Method for improving gel quality of skipjack surimi by using vegetable protein
By adding an appropriate amount of plant protein to skipjack tuna surimi, a stable three-dimensional network structure is formed, which solves the problems of insufficient gel strength and water retention of skipjack tuna surimi, and realizes the high-quality application and efficient utilization of skipjack tuna surimi.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-28
- Publication Date
- 2026-04-14
AI Technical Summary
During processing, skipjack tuna surimi has poor gel network formation, resulting in poor gel strength and water retention due to the high activity of endogenous proteases in the muscle. This limits its application in high-quality surimi products.
By adding different types and amounts of plant proteins (soy protein isolate, peanut protein, and rice protein) to bonito surimi and through specific processing techniques such as chopping, moisture adjustment, and heat setting, a stable three-dimensional network structure is formed, thereby improving gel quality.
It significantly improves the gel strength, water retention and textural properties of skipjack tuna surimi gel, expands the application scenarios of skipjack tuna surimi, meets the human body's need for essential amino acids, and gives surimi products a better taste and flavor.
Smart Images
Figure CN121845202A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of surimi processing technology, and in particular to a method for improving the gel quality of skipjack tuna surimi using plant protein. Background Technology
[0002] Surimi gel products are a type of processed seafood product that combines nutritional value and convenience. With their delicate texture, rich animal protein content, and wide range of consumption scenarios, they occupy an important position in the food industry. They are widely used in the production of fish balls, fish cakes, and simulated crab meat.
[0003] Skipjack tuna is a pelagic migratory fish widely distributed in temperate and tropical seas worldwide. It boasts advantages such as abundant resources, rapid growth, and relatively low fishing costs. Its muscle is rich in high-quality animal protein, with a high content of myofibril protein, and its amino acid composition meets the essential amino acid requirements of the human body, making it a raw material with significant development potential in the aquatic product processing industry. Currently, skipjack tuna is mainly used to make traditional products such as canned goods and dried fish, resulting in a relatively simple processing method and generating a large amount of by-products, leading to low resource utilization. Processing skipjack tuna into surimi can effectively increase its added value, achieve efficient resource utilization, and meet consumers' demand for diversified aquatic foods. However, during the processing of skipjack tuna surimi, the high activity of endogenous proteases in the muscle easily leads to protein degradation, disrupting gel network formation and resulting in poor gel strength and water retention. This limits the application of skipjack tuna surimi in high-quality surimi products. Therefore, it is necessary to improve its gel quality and enhance the processing and utilization value of skipjack tuna resources by adding exogenous functional substances.
[0004] Plant proteins are widely available, inexpensive, and rich in nutrients, containing essential amino acids and possessing excellent water-holding, oil-holding, and gelling properties. Compared to animal proteins, plant proteins have advantages in resource sustainability and cost control, and their functional properties can be optimized by controlling processing techniques to suit the application needs of different food systems.
[0005] Soy protein isolate is a high-purity legume protein with excellent gelling, emulsifying, and water-holding properties. It can interact with other components in food systems to form a stable three-dimensional network structure, thereby improving the texture and taste of the product. Peanut protein is a highly nutritious oilseed protein resource. It not only has a relatively complete amino acid composition, containing all eight essential amino acids for the human body, but also has good emulsifying, gelling, water-holding, and rheological properties, which can enhance the stability of surimi systems and reduce the loss of water and fat during processing. Rice protein is a new type of high-quality cereal protein resource with low allergenicity, good solubility and digestibility. The human body can utilize more than 80% of its protein, and it is chemically stable, does not easily denature during processing, and can better retain its nutrients.
[0006] Different types of plant proteins have varying effects on the gel quality of surimi due to differences in their molecular structure and functional properties. Furthermore, the content of plant protein added is a key process parameter; excessively high or low levels can lead to poor improvement (e.g., low content fails to form an effective network structure, while high content easily results in a rough texture). Therefore, this study systematically investigates the effects of different types and amounts of plant proteins on the gel quality of specific surimi raw materials, clarifies their mechanisms of action and optimal application conditions, and promotes the efficient application of plant proteins in surimi processing. Summary of the Invention
[0007] In view of this, this application provides a method for improving the quality of skipjack tuna surimi gel using plant protein. Using skipjack tuna as raw material and suitable plant protein as a modifier, the method improves the quality of skipjack tuna surimi gel. This fully utilizes the resource advantages of skipjack tuna and the cost and functional advantages of plant protein, while also solving the problem of insufficient quality of traditional skipjack tuna surimi gel. This increases the added value of skipjack tuna processing and provides a new technical reference for the development of the aquatic food industry. It can effectively overcome the defects of the existing technology.
[0008] The first aspect of this application provides a method for improving the quality of skipjack tuna surimi gel using plant protein, comprising the following steps:
[0009] Skipjack tuna meat is sequentially chopped, salted, mixed with plant protein, and its moisture content is adjusted at a temperature of 4-10℃ to obtain a mixed fish paste. The mixed fish paste is then filled into a mold, heated to set, and then cooled to room temperature with ice water to obtain a fish paste gel.
[0010] Preferably, the preparation process of the bonito meat is as follows: using frozen bonito meat as raw material, the bonito meat is obtained by thawing, cutting into pieces, and rinsing.
[0011] Preferably, the preparation process of the bonito meat is as follows: after the bonito frozen to -20℃ is thawed at 4℃ for 10 hours, the skin, bones and internal organs are removed, the fish meat is cut into small pieces of 3 cm × 3 cm × 3 cm, and rinsed with clean water three times for 10 to 15 minutes each time. Finally, it is dehydrated to obtain bonito meat.
[0012] Preferably, the specific process of the air chopping is as follows: the bonito meat is chopped in a meat grinder at a speed of 3000~5000 r / min, and after each chopping for 30 seconds, it is paused for 15 seconds until 3 minutes of chopping is obtained to obtain bonito slurry.
[0013] Preferably, the specific process of salt grinding is as follows: based on the weight of the bonito surimi, add 2.5% salt to the hollow-cut bonito surimi and continue salt grinding for 2 minutes.
[0014] Preferably, the specific process of adding plant protein and mixing is as follows: based on the weight of bonito surimi, 1%, 2%, 4%, and 6% of plant protein powder are added to the salted bonito surimi, respectively. The plant protein powder is added evenly in batches every 30 seconds, and the mixture is chopped. The chopper speed is 3000~5000 r / min. After each 30-second chopping, the mixture is paused for 15 seconds until it has been chopped for 2 minutes. After each addition of plant protein powder, chopping must continue to ensure that the plant protein powder is evenly mixed with the bonito surimi. The plant protein powder is selected from at least one of soy protein isolate, peanut protein, and rice protein.
[0015] Preferably, the specific process of adjusting the moisture content is as follows: ice water is added to the bonito slurry after mixing and chopping with added plant protein, and the moisture content is measured using a moisture meter. The moisture content is adjusted to 80%, and then chopped at a chopper speed of 3000~5000 r / min. Each chopping session lasts 30 seconds, followed by a 15-second pause, until 1 minute of chopping is completed.
[0016] Preferably, the heating and shaping process is as follows: a two-stage heating and shaping method is adopted, wherein the first stage heating temperature is 40℃ and the time is 60min; the second stage heating temperature is 90℃ and the time is 30min.
[0017] A second aspect of this application also provides a surimi product obtained by the above-described method. Specifically, the obtained surimi product is stored in a refrigerator at 4°C.
[0018] The third aspect of this application also provides the application of the above-described method for improving the gel quality of bonito surimi using plant protein in bonito food processing.
[0019] Compared with the prior art, this application has the following advantages:
[0020] (1) This application significantly improves the gel strength, water holding capacity, hardness, and other textural properties of surimi gel by adding soy protein isolate, peanut protein, and rice protein, as well as different amounts (1%, 2%, 4%, and 6%) of these proteins to skipjack tuna surimi. Experiments show that different proteins and different amounts have different effects on the properties of surimi gel, resulting in surimi gels with better performance in terms of structure and texture. This achieves a targeted improvement in the quality of skipjack tuna surimi gel, producing higher-quality skipjack tuna surimi products, which helps to expand the application scenarios of skipjack tuna surimi and improve the comprehensive utilization rate of skipjack tuna.
[0021] (2) By adding three kinds of plant proteins of different types and amounts to the fish paste gel, this application can, on the one hand, make up for the lack of specific amino acids in the bonito fish meat protein and solve the problem of unbalanced amino acid composition of single bonito fish paste protein, thereby meeting the human body's needs for essential amino acids; on the other hand, it can also make the prepared fish paste gel have the unique flavor of plant protein.
[0022] (3) This application compares the effects of different types and contents of plant proteins on the quality of specific surimi gels. By adding an appropriate amount of plant protein to promote protein cross-linking, the gel properties such as strength, texture and water retention of surimi gels can be improved, solving the problems of insufficient strength and poor water retention of existing skipjack surimi gels. This provides technical support for the development of high-quality skipjack surimi products and has broad application prospects. It also provides theoretical basis and reference for the application of different plant proteins in surimi products. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 The bar chart shows the effect of different types and contents of plant proteins on the gel strength of skipjack tuna surimi in Examples 1-12 and Comparative Example 1.
[0025] Figure 2 The bar chart shows the effect of different types and contents of plant proteins on the water-holding capacity of skipjack tuna surimi gel in Examples 1-12 and Comparative Example 1.
[0026] Figure 3The effects of different types and amounts of plant proteins on the moisture distribution of skipjack tuna surimi gel in Examples 1-12 and Comparative Example 1 are shown. A represents the spin-spin relaxation time (T2) with different amounts of soy protein isolate added; B represents the spin-spin relaxation time (T2) with different amounts of soy protein isolate added; C represents the spin-spin relaxation time (T2) with different amounts of soy protein isolate added; and D represents the area ratio of various water peaks.
[0027] Figure 4 The figures are line graphs showing the effects of different types and amounts of plant protein on the rheological properties of skipjack tuna surimi in Examples 1-12 and Comparative Example 1. Figure A shows the effect of adding different amounts of soy protein isolate (SPI) on the rheological properties of skipjack tuna surimi, Figure B shows the effect of adding different amounts of peanut protein (PP) on the rheological properties of skipjack tuna surimi, and Figure C shows the effect of adding different amounts of rice protein (RP) on the rheological properties of skipjack tuna surimi. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0029] Unless otherwise specified, the experimental methods used in the embodiments of this application are all conventional methods.
[0030] In the following examples and comparative examples, unless otherwise specified, all raw materials can be prepared by commercial purchase or conventional methods.
[0031] Example 1
[0032] The method for improving the quality of skipjack tuna surimi gel using plant protein in this embodiment includes the following steps:
[0033] Skipjack tuna frozen to -20°C was thawed at 4°C for 10 hours. The skin, bones, and viscera were removed, and the resulting fish meat was cut into 3 cm × 3 cm × 3 cm pieces. The pieces were then rinsed three times with clean water for 10-15 minutes each time, and finally dehydrated to obtain skipjack tuna chunks. The chunks were then placed in a blender and chopped for 3 minutes (the blender speed was 3000-5000 r / min, with a 15-second pause after each 30-second chopping, until a total of 3 minutes of chopping was achieved) to obtain skipjack tuna paste. Based on the mass of the paste (200g), 2.5% salt was added after the initial chopping, and the mixture was further salted and pounded for 2 minutes to obtain salted skipjack tuna paste. Based on the fish paste weight, weigh out 1% soy protein isolate and add it evenly to the mixer every 30 seconds. Mix and chop with the fish paste for 2 minutes (chopper speed 3000~5000 r / min, pause for 15 seconds after each 30-second chopping, until 2 minutes of chopping). Ensure that the mixing is thorough after each addition of soy protein isolate. Add ice water to the mixed fish paste to adjust the moisture content to 80%, and continue chopping for 1 minute (chopper speed 3000~5000 r / min, pause for 15 seconds after each 30-second chopping, until 1 minute of chopping). Then, fill the resulting mixed fish paste into a mold and shape it. Perform a two-stage heating and setting process: first, heat in a water bath at 40℃ for 60 minutes, then heat in a water bath at 90℃ for 30 minutes to obtain a thermoformed mixed fish paste gel. Finally, the gel was cooled to room temperature in ice water and stored in a 4°C refrigerator, referred to as 1% SPI.
[0034] Example 2
[0035] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 1, except that the amount of soy protein isolate added is 2%, and the resulting gel is referred to as 2%SPI.
[0036] Example 3
[0037] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 1, except that the amount of soy protein isolate added is 4%, and the resulting gel is referred to as 4%SPI.
[0038] Example 4
[0039] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 1, except that the amount of soy protein isolate added is 6%, and the resulting gel is referred to as 6%SPI.
[0040] Example 5
[0041] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 1, except that 1% soy protein isolate is replaced with 1% peanut protein, and the resulting gel is referred to as 1%PP.
[0042] Example 6
[0043] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 5, except that the amount of peanut protein added is 2%, and the resulting gel is referred to as 2%PP.
[0044] Example 7
[0045] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 5, except that the amount of peanut protein added is 4%, and the resulting gel is referred to as 4%PP.
[0046] Example 8
[0047] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 5, except that the amount of peanut protein added is 6%, and the resulting gel is referred to as 6%PP.
[0048] Example 9
[0049] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Embodiment 1, except that 1% soy protein isolate is replaced with 1% rice protein, and the resulting gel is referred to as 1%RP.
[0050] Example 10
[0051] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 9, except that the amount of rice protein added is 2%, and the resulting gel is referred to as 2%RP.
[0052] Example 11
[0053] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 9, except that the amount of rice protein added is 4%, and the resulting gel is referred to as 4%RP.
[0054] Example 12
[0055] The method for improving the quality of bonito surimi gel using plant protein provided in this embodiment can be referred to in Example 9, except that the amount of rice protein added is 6%, and the resulting gel is referred to as 6%RP.
[0056] Comparative Example 1
[0057] The method for improving the quality of skipjack tuna surimi gel in this comparative example includes the following steps:
[0058] Skipjack tuna frozen to -20°C was thawed at 4°C for 10 hours. The skin, bones, and viscera were removed, and the resulting fish meat was cut into 3 cm × 3 cm × 3 cm pieces. The pieces were rinsed three times with clean water for 10-15 minutes each time, and then dehydrated to obtain skipjack tuna chunks. These chunks were then placed in a blender and chopped for 3 minutes (3000-5000 rpm, pausing for 15 seconds after each 30-second chopping cycle, repeated until a total of 3 minutes was achieved) to obtain skipjack tuna paste. Using 200g of paste as a baseline, 2.5% salt was added after the initial chopping, and the paste was further salted and pounded for 2 minutes to obtain salted skipjack tuna paste. Ice water was added to the paste to adjust the moisture content to 80%, and the paste was chopped for 1 minute (3000-5000 rpm, pausing for 15 seconds after each 30-second chopping cycle, repeated until a total of 1 minute was achieved). After the fish paste obtained from chopping is filled into a mold and shaped, it undergoes a two-stage heating and setting process: first, it is heated in a water bath at 40°C for 60 minutes, and then heated in a water bath at 90°C for 30 minutes to obtain a thermoformed mixed fish paste gel. After cooling to room temperature in ice water, it is stored in a refrigerator at 4°C, referred to as 0%.
[0059] Test case
[0060] The resulting surimi gels from the examples and comparative examples were compared as follows:
[0061] The gels prepared in Examples 1-12 and Comparative Example 1 were subjected to water retention tests, gel strength determination (GB / T36187-2024), texture property determination, moisture distribution determination, and rheological property determination.
[0062] Water-holding capacity (WHC) determination: The sample was cut into small pieces, and the fish paste gel was weighed and recorded as M1. Then, the fish paste gel was wrapped in three layers of filter paper and inserted into a 50 mL centrifuge tube. Subsequently, it was centrifuged at 5000 g for 15 min, and the sample was wiped dry and recorded as M2.
[0063] WHC (%) = M2 / M1 × 100
[0064] Gel strength determination: The sample was cut into cylinders with a diameter of 2.5 cm and a height of 2 cm, and the gel strength was measured under specific parameters. The experimental parameters were set as follows: P / 0.25S probe, trigger force 5 g; pre-test speed, post-test speed, and test speed were all 1.0 mm / s; probe penetration distance was 15 mm.
[0065] Texture testing: Select the P / 36R metal spherical probe and set the parameters as follows: pre-test speed, 2 mm / s; test speed, 1 mm / s; post-test speed, 2 mm / s; strain, 40%; trigger force, 5 g.
[0066] Moisture distribution test: The moisture distribution and composition of the surimi products were tested using a low-field nuclear magnetic resonance spectrometer. The transverse relaxation time T2 of the gel was determined using a Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence. The measurement parameters were set as follows: SW = 200 kHz, RG1 = 10, P1 = 7 us, DRG1 = 3, TD = 800054, PRG = 1, TW = 2500 ms, NS = 4, P2 = 13.04 s, TE = 0.5, NECH = 8000. Each sample was repeated three times.
[0067] Rheological property testing: A 60 mm plate was used. The sample was first uniformly coated onto the testing platform. The test parameters were: frequency 0.1 Hz, strain 2.0%, upper and lower slits 1 mm, initial temperature 25℃, heating rate 5℃ / min, and final temperature 90℃. During the measurement, a layer of silicone oil was applied to seal the areas of the fish paste in contact with air. The changes in stored modulus energy / dissipated modulus energy versus temperature were obtained. Each treatment group was measured in triplicate.
[0068] The mixed gels prepared in Examples 1-12 and Comparative Example 1 were tested, and the test results are as follows:
[0069] The gel strength of the examples and comparative examples was measured. The gel strength of fish paste with different types and contents of plant protein was as follows: Figure 1 As shown in the figure, gel strength is an important indicator reflecting the gel performance of composite surimi. Compared with Comparative Example 1, the addition of three plant proteins to skipjack tuna surimi significantly improved the gel strength of all groups except the 6% RP group (P < 0.05), indicating that the type and concentration of protein directly affect the gel strength of surimi. When the addition amounts of SPI, PP, and RP reached 2%, 4%, and 2%, respectively, the gel strength of each group reached its maximum value. The added plant proteins played multiple roles in the system, acting as fillers to fill the gaps in the gel network, as binders to enhance the binding force between protein molecules, and as co-gelling agents to participate in the gel formation process, ultimately promoting the degree of interconnection between protein chains, making the gel network structure more compact, and thus exhibiting higher gel strength. However, with the increase of plant protein concentration, the surimi gel strength gradually decreased. The main reason is that the excessive addition of exogenous plant protein to the surimi diluted the concentration of myofibrillar protein in the surimi matrix, leading to a decrease in surimi gel strength. Different plant proteins have different effects on improving gel strength, which may be due to the different physicochemical properties of the plant proteins themselves.
[0070] The texture of the surimi gels in the examples and comparative examples was determined. The textures of mixed gels with different types and amounts of plant proteins are shown in Table 1. Texture characteristics are a core determining factor of surimi gel product quality and directly affect the final quality performance of the product. Simulated chewing tests were conducted on the surimi gels to obtain TPA parameters, namely hardness, elasticity, cohesiveness, adhesiveness, and chewiness. Table 1 shows that compared with Comparative Example 1, the elasticity and cohesiveness of the surimi gel group with the addition of three plant proteins changed less, while the hardness, chewiness, and adhesiveness showed a trend of first increasing and then decreasing. When the protein concentration is low, the added protein can be uniformly dispersed between the surimi myofibrillar proteins, filling the tiny gaps in the surimi network through hydrogen bonds and hydrophobic interactions, thus improving the density of the surimi gel. When the protein concentration is high, excessive plant proteins accumulate in the surimi system, hindering the normal aggregation and cross-linking of the surimi myofibrillar proteins, thereby leading to a decrease in hardness, chewiness, and adhesiveness. The addition of 2% SPI, 4% PP, and 2% RP resulted in the highest gel hardness for the surimi, and this trend perfectly mirrored the change in gel strength. Overall, the SPI-added group exhibited the highest gel hardness, chewiness, and adhesiveness, followed by the PP group. In the surimi gel system, compared to the other two proteins, SPI more effectively fills the gel network and binds unbound free water, thus laying the foundation for improved gel performance.
[0071] Table 1. Texture properties of fish paste gel by different types and amounts of plant proteins.
[0072]
[0073] The water-holding properties of mixed gels containing different types and amounts of plant proteins are as follows: Figure 2As shown in the figure, the water-holding capacity of surimi gel is a key indicator of its three-dimensional protein network's water-locking ability. Experiments revealed that with increasing amounts of the three plant proteins, the water-holding capacity of the surimi gel initially increased and then stabilized. This is because the addition of plant proteins helps balance the stretching and aggregation rates of surimi protein molecules during the pre-gelation stage, resulting in tighter binding during the thermal gelation process. This balance facilitates the formation of a uniform and stable large-pore three-dimensional network structure, which can firmly adsorb water molecules within the protein, ultimately leading to a more uniform texture in the surimi gel. Excessive plant protein filling the spaces between surimi proteins causes phase separation, inhibits the formation of chemical forces between adjacent myosin molecules, disrupts gel integrity, and reduces water-holding capacity. Among the three plant proteins, the SPI group exhibited the best water-holding capacity. Compared to the other two proteins, SPI has better solubility, hydrophilicity, and abundant amino acid surface charges, allowing it to dissolve more uniformly in the surimi gel, tightly bind and lock in water molecules within the system, and construct a more compact and ordered network structure.
[0074] Moisture distribution of mixed gels with different types and concentrations of plant protein added in different proportions, as shown in the figure. Figure 3 As shown.
[0075] Water distribution is a key indicator characterizing the degree of binding between surimi protein molecules and water molecules; its changes directly reflect differences in water flowability within the gel system. Figure 3 As shown in (A, B, C), the surimi gel system yielded three peaks after NMR fitting. The water content is represented by the peak area corresponding to the curve, and the relaxation times are denoted as T21, T22, and T23, respectively. The results are as follows: Figure 3 As shown in (A, B, C), relaxation time T21 is between 0.1 ms and 10 ms, representing bound water in the surimi system; relaxation time T22 is between 10 ms and 100 ms, representing immobile water in the surimi; and relaxation time T23 is between 100 ms and 1000 ms, representing free water in the surimi. The peak areas of the three relaxation groups show that immobile water accounts for the largest proportion, followed by free water, and bound water is the least. Figure 3(D) It can be seen that, compared with the control group, the addition of the three plant proteins increased the proportion of fixed and bound water and decreased the proportion of free water in the surimi gel, indicating that the addition of the three plant proteins can restrict water flow. Studies have shown that the addition of exogenous proteins increases the protein content in the surimi gel, forming a higher-density microstructure, locking more water in the gel network, thereby reducing the water flow of the surimi gel system and increasing the water binding efficiency. Simultaneously, it was observed that the SPI group, PP group, and RP group exhibited the optimal water distribution state with the highest proportion of non-flowing water and the lowest proportion of free water at addition amounts of 2%, 2%, and 4%, respectively. A small amount of plant protein can fill the pores of the surimi network by absorbing water, thereby reducing water loss from the surimi; however, when excessive plant protein is added, it competes with myofibril proteins for water outside the surimi matrix. This not only hinders the cross-linking process of the surimi gel but also leads to a loose gel network structure, ultimately increasing the proportion of free water.
[0076] Rheological diagrams of mixed gels with different types and proportions of plant protein are shown below. Figure 4 As shown. The storage modulus (G'), also known as the elastic modulus, and the loss modulus (G'), also known as the viscous modulus, of skipjack tuna surimi during the cooking process were measured using a rheometer. Figure 4 It can be seen that the trends of G' and G” changes in all surimi gel groups are roughly the same, with G' always greater than G”. Surimi gels are mainly characterized by elastic modulus, and the G' and G” of surimi gels with added plant proteins are both greater than those of the blank group, indicating that the addition of the three plant proteins is beneficial to the formation of the gel structure of surimi proteins. Secondly, the SPI group, PP group, and RP group reach their maximum modulus at high concentrations of 2%, 4%, and 2%, respectively. When the protein addition reaches 6%, the effect on modulus is not significant and is even lower than that of the blank group, indicating that an appropriate amount of plant protein has an increasing effect on surimi gel, while excessive amounts will hinder the interaction between surimi protein molecules, leading to a decrease in gel viscoelasticity. Among the three plant proteins, SPI is higher, which may be because SPI has stronger gelling ability and better solubility, enabling it to interact with surimi proteins to form a more stable and compact three-dimensional gel network, thus resulting in a higher modulus.
[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A method for improving the quality of skipjack tuna surimi gel using plant protein, characterized in that, Includes the following steps: Skipjack tuna meat is sequentially chopped, salted, mixed with plant protein, and its moisture content is adjusted at a temperature of 4-10℃ to obtain a mixed fish paste. The mixed fish paste is then filled into a mold, heated to set, and then cooled to room temperature with ice water to obtain a fish paste gel.
2. The method for improving the gel quality of skipjack tuna surimi using plant protein according to claim 1, characterized in that, The preparation process of the bonito meat is as follows: frozen bonito meat is used as raw material, and the bonito meat is obtained by thawing, cutting into pieces and rinsing.
3. The method for improving the quality of skipjack tuna surimi gel using plant protein according to claim 2, characterized in that, The preparation process of the bonito meat is as follows: after the bonito frozen to -20℃ is thawed at 4℃ for 10 hours, the skin, bones and internal organs are removed, the fish meat is cut into small pieces of 3 cm × 3 cm × 3 cm, and rinsed with clean water three times, each time for 10 to 15 minutes. Finally, it is dehydrated to obtain bonito meat.
4. The method for improving the gel quality of skipjack tuna surimi using plant protein according to claim 1, characterized in that, The specific process of the air chopping is as follows: the bonito meat is chopped in a meat grinder at a speed of 3000~5000 r / min, and after each chopping for 30 seconds, it is paused for 15 seconds until it is chopped for 3 minutes to obtain bonito paste.
5. The method for improving the quality of skipjack tuna surimi gel using plant protein according to claim 4, characterized in that, The specific process of salt grinding is as follows: based on the weight of the bonito surimi, add 2.5% salt to the bonito surimi after it has been hollowed out, and continue salt grinding for 2 minutes.
6. The method for improving the quality of skipjack tuna surimi gel using plant protein according to claim 5, characterized in that, The specific process of adding plant protein and mixing is as follows: Based on the weight of bonito surimi, 1%, 2%, 4%, and 6% plant protein powder are added to the salted bonito surimi, respectively. The plant protein powder is added evenly in batches every 30 seconds, and the mixture is chopped. The chopper speed is 3000~5000 r / min. After each 30-second chopping, the mixture is paused for 15 seconds until it has been chopped for 2 minutes. After each addition of plant protein powder, chopping must continue to ensure that the plant protein powder is evenly mixed with the bonito surimi. The plant protein powder is selected from at least one of soy protein isolate, peanut protein, and rice protein.
7. The method for improving the quality of skipjack tuna surimi gel using plant protein according to claim 6, characterized in that, The specific process for adjusting the moisture content is as follows: ice water is added to the bonito slurry after mixing and chopping with added plant protein, and the moisture content is measured using a moisture meter. The moisture content is adjusted to 80%, and then chopped at a chopper speed of 3000~5000 r / min. Each chopping session lasts 30 seconds, followed by a 15-second pause, until 1 minute of chopping is completed.
8. The method for improving the quality of skipjack tuna surimi gel using plant protein according to claim 7, characterized in that, The specific process of heating and shaping is as follows: a two-stage heating and shaping method is adopted, wherein the first stage heating temperature is 40℃ and the time is 60min; the second stage heating temperature is 90℃ and the time is 30min.
9. A surimi product, characterized in that, Surimi products prepared by the method according to any one of claims 1 to 8.
10. The application of the method for improving the gel quality of bonito surimi using plant protein according to any one of claims 1 to 8 in bonito food processing.