. Experimental results: 1. Frequency scan: like Figure 2 As shown, the G' of the latex-filled gel samples in the embodiment and comparative examples 2-3 is higher than that of the protein gel sample in comparative example 1, indicating that the latex-filled gel can strengthen the internal structure and enhance the reverse deformation ability. Compared with comparative examples 2-3, the G' of the sample in the embodiment group is the highest, which is attributed to the protein latex constructed by ultrasound-assisted cross-linking being able to effectively interact with the protein matrix to form a gel with high elasticity.

[0044] In order to more accurately evaluate the viscoelastic properties of the gel, the frequency sweep data were fitted.

[0045] Table 2 Changes in frequency scan fitting parameters for different gels

[0046] As shown in Table 2, compared with the protein gel sample of Comparative Example 1, the emulsion-filled gel samples of Example 1 and Comparative Examples 2 to 3 have K The value increased significantly (P<0.05). n The value was significantly reduced (P<0.05) and close to zero, indicating that the latex-filled gel is an elastic dominant material. K' and K'' Higher value, n' and n''The value is lower, which indicates that the gel structure of the example group is stronger and the frequency dependence is weaker.

[0047] 2. Creep characteristics: like Figure 3 As shown, the strain value of the protein gel sample in Comparative Example 1 is higher. This is because the pure protein gel has a porous network structure and does not have the ability to resist external forces, making the gel more easily deformed under the influence of external forces. Compared with the samples in Comparative Example 1, the strain values ​​of the latex-filled gel samples in the examples and comparative examples 2-3 are significantly reduced. After the stress is eliminated, the strain recovery rate of the gel is significantly higher than that in the comparative example 1 group (P<0.05). Among them, the strain value of the example group is the lowest and the recovery rate is the highest, indicating that the latex prepared by ultrasound-assisted cross-linking can enhance the gel structure.

[0048] Table 3 Changes in fitting parameters of creep recovery behavior of different gels

[0049] The viscoelastic Burgers type in Table 3 can well describe the creep properties of the gel. By calculation, compared with the comparative example 1, the addition of the latex in the embodiment and the comparative examples 2 to 3 can improve the creep properties of the gel. G , G and μ 0 value, reduce τ The value indicates that the gel structure is enhanced and the viscoelastic behavior is enhanced. Among them, the sample in the embodiment group has the highest G , G , μ 0 Value, lowest τ The values ​​indicate that the emulsion-filled gel prepared based on the protein emulsion constructed by ultrasound-assisted cross-linking has high elasticity and high recovery.

[0050] 3. Large amplitude shear test: like Figure 4 As shown in the figure, when the strain is 1% to 100%, the curve deformation of the embodiment group is slower than that of other groups, indicating that the latex-filled gel sample of the embodiment group has a strong ability to resist deformation. When the strain exceeds 100%, the shape of the elastic Lissajous curve of the embodiment group changes significantly, indicating that the latex-filled gel of the embodiment group has high brittleness under large deformation. Figure 5 As shown, in the viscosity Lissajous curve, when the strain exceeds 100%, a secondary ring is observed in the embodiment group, indicating that the gel structure is disentangled. The above results further show that the latex-filled gel in the embodiment group has high elastic material properties and also has brittleness under high strain, and can be used to design food materials that meet the needs of specific groups of people.

[0051] Experimental Example 4 Tribological Properties of Gel 1. Experimental methods: The samples were mixed and crushed with artificial saliva in a volume ratio of 4:1 and incubated at 37 °C for 30 min to simulate oral processing, and then the oral lubrication properties of the emulsion-filled gel were determined by sliding friction. The emulsion-filled gel was tribologically tested using a soft TA-Tribometer (STAT) with a soft probe ball and a sliding gasket. The friction coefficient (μ, unitless) was obtained based on the sliding speed from 0.01 mm / s to 9 mm / s when loaded with 0.049 N at 37 °C (±1 °C). The tribological properties of the gel were calculated according to the following formula:

[0052] where F and W are the measured friction force and the loading force of 0.049 N (5.0 g), respectively.

[0053] Data processing: The above experimental operation was repeated three times and expressed as mean ± standard deviation. SPSS26.0 software was used for one-way analysis of variance and Duncan test to obtain significant differences (P < 0.05).

[0054] 2. Experimental results: like Figure 6 As shown, the pure gel sample of Comparative Example 1 exhibits a higher friction coefficient during the entire sliding process, while compared with Comparative Example 1, the emulsion filling of the Example and Comparative Examples 2-3 can significantly reduce the friction coefficient of the gel after oral processing, indicating that the emulsion helps to improve the lubricity of the gel. Among the Example and Comparative Examples 2-3, the Example group has the lowest friction coefficient at different friction rates, indicating that the emulsion-filled gel sample of the Example group has a good lubrication effect. In addition, as the friction rate increases, the friction coefficient gradually decreases, further indicating that the Example group can effectively lubricate the contact surface, which is beneficial to improving the taste of the sample.

[0055] In summary, the emulsion is constructed on the basis of ultrasound-assisted cross-linked modified protein and filled into the gel matrix. The prepared gel presents an ordered and dense network structure, which can effectively avoid the greasy feeling caused by the collapse of the gel network. The gel has high elasticity and support, can resist large deformation, and can significantly reduce the friction coefficient after simulated oral processing, has a good lubricating effect, and is conducive to improving the taste of the gel product. Compared with the emulsion prepared by filling the myofibrillar protein without any modification (Comparative Example 2) or the emulsion prepared by filling the myofibrillar protein only with biological cross-linking treatment (Comparative Example 3), the emulsion constructed by the ultrasound-assisted cross-linking technology in the present invention significantly improves the texture and lubrication properties of the gel, and has great potential in the directional design of emulsified products for different populations.

[0056] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing a myofibrillar protein emulsion-filled gel, characterized in that: The following steps are involved: (1) diluting myofibrillar protein to obtain a myofibrillar protein solution, adding genipin to the myofibrillar protein solution for reaction to obtain a reaction solution, ultrasonically treating the reaction solution to obtain an ultrasonically treated solution, mixing the ultrasonically treated solution with vegetable oil, and homogenizing at high speed to obtain a stable oil-in-water emulsion of myofibrillar protein; (2) The myofibrillar protein-stabilized oil-in-water emulsion is mixed with myofibrillar protein to obtain a mixed sol, and the mixed sol is heated and cooled to obtain an emulsion-filled gel.

2. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 1, characterized in that: In step (1), Dilute myofibrillar protein with phosphate buffer; The phosphate buffer contains 0.6 M NaCl, 20 mM Na2HPO4 / NaH2PO4, pH = 6.0; The protein concentration in the myofibrillar protein solution is 9.0-12.0 mg / mL, preferably 10.0 mg / mL.

3. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 1, characterized in that: In step (1), The ratio of genipin to protein in the myofibrillar protein solution is 0.4-0.8 μM / mg, preferably 0.5 μM / mg; The reaction temperature is 25-28 °C, and the reaction time is 3.5-5 h, preferably 4 h; The ultrasonic treatment temperature is 8-15 °C, preferably 10 °C, the power is 300 W, and the time is 10 min.

4. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 1, characterized in that: In step (1), The ultrasonic treatment liquid and the vegetable oil are mixed in a volume ratio of 4:1; The vegetable oil includes at least one of linseed oil, soybean oil and sunflower oil; The speed of high-speed homogenization was 10000 r / min, the time was 1 min, and the number of times was 2 times.

5. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 1, characterized in that: In step (2), The protein concentration of the myofibrillar protein is 60-100 mg / mL, preferably 70-80 mg / mL; The protein concentration in the mixed sol is 35.0-50.0 mg / mL, preferably 40.0 mg / mL.

6. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 1, characterized in that: In step (2), The heating is water bath heating, and the heating conditions are to increase the temperature from 18-22°C to 78-85°C at a rate of 2-4°C / min, and keep the temperature at 78-85°C for 18-25 min. Preferably, the heating conditions are to increase the temperature from 20°C to 80°C at a rate of 2°C / min, and keep the temperature at 80°C for 20 min. The cooling step is transferring the mixture to 3-6°C and storing it for 10-16 hours. Preferably, the cooling step is transferring the mixture to 4°C and storing it for 12 hours.

7. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 1, characterized in that: The method for extracting myofibrillar protein comprises: removing fascia attached to chicken breast meat and chopping the chicken breast meat into chicken mince; extracting the chicken mince in sequence with a standard extraction solution and a low-salt solution to obtain myofibrillar protein.

8. The method for preparing the myofibrillar protein emulsion-filled gel according to claim 7, characterized in that: The standard extraction solution contained 0.1 M NaCl, 10 mM Na3PO4, 1 mM EGTA, 2 mM MgCl2, pH = 7.0; The low salt solution is 0.1 M NaCl solution; The steps of extracting with the standard extraction solution include: adding 4 times the volume of the standard extraction solution to the chicken paste, homogenizing at 8000 r / min for 1 min, filtering the homogenate, refrigerating centrifuging at 2000 × g, 4°C for 10 min, collecting the precipitate, and repeating the extraction 1 to 2 times; The steps of low-salt solution extraction include: adding 4 times the volume of 0.1 M NaCl solution to the precipitate obtained by extraction with the standard extraction solution, homogenizing at 8000 r / min for 1 min, adjusting the pH value of the homogenate to 6.25 with 0.1 M HCl, refrigerated centrifuging at 2500 × g, 4°C for 10 min, collecting the precipitate, and obtaining myofibrillar protein.

9. The myofibrillar protein emulsion-filled gel obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the myofibrillar protein emulsion-filled gel obtained by the preparation method according to any one of claims 1 to 8 in the preparation of emulsified meat products.

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