Method for preparing myofibrillar protein gel based on low-temperature sol agar
By mixing and gelling myofibrillar protein with low-temperature sol-agar, the problems of insufficient gel strength and high energy consumption caused by traditional heat treatment are solved, realizing the preparation of myofibrillar protein gel with low energy consumption and high efficiency, thereby improving the quality and yield of meat products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIMEI UNIV
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-21
AI Technical Summary
Traditional heat treatment processes often result in insufficient gel strength and poor water retention when preparing myofibrillar protein gels. Furthermore, high-temperature heating increases production energy consumption, affecting the quality and cost of meat products.
The method involves mixing low-temperature sol-agar with myofibrillar proteins and forming a mixed gel through low-temperature melting, thus avoiding structural damage to myofibrillar proteins caused by high temperatures. The process includes preparation, centrifugation to remove air bubbles, water bath cooking, and low-temperature refrigeration.
It significantly reduces gel loss during cooking, protects actin from degradation, maintains gel strength and nutritional properties, and is suitable for processing heat-sensitive meat products, reducing production energy consumption and costs.
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Abstract
Description
Technical Field
[0001] This invention relates to the technical field of food processing, specifically to a method for preparing myofibrillar protein gel based on low-temperature sol-agar. Background Technology
[0002] Meat, as an important component of a balanced diet, is rich in high-quality protein, fat-soluble vitamins, and key trace elements such as iron and zinc. Myofibrillar protein (MP), as the main component of muscle protein, accounts for approximately 55% to 65% of the total muscle protein content and is a key structural protein that determines the quality of meat products. MP is mainly composed of thick and thin filaments made up of myosin and actin. It endows meat products with excellent gelling properties, water-holding capacity, and emulsifying properties, and has a decisive influence on the formation of the three-dimensional gel network and the texture and flavor retention of the final product.
[0003] Gelation is a core functional characteristic of muscle proteins in meat processing, and its formation quality directly affects the texture uniformity, structural integrity, palatability, and shelf-life stability of meat products. Various methods exist for preparing protein gels, among which heat-induced gelation is the most commonly used technique in meat processing due to its simplicity and wide applicability. However, during processing, heat treatment and other processes can easily cause changes in the protein protein (MP) structure, leading to decreased water-holding capacity and meat aging, severely impacting meat product quality. Furthermore, to improve gelation performance, related technologies often employ magnetic field treatment, ultrasonic assistance, and modified plant protein blends. However, these methods either require specialized equipment, increasing production costs, or involve cumbersome processes and poor operational controllability, making it difficult to meet the high-efficiency and low-cost requirements of industrial production. Summary of the Invention
[0004] The present invention aims to at least partially solve one of the technical problems in the above-mentioned technologies, namely, to provide a method for preparing myofibrillar protein gel based on low-temperature sol-agar. This method reduces production energy consumption, avoids the damage of high temperature to the myofibrillar protein structure, provides a better technical solution for meat processing, and has important practical application value.
[0005] Therefore, this invention proposes a method for preparing myofibrillar protein gel based on low-temperature sol-agar, which includes the following steps: Step 1: Prepare myofibrillar protein; Step 2: Disperse the low-temperature sol-agar in a sodium chloride solution and melt it to obtain a low-temperature sol-agar solution; Step 3: Add the low-temperature sol-agar solution to the myofibrillar protein to obtain a mixed sol; Step 4: Centrifuge the mixed sol to remove air bubbles; Step 5: Place the air-bubbly mixed sol in a water bath and cook to form a thermally conductive gel; Step 6: Place the gel at a low temperature overnight to obtain myofibrillar protein gel.
[0006] According to the present invention, a method for preparing myofibrillar protein gel based on low-temperature sol agar is provided. The method utilizes low-temperature sol agar to form a mixed gel with myofibrillar protein. The low-temperature dissolution characteristics of low-temperature sol agar can reduce heating energy consumption, significantly reduce the cooking loss of myofibrillar protein gel, promote myofibrillar protein aggregation, and effectively protect actin from degradation at 78~80℃, without changing the gel strength and in vitro protein digestibility, so that the prepared myofibrillar protein gel is suitable for the processing requirements of heat-sensitive meat products.
[0007] Optionally, in step one, the preparation of the myofibrillar protein includes: mixing and stirring animal muscle tissue with phosphate buffer solution, centrifuging to remove the supernatant, retaining the precipitate, and repeating this operation 2 to 4 times; then mixing the precipitate with sodium chloride solution, filtering, and centrifuging to obtain myofibrillar protein.
[0008] Furthermore, the mass-to-volume ratio of the animal muscle tissue to the phosphate buffer solution is 1:3 to 1:5; the concentration of the phosphate buffer solution is 0.08 M to 0.12 M; and the concentration of the sodium chloride solution is 0.08 M to 0.12 M.
[0009] Optionally, the concentration of the sodium chloride solution in step two is 0.5 M to 0.7 M; the melting temperature is 60℃ to 70℃.
[0010] Optionally, in step three, the concentration of myofibrillar protein in the mixed sol is 19 mg / mL to 21 mg / mL, and the amount of low-temperature sol-agar used is 0.4% to 0.6% of the myofibrillar protein mass.
[0011] Optionally, in step four, the centrifugation speed is 1500 rpm / min to 2500 rpm / min, and the time is 1 min to 3 min.
[0012] Optionally, in step five, the steaming time is 25 min to 35 min, and the steaming temperature is 60℃ to 100℃.
[0013] Optionally, in step six, the overnight refrigeration temperature is 2°C to 6°C.
[0014] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0015] Figure 1 To illustrate the effect of different cooking temperatures on cooking loss of pork myofibrillar protein gels according to embodiments and comparative examples of the present invention. Figure 2 To illustrate the effect of different cooking temperatures on gel strength of pork myofibrillar protein gels according to embodiments and comparative examples of the present invention; Figure 3 To illustrate the effect of different cooking temperatures on SDS-PAGE of pork myofibrillar protein gels according to embodiments and comparative examples of the present invention. Figure 4 To illustrate the effect of different cooking temperatures on the microstructure of pork myofibrillar protein gels according to embodiments and comparative examples of the present invention. Figure 5 To investigate the effect of different cooking temperatures on the digestibility of pork myofibrillar protein gels in the gastrointestinal stage according to embodiments and comparative examples of the present invention. Detailed Implementation
[0016] The technical solution of the present invention is illustrated below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not for limiting the order of the method steps or defining the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.
[0017] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.
[0018] This application is based on the inventor's considerations regarding the following: When preparing myofibrillar protein gels using processes such as heat treatment, there are generally technical defects such as insufficient gel strength and poor water retention. To improve water retention and meat quality issues during MP processing, the industry uses exogenous substances for regulation. Among these, agar, a natural colloid extracted from red algae, is listed as a "generally recognized safe" food additive due to its excellent gelling properties, good stability, and biocompatibility, and is used in meat processing. However, traditional agar has significant process limitations, requiring prolonged heating at temperatures above 95°C (over 30 minutes) to completely melt. This characteristic not only significantly increases production energy consumption but also exacerbates the thermal denaturation and structural damage of myofibrillar proteins, further leading to meat quality deterioration, and limiting its application in heat-sensitive meat products.
[0019] Therefore, this application proposes to use low-temperature sol-agar to prepare myofibrillar protein gel.
[0020] The low-temperature sol agar was purchased from Fujian Green Qilin Food Colloid Co., Ltd.
[0021] Traditional agar was purchased from Fujian Green Qilin Food Colloid Co., Ltd.
[0022] The test materials used in this invention are all common commercial products, which can be purchased on the market or prepared by known methods.
[0023] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.
[0024] Example 1 Step 1, Preparation of myofibrillar protein: Mince pork and mix it with 0.1 M phosphate buffer solution at a mass-to-volume ratio of 1:4. Centrifuge to remove the supernatant, retain the precipitate, and repeat 3 times. Finally, mix the precipitate with 0.1 M sodium chloride solution, filter, and centrifuge to obtain myofibrillar protein.
[0025] Step 2, Preparation of low-temperature sol-agar solution: Disperse low-temperature sol-agar in 0.6 M sodium chloride solution at a ratio of 1:6 (mg:mL) and melt at 70℃ for 10 min to obtain low-temperature sol-agar solution.
[0026] Step 3, Preparation of the mixed sol: The melted low-temperature sol-agar solution described above is added to the myofibrillar protein to obtain the mixed sol. In this mixed sol, the myofibrillar protein concentration is 20 mg / mL. It is determined that 1.5 mL of 0.6 M sodium chloride solution is needed to add to 1 g of myofibrillar protein. Simultaneously, based on the myofibrillar protein content of 0.5%, the amount of low-temperature sol-agar used in Step 2 is determined to be 0.25 mg. Step 4, degassing: Centrifuge the mixed sol obtained in step 3 at 2000 rpm / min for 1-2 min to remove air bubbles.
[0027] Step 5, thermally conductive gel formation: Place the mixed sol after degassing in Step 4 into a water bath and cook for 30 minutes to form a thermally conductive gel. The cooking temperature is set at 60℃~100℃.
[0028] Step 6, Cold Refrigeration and Shaping: Place the gel obtained in Step 5 at 4°C and refrigerate overnight to obtain pork myofibrillar protein gel.
[0029] Comparative Example 1 Step 1, Preparation of myofibrillar protein: Mince pork and mix it with 0.1 M phosphate buffer solution at a mass-to-volume ratio of 1:4. Centrifuge to remove the supernatant, retain the precipitate, and repeat 3 times. Finally, mix the precipitate with 0.1 M sodium chloride solution, filter, and centrifuge to obtain myofibrillar protein.
[0030] Step 2: Disperse myofibrillar protein in 0.6 M sodium chloride solution to obtain myofibrillar protein solution; the concentration of myofibrillar protein is 20 mg / mL, and the volume of 0.6 M sodium chloride solution to be added to 1 g of myofibrillar protein is determined to be 1.5 mL.
[0031] Step 3, degassing: Centrifuge the myofibrillar protein solution obtained in Step 2 at 2000 rpm / min for 1-2 min to remove air bubbles.
[0032] Step 4, thermally conductive gel formation: The myofibrillar protein solution after degassing in Step 3 is placed in a water bath and cooked for 30 minutes to form a thermally conductive gel. The cooking temperature is set at 60℃~100℃.
[0033] Step 5, cold refrigeration and setting: Place the gel obtained in step 4 at 4°C overnight to obtain pork myofibrillar protein gel.
[0034] Comparative Example 2 Step 1, Preparation of myofibrillar protein: Mince pork and mix it with 0.1 M phosphate buffer solution at a mass-to-volume ratio of 1:4. Centrifuge to remove the supernatant, retain the precipitate, and repeat 3 times. Finally, mix the precipitate with 0.1 M sodium chloride solution, filter, and centrifuge to obtain myofibrillar protein.
[0035] Step 2, Preparation of agar solution: Disperse agar in 0.6 M sodium chloride solution at a ratio of 1:6 (mg:mL) and melt at 100℃ for 1 h to obtain agar solution.
[0036] Step 3, Preparation of the mixed sol: The melted agar solution was added to the myofibrillar protein to obtain the mixed sol. The myofibrillar protein concentration in this mixed sol was 20 mg / mL. The required volume of 0.6 M sodium chloride solution to add to 1 g of myofibrillar protein was determined to be 1.5 mL. Based on the myofibrillar protein content of 0.5%, the amount of agar used in Step 2 was determined to be 0.25 mg. Step 4, degassing: Centrifuge the mixed sol obtained in step 3 at 2000 rpm / min for 1-2 min to remove air bubbles.
[0037] Step 5, thermally conductive gel formation: Place the mixed sol after degassing in Step 4 into a water bath and cook for 30 minutes to form a thermally conductive gel. The cooking temperature is set at 60℃~100℃.
[0038] Step 6, Cold Refrigeration and Shaping: Place the gel obtained in Step 5 at 4°C and refrigerate overnight to obtain pork myofibrillar protein gel.
[0039] Test case The properties of the pork myofibrillar protein gels obtained in Example 1 and Comparative Examples 1-2 were determined.
[0040] (1) Determination of cooking loss Record the mass m1 of the empty centrifuge tube and the mass m2 of the centrifuge tube after adding a certain amount of sol. Simultaneously, record the mass m3 of the centrifuge tube after cooling at 4℃ for 12 hours following cooking. Then, use a small spoon to separate the gel sample from the centrifuge tube, place it on filter paper for 10 minutes, and wait for all the liquid to drain. Finally, place the gel sample back into the centrifuge tube. The cooking loss is calculated using the following formula:
[0041] Where: m1 is the mass of the centrifuge tube (g); m2 is the total mass of the sample and centrifuge tube before cooking; m3 is the total mass of the sample and centrifuge tube after water removal.
[0042] The results are as follows Figure 1 As shown, at 58℃~60℃ and 78℃~80℃, the cooking loss of the pork myofibrillar protein gel in Example 1 was significantly lower than that in Comparative Example 1 and Comparative Example 2. At 98℃~100℃, the cooking loss of the pork myofibrillar protein gel in Example 1 was not significantly different from that in Comparative Example 1 and Comparative Example 2. This indicates that preparing pork myofibrillar protein gel using low-temperature sol-agar can effectively reduce the cooking loss of the gel and improve its water-holding capacity.
[0043] (2) Determination of gel strength After removing the gel samples from the refrigerator and allowing them to stand at room temperature for 30 minutes, the gel strength was determined using a texture analyzer. The texture analyzer parameters were set as follows: test mode was compression mode; compression distance was 12 mm; initial speed was 2 mm / s; test speed was 1 mm / s; post-test speed was 2 mm / s; trigger force was 3 g; and the maximum sustained force was the gel strength.
[0044] The results are as follows Figure 2 As shown, the gel strength of Example 1 is comparable to that of Comparative Example 2 and Comparative Example 1, indicating that the pork myofibrillar protein gel of Example 1 does not affect the gel strength while reducing cooking loss at 58℃~60℃ and 78℃~80℃.
[0045] (3) SDS-PAGE The protein gel and 5% SDS solution were mixed and homogenized at a ratio of 1:9, heated at 85°C for 1 h, and then centrifuged at 10,000 g for 20 min. The supernatant was diluted with loading buffer to 2 mg / mL to prepare total protein electrophoresis samples. The protein / loading buffer mixture was heated in a boiling water bath for 5 min to completely denature the proteins, and 10 μL of sample was added to each well of the electrophoresis gel. Electrophoresis was run at 120 V for 120 min. After electrophoresis, the gel was stained with G-250 Coomassie Brilliant Blue for 30 min and then destained.
[0046] The results are as follows Figure 3 As shown, at a cooking temperature of 78℃~80℃, the actin band in Example 1 was darker and wider than the bands in Comparative Examples 1 and 2, indicating that low-temperature sol-agar can protect the actin of myofibrils from degradation due to temperature.
[0047] (4) Microstructure The gel samples were fixed with 2.5% glutaraldehyde solution for 24 h, cut into cubes with smooth surfaces of approximately 2 mm, washed with phosphate buffer solution (0.1 mol / L KH₂PO₄, pH 6.0) for 1 h, and then dehydrated with a gradient of ethanol (50%, 70%, 90%, and 100% ethanol concentrations) for 30 min at each concentration, followed by displacement with tert-butanol for 30 min, repeated three times. The samples were then frozen at -20°C for 48 h and freeze-dried at -70°C for 48 h.
[0048] The results are as follows Figure 4 As shown, the microstructure of the gels in Comparative Examples 1 and 2 is mainly loose filaments, while that in Example 1 is mainly aggregates, indicating that low-temperature sol-agar promotes the aggregation of myofibrillar proteins.
[0049] (5) Determination of protein digestibility in vitro After in vitro digestion of the gel, the enzymes were inactivated in a boiling water bath for 10 min, followed by centrifugation at 8000 rpm for 10 min to obtain the supernatant and precipitate. The precipitate was dissolved in 5% SDS solution, and the protein content was determined using the BCA method. The protein digestibility was calculated using the following formula: ; Where: M1 is the protein weight (g) of the gel before digestion; W1 is the protein content (mg / g) of the gel before digestion; M2 is the protein weight (g) of the undigested gel after digestion; and W2 is the protein content (mg / g) of the undigested gel after digestion.
[0050] The results are as follows Figure 5 As shown, it can be found that Example 1 has no significant effect on the in vitro digestibility of proteins compared with Comparative Examples 1 and 2. This indicates that the addition of low-temperature sol-agar reduces cooking losses without altering the nutritional characteristics of myofibrillar proteins.
[0051] In summary, according to embodiments of the present invention, the application of low-temperature sol-agar in the preparation of pork myofibrillar protein gel expands the application field of low-temperature sol-agar. Compared with traditional agar, low-temperature sol-agar melts at 60℃~70℃, significantly reducing production energy consumption and avoiding damage to the myofibrillar protein structure caused by high temperatures, thus solving the core pain point of traditional agar in meat processing. This method can significantly reduce the cooking loss of pork myofibrillar protein gel under cooking conditions of 60℃~80℃, promote myofibrillar protein aggregation, protect actin from temperature degradation at 78℃~80℃, and at the same time, not change the nutritional characteristics and gel strength of myofibrillar protein, thereby improving the quality and yield of meat products. Compared with existing methods for improving the performance of myofibrillar protein gel, the present invention does not require additional special equipment such as magnetic fields or ultrasound, nor does it require complex modification of additives. The process is simple, convenient to operate, and low in cost, making it easier to promote and apply industrially.
[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.
[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A method for preparing myofibrillar protein gel based on low-temperature sol-agar, characterized in that, Includes the following steps: Step 1: Prepare myofibrillar protein; Step 2: Disperse the low-temperature sol-agar in a sodium chloride solution and melt it to obtain a low-temperature sol-agar solution; Step 3: Add the low-temperature sol-agar solution to the myofibrillar protein to obtain a mixed sol; Step 4: Centrifuge the mixed sol to remove air bubbles; Step 5: Place the air-bubbly mixed sol in a water bath and cook to form a thermally conductive gel; Step 6: Place the gel at a low temperature overnight to obtain myofibrillar protein gel.
2. The method as described in claim 1, characterized in that, In step one, the preparation of the myofibrillar protein includes: mixing and stirring animal muscle tissue with phosphate buffer solution, centrifuging to remove the supernatant, retaining the precipitate, and repeating this operation 2 to 4 times; then mixing the precipitate with sodium chloride solution, filtering, and centrifuging to obtain myofibrillar protein.
3. The method as described in claim 2, characterized in that, The mass-to-volume ratio of the animal muscle tissue to the phosphate buffer solution is 1:3 to 1:5; the concentration of the phosphate buffer solution is 0.08 M to 0.12 M; and the concentration of the sodium chloride solution is 0.08 M to 0.12 M.
4. The method as described in claim 1, characterized in that, The concentration of the sodium chloride solution in step two is 0.5 M to 0.7 M; the melting temperature is 60℃ to 70℃.
5. The method as described in claim 1, characterized in that, In step three, the concentration of myofibrillar protein in the mixed sol is 19 mg / mL to 21 mg / mL, and the amount of low-temperature sol-agar used is 0.4% to 0.6% of the myofibrillar protein mass.
6. The method as described in claim 1, characterized in that, In step four, the centrifugation speed is 1500 rpm / min to 2500 rpm / min, and the time is 1 min to 3 min.
7. The method as described in claim 1, characterized in that, In step five, the steaming time is 25 min to 35 min, and the steaming temperature is 60℃ to 100℃.
8. The method as described in claim 1, characterized in that, In step six, the overnight refrigeration temperature is 2℃~6℃.