Method for improving frozen storage stability of frozen low-salt surimi product

Abstract

The invention belongs to the technical field of surimi products, and discloses a method for improving the freezing storage stability of frozen low-salt surimi products. The method comprises the following steps: S1, adding polysaccharide, sodium chloride and water into fish meat, and chopping to obtain low-salt minced fish; s2, performing sausage filling treatment on the low-salt surimi, and then performing ultrasonic treatment, curing treatment, cooling and freezing storage under a heating condition to obtain frozen low-salt surimi; the polysaccharide is more than one of curdlan, chitosan and kappa-carrageenan; the ultrasonic treatment conditions are as follows: the power of ultrasonic waves is 200-600W, and the ultrasonic treatment time is 10-30 minutes. According to the method disclosed by the invention, under the condition that the salt is reduced by 50%, not only can the gel quality of the low-salt surimi product be improved, but also the quality deterioration caused by temperature fluctuation can be improved, and the freezing storage stability of the frozen low-salt surimi product is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic product processing, and in particular relates to a method for improving the frozen storage stability of frozen low-salt surimi products. Background Art

[0002] As a traditional food with a long history, surimi products are widely circulated in many regions. For example, the long-renowned Chaozhou fish balls and Shandong fish dumplings are representative surimi products in my country. In the processing of traditional surimi products, 3% salt is usually added to promote the dissolution of myofibrillar protein, thereby forming a dense and uniform gel structure. However, excessive intake of sodium chloride can cause a series of health problems, such as chronic diseases such as stroke and hypertension. At the same time, due to the characteristics of high water content and high protein content, surimi products are usually in a frozen storage state before and after market circulation, which can effectively delay the deterioration of food and extend the shelf life. However, it is difficult to avoid temperature fluctuations during market circulation and retail, which causes surimi products to undergo repeated freezing and thawing. The formation and growth of ice crystals during the freezing and thawing process will cause protein denaturation and water loss in surimi products, resulting in the deterioration of the quality of surimi products. The appearance of these phenomena will greatly reduce the acceptance of consumers. Therefore, in order to process greener, healthier and higher-quality foods, reducing the salt content in the surimi products industry while improving the quality deterioration caused by freezing has become an urgent problem to be solved.

[0003] Measures to improve the freeze-thaw stability of frozen low-salt surimi products mainly include the use of physical processing technology or the addition of modifiers of different qualities. Under low-salt conditions, due to the inability of proteins to fully dissolve, a strand-like gel structure will be formed. The low-salt surimi products produced by this method have high water molecule mobility, low gel strength, and poor frozen storage stability. Studies have shown that the rich hydroxyl groups of polysaccharides can bind to water molecules, reduce the formation of ice crystals, help inhibit protein denaturation and slow down protein aggregation. In addition, polysaccharides may enhance the gelation properties of surimi proteins through the formation of hydrogen bonds and electrostatic interactions, which helps to limit the mobility of water molecules and ice crystal growth, further reduce the growth rate of ice crystals and change the morphology of growing ice crystals. When polysaccharides are added alone to low-salt surimi products, the polysaccharides cannot be completely dispersed in the protein system, which is not conducive to the formation of a dense and uniform network structure. As a non-thermal treatment technology, ultrasonic technology has been widely studied in the field of food processing due to its advantages such as no pollution, safety, and simple operation. Studies have shown that the huge energy generated by the cavitation effect of ultrasound is conducive to the dispersion of exogenous additives and the formation of a uniform gel system. Therefore, the present invention utilizes ultrasound to evenly disperse polysaccharides in a protein system, while enhancing the interaction between protein and polysaccharides. The surimi products produced by this method can inhibit the formation and growth of ice crystals and thus improve the frozen storage stability of low-salt surimi products. Summary of the invention

[0004] The present invention provides a method for improving the frozen storage stability of a frozen low-salt fish paste product. The present invention utilizes ultrasound to evenly disperse polysaccharides in the low-salt fish paste, promotes the interaction between protein and polysaccharides, produces a low-salt fish paste product with high gel strength and water holding performance, and significantly improves the frozen storage stability of the low-salt fish paste product.

[0005] In order to achieve the above object, the purpose of the present invention is achieved through the following scheme:

[0006] A method for improving the frozen storage stability of a frozen low-salt surimi product comprises the following steps:

[0007] S1: adding polysaccharide, sodium chloride and water to the fish meat and chopping and mixing to obtain low-salt fish paste;

[0008] S2: subjecting the low-salt surimi to enema treatment, and then subjecting it to ultrasonic treatment under heating conditions, aging treatment, cooling, and frozen storage to obtain frozen low-salt surimi.

[0009] The polysaccharide is one or more of curdlan, chitosan and kappa-carrageenan.

[0010] The heating temperature is 30-50° C., the ultrasonic treatment conditions are as follows: the ultrasonic power is 200-600 W, and the ultrasonic time is 10-30 min.

[0011] The aging conditions are: treating at 80-90° C. for 10-30 min.

[0012] The added amount of the polysaccharide is 0.3-0.9% of the mass of the low-salt fish paste;

[0013] In step S1, the amount of sodium chloride added is 1.5-2.5% of the mass of the low-salt fish paste; the water is ice water, and the amount of ice water added is 80-82% of the mass of the low-salt fish paste.

[0014] The low-salt fish paste in step S1 is obtained specifically by the following method: chopping the fish meat, adding sodium chloride and half of ice water to chop and stir, and then adding polysaccharide and the other half of ice water to continue chopping and stirring.

[0015] The condition of the idle chopping is 800-1500r / min and the idle chopping is 1-5min;

[0016] The chopping and stirring conditions when adding sodium chloride are: 4000-5500r / min chopping and stirring for 4-6min;

[0017] The chopping conditions when adding polysaccharides are: 4000-5500r / min for 2-4min.

[0018] The fish meat in step S1 is prepared from marine fish as raw material through the processes of washing, eviscerating, meat extraction, rinsing and dehydrating.

[0019] The marine fish include sea bass, redwood fish and copper basin fish; the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2-0.5% for 5-20 minutes, and the mass ratio of fish meat to rinsing liquid is 1:4.

[0020] The enema in step S2 is performed at 0-10°C;

[0021] The freezing temperature is -20°C;

[0022] The cooling is cooling at room temperature.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention aims to solve the problem of decreased quality of surimi gel caused by salt reduction, and utilizes the cavitation effect of ultrasound to promote the interaction between protein and polysaccharide, thereby promoting the cross-linking of protein and polysaccharide to form a uniform and dense gel network, thereby producing a surimi product of better quality. The operation process of this method is simple and controllable, which is conducive to mass production.

[0025] (2) The present invention aims to solve the problems of decreased gel strength and water loss of low-salt surimi products during the freeze-thaw process by combining ultrasound and the addition of polysaccharides to produce high-quality surimi products. The low-salt surimi products produced by this method significantly inhibit the quality degradation during the freeze-thaw process and improve the freeze-thaw stability of the low-salt surimi products.

[0026] (3) The surimi products produced by the present invention have higher gel strength and better frozen storage stability than surimi products heated in a water bath. Moreover, the prepared surimi gel can still maintain good gel strength and water holding capacity after multiple freeze-thaw cycles, which provides a practical and powerful basis for developing a green and healthy surimi product market. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a relaxation time diagram of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 without freeze-thaw treatment;

[0028] Figure 2 is a relaxation time diagram of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 after 5 freeze-thaw treatments;

[0029] Figure 3 is a graph of the moisture content of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 before freeze-thaw treatment;

[0030] Figure 4It is a graph showing the moisture content of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 after five freeze-thaw treatments. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto. The materials used in the examples of the present invention can all be purchased commercially.

[0032] Example 1

[0033] A method for improving the frozen storage stability of frozen low-salt surimi products (ultrasound synergistic with curdlan), comprising the following steps:

[0034] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the mass ratio of fish meat to rinsing liquid is 1:4;

[0035] S2: putting the fish meat of step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding curdlan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of curdlan added is 0.6% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0036] S3: Select a polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, and control the temperature during enema below 10°C; then perform ultrasonic treatment on the surimi product at 40°C with an ultrasonic power of 480W for 30 minutes;

[0037] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0038] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0039] Example 2

[0040] A method for improving the frozen storage stability of frozen low-salt surimi products (ultrasound synergistic chitosan), comprising the following steps:

[0041] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the mass ratio of fish meat to rinsing liquid is 1:4;

[0042] S2: putting the fish meat from step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding chitosan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; wherein the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of chitosan added is 0.6% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0043] S3: Select a polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, and control the temperature during enema below 10°C; then perform ultrasonic treatment on the surimi product at 40°C with an ultrasonic power of 480W for 30 minutes;

[0044] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0045] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0046] Example 3

[0047] A method for improving the frozen storage stability of frozen low-salt surimi products (ultrasound synergistic kappa-carrageenan), comprising the following steps:

[0048] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0049] S2: putting the fish meat from step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding κ-carrageenan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; wherein the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of κ-carrageenan added is 0.6% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0050] S3: Select a polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, and control the temperature during enema below 10°C; then perform ultrasonic treatment on the surimi product at 40°C with an ultrasonic power of 480W for 30 minutes;

[0051] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0052] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0053] Example 4

[0054] A method for improving the frozen storage stability of a frozen low-salt surimi product (curdlan), comprising the following steps:

[0055] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0056] S2: putting the fish meat from step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding curdlan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; wherein the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of curdlan added is 0.6% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0057] S3: Select polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, control the temperature during enema below 10°C; then water bath at 40°C for 30 minutes;

[0058] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0059] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0060] Example 5

[0061] A method for improving the frozen storage stability of a frozen low-salt surimi product (chitosan), comprising the following steps:

[0062] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0063] S2: putting the fish meat of step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding chitosan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; wherein the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of chitosan added is 0.6% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0064] S3: Select polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, control the temperature during enema below 10°C; then water bath at 40°C for 30 minutes;

[0065] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0066] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0067] Example 6

[0068] A method for improving the frozen storage stability of a frozen low-salt surimi product (κ-carrageenan), comprising the following steps:

[0069] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0070] S2: putting the fish meat from step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding κ-carrageenan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; wherein the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of κ-carrageenan added is 0.6% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0071] S3: Select polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, control the temperature during enema below 10°C; then water bath at 40°C for 30 minutes;

[0072] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity.

[0073] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0074] Example 7

[0075] A method for improving the frozen storage stability of frozen low-salt surimi products (ultrasound synergistically with curdlan and chitosan), comprising the following steps:

[0076] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0077] S2: putting the fish meat of step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding curdlan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of curdlan added is 0.3% of the weight of the final fish paste, the amount of chitosan added is 0.3% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0078] S3: Select a polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, and control the temperature during enema below 10°C; then perform ultrasonic treatment on the surimi product at 40°C with an ultrasonic power of 480W for 30 minutes;

[0079] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0080] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0081] Example 8

[0082] A method for improving the frozen storage stability of frozen low-salt surimi products (ultrasound synergistically with curdlan, chitosan and kappa-carrageenan), comprising the following steps:

[0083] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0084] S2: putting the fish meat of step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and half of the ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and sticky; then adding curdlan and the other half of the ice water to the completely dispersed fish paste and continuing to chop and mix, the chopping and mixing condition is: 5000r / min chopping and mixing for 3min, to obtain the final fish paste; the amount of sodium chloride added is 1.5% of the weight of the final fish paste, the amount of curdlan added is 0.2% of the weight of the final fish paste, the amount of chitosan added is 0.2% of the weight of the final fish paste, the amount of κ-carrageenan added is 0.2% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0085] S3: Select a polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, and control the temperature during enema below 10°C; then perform ultrasonic treatment on the surimi product at 40°C with an ultrasonic power of 480W for 30 minutes;

[0086] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity;

[0087] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0088] Comparative Example 1

[0089] Production method of low-salt fish paste products:

[0090] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0091] S2: putting the fish meat obtained in step S1 into a high-speed shearing machine for air chopping, the air chopping condition is: 1000r / min air chopping for 2min; then adding sodium chloride and ice water to the fish paste for chopping and mixing, the chopping and mixing condition is: 5000r / min chopping and mixing for 5min, so that the fish paste is completely dispersed and becomes sticky, and the final fish paste is obtained; wherein the amount of sodium chloride added is 1.5% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0092] S3: Select polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, control the temperature during enema below 10°C; then water bath at 40°C for 30 minutes;

[0093] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity.

[0094] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0095] Comparative Example 2

[0096] Preparation method of normal salted fish paste products:

[0097] S1: Using sea bass as raw material, fish paste is obtained through the following process steps: washing, evisceration, meat extraction, rinsing, dehydration, etc.; wherein the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2% for 5 minutes, and the ratio of fish meat to rinsing liquid is 1:4;

[0098] S2: putting the fish meat obtained in step S1 into a high-speed shearing machine for air chopping at a speed of 1000 r / min for 2 min; then adding sodium chloride and ice water to the fish paste for chopping and mixing at a speed of 5000 r / min for 5 min, so that the fish paste is completely dispersed and becomes sticky, thereby obtaining the final fish paste; wherein the amount of sodium chloride added is 3% of the weight of the final fish paste, and the amount of ice water added is 82% of the weight of the final fish paste;

[0099] S3: Select polyvinyl chloride casing with a diameter of 20 mm for artificial enema treatment, control the temperature during enema below 10°C; then water bath at 40°C for 30 minutes;

[0100] S4: The surimi product is matured in a water bath at 90°C for 20 min, and then cooled at room temperature for 4 h after the maturity.

[0101] S5: The surimi product produced in step S4 is frozen and stored at -20°C.

[0102] Effect verification

[0103] The surimi product produced in the embodiment of the present invention was subjected to freeze-thaw cycle treatment, specifically, the surimi gel stored in a refrigerator (-20°C) for 12 hours was completely thawed at 4°C for 8 hours, and this operation process was defined as a freeze-thaw cycle, which was repeated 5 times. The gel quality of the surimi product was then measured and analyzed as follows, including the following steps:

[0104] (1) Gel strength: First, remove the casing and cut the surimi gel into 2 cm high cylinders with smooth and flat cut surfaces. The TA-XT Plus texture analyzer was used for the test. The instrument parameters were set as follows: probe model P / 0.5S, trigger force 5 g, compression deformation 80%, and speed 1.0 mm / s before, during, and after the test.

[0105] (2) Juice loss: The loss of surimi gel was analyzed by measuring the weight difference between surimi gel before and after freeze-thaw cycles. The weight of each surimi gel sample before and after freeze-thaw cycles was recorded, and the juice loss was calculated by the following formula:

[0106]

[0107] Among them, m 1 represents the weight of surimi gel before FT cycle (g), and m 2 The weight (g) of the surimi gel after the FT cycle is shown.

[0108] (3) Determination of whiteness: First, the fish paste gel sample was cut into a size of about 2 cm × 2 cm × 1 cm in length, width and height at the center. Then, a portable colorimeter was used to measure the sample brightness value (L*), red-green value (a*), and yellow-blue value (b*). Three pieces were taken from each sample and each piece was measured three times. Finally, the average value of the measured values ​​was calculated from nine times. The whiteness calculation method of each gel sample is as follows:

[0109]

[0110] (4) Determination of moisture content: First, cut the surimi gel sample into a size of about 2 cm × 2 cm × 1 cm in length, width and height, weigh about 10 g, and place it at room temperature for 30 min to allow the temperature to equilibrate to room temperature. The parameters of the low-field nuclear magnetic resonance analyzer equipment are set as follows: resonance frequency of 21.3 MHz, magnet strength of 0.55 T, coil diameter of 60 m, and magnet temperature of 32 ° C. After placing the sample in the nuclear magnetic resonance tube, the machine is calibrated using Q-FID and standards, and then the sample spin-spin relaxation time signal is collected using the CPMG pulse sequence. The sampling frequency SW is 100kHz, the analog gain RG1 is 28.0dp, the 90° RF pulse width (P1) is 9.00μs, the digital gain DRG1 is 3, the number of sampling points TD is 900002, the gain parameter PRG is 2, the repeated sampling interval TW is 8000ms, the accumulation number NS is 4, the 180° RF pulse width P2 is 18.48μs, the echo time TE is 0.600ms, and the number of echoes NECH is 15000.

[0111] The gel strength, juice loss and whiteness of the fish intestines prepared in Examples 1-8 of the present invention and Comparative Examples 1-2 were measured, and the results are shown in Table 1, Table 2 and Table 3.

[0112] Table 1 Determination results of frozen surimi gel strength

[0113]

[0114] Note: Different letters indicate significant differences between groups of data (P<0.05), capital letters indicate intra-group differences, and lowercase letters indicate inter-group differences.

[0115] As shown in Table 1, compared with Comparative Example 1, the low-salt surimi products produced in Examples 1-8 significantly improved their gel strength. Compared with Comparative Example 2, the low-salt surimi products produced in Examples 1-8 also significantly improved their gel strength. The results show that the low-salt surimi products produced by ultrasound combined with polysaccharide have a more significant effect than adding polysaccharide alone.

[0116] Compared with the untreated fish paste, after 5 freeze-thaw cycles, the gel strength of the fish paste products in Comparative Example 1 and Comparative Example 2 decreased by 26% and 19%, respectively. Compared with the untreated fish paste, after 5 freeze-thaw cycles, the gel strength of the low-salt fish paste products produced in Examples 1-8 decreased less. Compared with Comparative Example 1, the gel strength of the low-salt fish paste products produced in Examples 1-8 decreased less. Compared with Comparative Example 2, the gel strength of the low-salt fish paste products produced in Examples 1-8 decreased less. The results show that the addition of polysaccharides can improve the gel strength of low-salt fish paste, and the effect of ultrasound synergizing polysaccharides is better than the effect of adding polysaccharides alone.

[0117] Table 2 Determination results of frozen surimi gel juice loss

[0118]

[0119]

[0120] Note: Different letters indicate significant differences between groups of data (P<0.05), capital letters indicate intra-group differences, and lowercase letters indicate inter-group differences.

[0121] As shown in Table 2, the juice loss of surimi products increases with the increase in the number of freeze-thaw cycles. After 5 freeze-thaw cycles, the juice loss of Comparative Examples 1-2 increased significantly, while the increase in juice loss of Examples 1-8 was smaller. After 5 freeze-thaw cycles, compared with Comparative Example 1, the increase in juice loss of Examples 1-8 was smaller; compared with Comparative Example 2, the increase in juice loss of Examples 1-8 was smaller. The results show that the addition of polysaccharides can reduce the juice loss of low-salt surimi products in freeze-thaw cycles, and the effect of ultrasound synergizing polysaccharides is better than the effect of adding polysaccharides alone.

[0122] Table 3 Determination results of whiteness of frozen surimi gel

[0123]

[0124] Note: Different letters indicate significant differences between groups of data (P<0.05), capital letters indicate intra-group differences, and lowercase letters indicate inter-group differences.

[0125] As shown in Table 3, before freeze-thaw treatment, the whiteness of the low-salt surimi products produced in Examples 1-8 was significantly reduced compared with Comparative Example 1. The whiteness of the low-salt surimi products produced in Examples 1-8 was also significantly reduced compared with Comparative Example 2. The results show that the addition of polysaccharides has a negative impact on the whiteness of surimi products, while the effect of ultrasonic treatment on the whiteness of surimi products is smaller than that of adding polysaccharides.

[0126] Compared with the untreated fish paste, the whiteness of the fish paste products of Comparative Example 1 and Comparative Example 2 decreased by 6.44% and 5.99% after 5 freeze-thaw cycles. Compared with the untreated fish paste, the whiteness of the low-salt fish paste products produced in Examples 1-8 decreased significantly after 5 freeze-thaw cycles. Compared with Comparative Examples 1 and 2, the decrease in whiteness of the low-salt fish paste products produced in Examples 1-8 was smaller. The results show that the low-salt fish paste products produced by ultrasound combined with polysaccharides can inhibit the decrease in whiteness after multiple freeze-thaw cycles.

[0127] The results of the determination of moisture content of frozen surimi products are as follows: Figures 1 to 4 shown.

[0128] Figure 1 is a relaxation time diagram of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 without freeze-thaw treatment; Figure 2 is a relaxation time diagram of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 after 5 freeze-thaw treatments; Figure 3 is a graph of the moisture content of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 before freeze-thaw treatment; Figure 4 It is a graph showing the moisture content of the surimi products prepared in Examples 1 to 8 and Comparative Examples 1 to 2 after five freeze-thaw treatments.

[0129] Low-field nuclear magnetic resonance technology is a non-destructive and rapid detection technology that can determine the distribution and state of water in food in a short period of time. The relaxation time can directly reflect the mobility and distribution of water molecules in the gel matrix. The longer the relaxation time, the worse the binding ability of hydrogen protons, indicating that the water molecules are less bound and the water is freer. Figure 1 and Figure 2 It can be observed that there are three forms of water in the surimi gel: bound water, immobile water and free water, and the water mainly exists in the surimi product in the form of immobile water. After 5 freeze-thaw cycles, the free water content of the surimi product increased significantly.

[0130] Combination Figure 3 and Figure 4 It can be seen that before freeze-thaw treatment, the free water content in the low-salt surimi products produced in Examples 1-8 was significantly reduced compared with Comparative Example 1; the free water content in the low-salt surimi products produced in Examples 1-8 was also significantly reduced compared with Comparative Example 2. The results show that the addition of polysaccharides can limit the flow of water in surimi products and improve the water holding capacity of surimi products.

[0131] Compared with the untreated fish paste, the free water content of the fish paste products in Comparative Examples 1 and 2 increased significantly after 5 freeze-thaw cycles. Compared with the untreated fish paste, the free water content of Examples 1-8 also increased significantly after 5 freeze-thaw cycles. Compared with Comparative Example 1, the degree of decrease in the free water content of Examples 1-8 was significantly reduced. Compared with Comparative Example 2, the degree of decrease in the free water content of Examples 1-8 was also significantly reduced. The results show that the addition of polysaccharides can reduce the free water content of low-salt fish paste products during freeze-thaw, and the effect of ultrasound synergizing polysaccharides to reduce the free water content of low-salt fish paste products is better than the effect of adding polysaccharides alone.

[0132] In summary, the surimi product prepared by the present invention can improve the frozen storage stability of the frozen low-salt surimi product, and the effect of adding curdlan, chitosan and κ-carrageenan to the low-salt surimi in a ratio of 1:1:1 and ultrasonically treated is better than the effect of adding a single polysaccharide.

[0133] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for improving the frozen storage stability of a frozen low-salt surimi product, characterized in that: The following steps are involved: S1: adding polysaccharide, sodium chloride and water to the fish meat and chopping and mixing to obtain low-salt fish paste; S2: subjecting the low-salt surimi to enema treatment, and then subjecting it to ultrasonic treatment under heating conditions, aging treatment, cooling, and frozen storage to obtain frozen low-salt surimi; the stability of the frozen low-salt surimi is improved after freeze-thawing; The polysaccharide is one or more of curdlan, chitosan and kappa-carrageenan; The heating temperature is 30-50° C., the ultrasonic treatment conditions are as follows: the ultrasonic power is 200-600 W, and the ultrasonic time is 10-30 min.

2. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 1, characterized in that: The added amount of the polysaccharide is 0.3-0.9% of the mass of the low-salt fish paste; The aging conditions are: treating at 80-90° C. for 10-30 min.

3. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 1, characterized in that: In step S1, the amount of sodium chloride added is 1.5-2.5% of the mass of the low-salt fish paste; the water is ice water, and the amount of ice water added is 80-82% of the mass of the low-salt fish paste.

4. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 1, characterized in that: The low-salt fish paste in step S1 is obtained specifically by the following method: chopping the fish meat, adding sodium chloride and half of ice water to chop and stir, and then adding polysaccharide and the other half of ice water to continue chopping and stirring.

5. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 4, characterized in that: The condition of the idle chopping is 800-1500r / min for 1-5min; The chopping and stirring conditions when adding sodium chloride are: 4000-5500r / min chopping and stirring for 4-6min; The chopping conditions when adding polysaccharides are: 4000-5500r / min for 2-4min.

6. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 1, characterized in that: The fish meat in step S1 is prepared from marine fish as raw material through the processes of washing, eviscerating, meat extraction, rinsing and dehydrating.

7. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 6, characterized in that: The marine fish include sea bass, redwood fish and copper basin fish; the rinsing process conditions are: rinsing with a sodium chloride solution with a mass concentration of 0.2-0.5% for 5-20 minutes, and the mass ratio of fish meat to rinsing liquid is 1:

4.

8. The method for improving the frozen storage stability of a frozen low-salt surimi product according to claim 1, characterized in that: The enema is performed at 0-10°C; The freezing temperature is -20°C; The cooling is cooling at room temperature.

Images