Fresh-keeping method of squids

Abstract

The invention discloses a fresh-keeping method of squids, and relates to the technical field of fresh-keeping of marine products. The specific preparation method comprises the following steps: firstly, adding the modified sugar, the organic salt, the inorganic salt and the solvent into the solvent, and mixing to obtain the preservative; washing the squids, cutting carcass parts into slices, soaking the squids in a preservative, taking out the squids after soaking, draining the squids, and storing the drained squids at low temperature. The fresh-keeping method for the squids is simple and easy to implement, complex equipment is not needed, the squids treated through the method contain high salt-soluble protein, the water holding capacity of the squids is high, the original quality of the squids can be effectively kept, and the shelf life of the squids is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of seafood preservation, and in particular to a squid preservation method. Background Art

[0002] Squid, as a high-protein, low-fat aquatic product, meets the nutritional needs of modern life. Squid generally needs to be frozen after being salvaged. Aquatic products that are frozen and then stored can effectively delay the decline in product quality and extend the shelf life. During the frozen storage process, temperature fluctuations, protein oxidation and fish water loss will affect the quality of the product. Adding preservatives to aquatic products can effectively prevent protein denaturation and extend the shelf life of squid. Ordinary preservatives have a single performance and their preservation effects have certain limitations. Composite preservatives are one of the main directions of current preservative research, but there is still little research on the preservation effect of composite preservatives on frozen squid. In order to improve the quality and storage period of squid, it is becoming increasingly important to seek preservation technologies that maintain the original quality of squid meat. Summary of the invention

[0003] The invention aims to provide a squid preservation method to solve the problems of squid quality degradation in the existing squid preservation method.

[0004] In order to solve the above technical problems, the present invention specifically provides the following technical solutions: The invention discloses a squid preservative, comprising: modified sugar, organic salt, inorganic salt and solvent; the mass ratio of the organic salt to the modified sugar is 1:0.3-2; the modified sugar is a trehalose graft, and the trehalose graft is prepared from trehalose, succinic anhydride, 2-butoxyethanol and 4-methyl-1-decanol. The trehalose graft has good freezing stability, can play a good protective role on the squid during the frozen storage process, prevent protein denaturation, maintain the moisture of the squid, and thus achieve the preservation effect.

[0005] Preferably, the organic salt is sodium lactate.

[0006] Preferably, the inorganic salt is at least one of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the mass ratio of the organic salt to the inorganic salt is 1:0.01-1.15.

[0007] Preferably, the solvent is water, and the mass ratio of the organic salt to the solvent is 1:15-30.

[0008] The invention discloses a method for preserving squid, comprising: S1: adding modified sugar, organic salt, inorganic salt and solvent into a solvent and mixing to obtain a preservative; the mass ratio of the organic salt to the modified sugar is 1:0.3-2; the modified sugar is a trehalose graft; S2: Wash the squid, cut the carcass into slices, soak it in a preservative, and after soaking, take out the squid, drain and store it.

[0009] Preferably, the organic salt in S1 is sodium lactate.

[0010] Preferably, the inorganic salt in S1 is at least one of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the mass ratio of the organic salt to the inorganic salt is 1:0.01-1.15.

[0011] Preferably, the solvent in S1 is water, and the mass ratio of the organic salt to the solvent is 1:15-30.

[0012] Preferably, the soaking time in S2 is 20-60 min.

[0013] Preferably, the storage temperature in S2 is -30-0°C.

[0014] The invention discloses a method for preserving squid, comprising: S1: adding modified sugar, organic salt, inorganic salt and solvent into a solvent and mixing to obtain a preservative; S2: Wash the squid, cut the carcass into slices, soak it in a preservative for 20-60 minutes, take out the squid after soaking, drain it, and store it at -30-0℃.

[0015] Preferably, the modified sugar in S1 is trehalose grafted product, and the mass ratio of the organic salt to the modified sugar is 1:0.3-2.

[0016] Preferably, the organic salt in S1 is sodium lactate.

[0017] Preferably, the inorganic salt in S1 is at least one of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the mass ratio of the organic salt to the inorganic salt is 1:0.01-1.15.

[0018] More preferably, the mass ratio of sodium lactate to sodium tripolyphosphate is 1:0.2-0.05.

[0019] More preferably, the mass ratio of sodium lactate to sodium pyrophosphate is 1:0.01-0.035.

[0020] More preferably, the mass ratio of sodium lactate to sodium hexametaphosphate is 1:0.01-0.03.

[0021] Preferably, the solvent in S1 is water, and the mass ratio of the organic salt to the solvent is 1:15-30.

[0022] The present invention discloses a method for preparing a trehalose grafted material, which specifically comprises: Dissolve trehalose to obtain a solution. Under nitrogen conditions, add succinic anhydride solution and triethylamine solution to the solution, react at 70-90°C for 10-15h, and then distill, separate and dry to obtain an intermediate. Add the intermediate, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 4-dimethylaminopyridine to water, react at -5-4°C for 40-60min to obtain an activation solution. Add 2-butoxyethanol and 4-methyl-1-decanol to water and dissolve to obtain a polymer solution. Then add the polymer solution to the activation solution and react at 20-30°C for 40-60h. After the reaction is completed, separate by dialysis and dry to obtain a trehalose graft.

[0023] Preferably, the solvent used to dissolve trehalose is N,N-dimethylformamide, and the ratio of trehalose to N,N-dimethylformamide is 1 g:40-60 ml.

[0024] Preferably, the succinic anhydride solution consists of succinic anhydride and N,N-dimethylformamide, and the usage ratio of succinic anhydride to N,N-dimethylformamide is 1 g: 15-25 ml.

[0025] Preferably, the mass ratio of the amount of the dissolving solution to the amount of the succinic anhydride solution used is 1:0.1-0.2.

[0026] Preferably, the triethylamine solution consists of triethylamine and N,N-dimethylformamide, and the usage ratio of triethylamine to N,N-dimethylformamide is 1g:15-25ml.

[0027] Preferably, the mass ratio of the amount of the dissolving solution to the amount of the triethylamine solution used is 1:0.1-0.2.

[0028] Preferably, the mass ratio of the intermediate to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 1:0.5-0.6.

[0029] Preferably, the mass ratio of the intermediate to 4-dimethylaminopyridine is 1:0.01-0.05.

[0030] Preferably, the ratio of the intermediate to the water in the activation solution is 1 g: 10-20 ml.

[0031] Preferably, the mass ratio of 2-butoxyethanol to 4-methyl-1-decanol is 1:0.8-1.2.

[0032] Preferably, the usage ratio of 2-butoxyethanol to water in the polymer solution is 1 g:70-90 ml.

[0033] Preferably, the mass ratio of the activation solution to the polymer solution is 1:6-7.

[0034] Preferably, in the preparation of the preservative of the present invention, hydroxytyrosol can be used in addition to the trehalose graft. The trehalose graft and hydroxytyrosol are used in synergistic manner to further effectively prevent the freezing denaturation and water loss of squid protein, delay the corruption and quality damage of squid, and thus improve the preservative effect.

[0035] More preferably, the mass ratio of sodium lactate to hydroxytyrosol is 1:0.2-1.2.

[0036] Compared with the prior art, the present invention has the following beneficial effects: The invention provides a squid preservation method. First, modified sugar, organic salt, inorganic salt and solvent are added to a solvent and mixed to obtain a preservative; then the squid is cleaned, the carcass part is cut into slices, and the slices are placed in the preservative for soaking, and after the soaking, the squid is taken out, drained and stored at low temperature. The squid preservation method of the invention is simple and easy to implement, does not require complex equipment, and the squid treated by the method of the invention contains a high salt-soluble protein and a high water holding rate of the squid, which can effectively maintain the original quality of the squid and extend the shelf life of the squid. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0038] Figure 1 This is a graph showing the results of the determination of salt-soluble protein content; Figure 2 This is the result of water holding rate measurement. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The following first describes the concepts involved in the present application in conjunction with the accompanying drawings. It should be noted that the following description of each concept is only to make the content of the present application easier to understand, and does not limit the scope of protection of the present application; at the same time, the embodiments and features in the embodiments of the present application can be combined with each other in the absence of conflict. The present application will be described in detail with reference to the accompanying drawings and in conjunction with the embodiments.

[0041] The abbreviations used in the specification and claims have the following meanings: Embodiment 1: Preparation of trehalose grafted compound: Add trehalose to N,N-dimethylformamide to obtain a dissolving solution, then add succinic anhydride solution and triethylamine solution to the dissolving solution under nitrogen conditions, and react at 80°C for 12 hours. After the reaction is completed, distillation is performed, and then acetone and ether are added, and the precipitate is separated and dried to obtain an intermediate. The intermediate, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 4-dimethylaminopyridine are added to water and reacted at 0°C for 45 minutes to obtain an activated solution. 2-Butoxyethanol and 4-methyl-1-decanol are added to water and dissolved to obtain a polymer solution. Then the polymer solution is added to the activated solution and reacted at 25°C for 48 hours. After the reaction is completed, it is dialyzed, separated and dried to obtain a trehalose grafted compound. The dosage ratio of trehalose to N,N-dimethylformamide is 1g:46ml, the succinic anhydride solution is composed of succinic anhydride and N,N-dimethylformamide, the dosage ratio of succinic anhydride to N,N-dimethylformamide is 1g:20ml, the mass ratio of the dissolved liquid to the succinic anhydride solution is 1:0.13, the triethylamine solution is composed of triethylamine and N,N-dimethylformamide, the dosage ratio of triethylamine to N,N-dimethylformamide is 1g:20ml, the mass ratio of the dissolved liquid to the triethylamine solution is 1:0.1 4. The mass ratio of the intermediate to 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 1:0.53, the mass ratio of the intermediate to 4-dimethylaminopyridine is 1:0.03, the mass ratio of the intermediate to water in the activation solution is 1g:20ml, the mass ratio of 2-butoxyethanol and 4-methyl-1-decanol is 1:1, the mass ratio of 2-butoxyethanol to water in the polymer solution is 1g:80ml, and the mass ratio of the activation solution to the polymer solution is 1:6.75.

[0042] The acute oral toxicity test of trehalose graft was carried out according to the limit method 4.3.2 of GB15193.3-2014 "National Food Safety Standard Acute Oral Toxicity Test". Trehalose graft was added to water to make a sample solution with a concentration of 500 mg / mL. The mice were pre-fed for 3 days, fasted for 5 hours before the experiment, and then gavaged with trehalose graft at a dose of 10000 mg / (kg bw), that is, the volume of the gavage sample solution was 20 mL / (kg bw). The symptoms of poisoning and behavioral changes of the mice were observed every day. No abnormal symptoms or death were observed within 14 days, and the body weight increased steadily. After the end of the experiment, no abnormalities were found in the gross anatomical examination of the mice. The median lethal dose of trehalose graft to KM mice is greater than 10000 mg / (kg bw), so trehalose graft is practically non-toxic.

[0043] Preparation of preservative: trehalose graft, sodium lactate, sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate are added into water and mixed to obtain preservative, wherein the mass ratio of sodium lactate to trehalose graft is 1:0.8, the mass ratio of sodium lactate to sodium tripolyphosphate is 1:0.03, the mass ratio of sodium lactate to sodium pyrophosphate is 1:0.02, the mass ratio of sodium lactate to sodium hexametaphosphate is 1:0.015, and the mass ratio of sodium lactate to water is 1:17.9.

[0044] Squid preservation treatment: Wash the squid, cut the carcass into slices, and then soak it in a preservative for 30 minutes. After soaking, take out the squid, drain it, and store it at -20℃.

[0045] Embodiment 2: The preparation of trehalose grafted material was the same as in Example 1.

[0046] Preparation of preservative: The preparation of the preservative in this embodiment is different from that in Example 1, except that the mass ratio of the amount of sodium lactate to the amount of the trehalose graft is 1:1.3, and the other conditions and parameters are the same as in Example 1.

[0047] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 1 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 1.

[0048] Embodiment 3: The preparation of trehalose grafted material was the same as in Example 1.

[0049] Preparation of preservative: The preparation of the preservative in this embodiment is different from that in Example 1, in that the mass ratio of the amount of sodium lactate to the amount of the trehalose graft is 1:0.5, and the other conditions and parameters are the same as in Example 1.

[0050] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 1 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 1.

[0051] Embodiment 4: The preparation of trehalose grafted material was the same as in Example 1.

[0052] Preparation of preservative: trehalose graft, hydroxytyrosol, sodium lactate, sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate are added into water and mixed to obtain preservative, wherein the mass ratio of sodium lactate to trehalose graft is 1:0.8, the mass ratio of sodium lactate to hydroxytyrosol is 1:0.6, the mass ratio of sodium lactate to sodium tripolyphosphate is 1:0.03, the mass ratio of sodium lactate to sodium pyrophosphate is 1:0.02, the mass ratio of sodium lactate to sodium hexametaphosphate is 1:0.015, and the mass ratio of sodium lactate to water is 1:17.9.

[0053] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 1 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 1.

[0054] Embodiment 5: The preparation of trehalose grafted material was the same as in Example 1.

[0055] Preparation of preservative: The preparation of the preservative in this embodiment is different from that in Example 4, except that the mass ratio of the amount of sodium lactate to hydroxytyrosol used is 1:1, and the other conditions and parameters are the same as in Example 4.

[0056] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 4 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 4.

[0057] Embodiment 6: The preparation of trehalose grafted material was the same as in Example 1.

[0058] Preparation of preservative: The preparation of the preservative in this embodiment is different from that in Example 4, except that the mass ratio of the amount of sodium lactate to hydroxytyrosol used is 1:0.3, and the other conditions and parameters are the same as those in Example 4.

[0059] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 4 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 4.

[0060] Comparative Example 1: The preparation of trehalose grafted material was the same as in Example 1.

[0061] Preparation of preservative: The preparation of the preservative in this embodiment is different from that in Example 1, except that the mass ratio of the amount of sodium lactate to the amount of the trehalose graft is 1:0.05, and the other conditions and parameters are the same as in Example 1.

[0062] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 1 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 1.

[0063] Comparative Example 2: The preparation of trehalose grafted material was the same as in Example 1.

[0064] Preparation of preservative: The preparation of the preservative in this example is different from that in Example 4 in that no trehalose graft is used. Other conditions and parameters are the same as those in Example 4.

[0065] Squid preservation treatment: The squid preservation treatment in this embodiment is different from that in Example 4 in that the preservative is the preservative prepared in this embodiment, and other conditions and parameters are the same as in Example 4.

[0066] Experimental Example 1: The salt-soluble protein content was determined by storing the squids of Examples 1-6 and Comparative Examples 1-2 at -20°C for 480 hours after preservation, then mincing the squids, adding buffer, homogenizing and extracting at 4°C for 2 hours, and then separating and collecting the supernatant to obtain the salt-soluble protein solution. The protein content was determined by the Coomassie Brilliant Blue method. The mass ratio of the squid to the buffer was 1:2.5, the buffer was a potassium chloride solution, the potassium chloride solution was composed of potassium chloride and water, and the amount ratio of potassium chloride to water was 1g:22.35ml.

[0067] The results are as follows Figure 1As shown, the squid treated with fresh-keeping in Example 1 has a lower salt-soluble protein content than that in Example 2 after low-temperature storage, indicating that the increase in the amount of trehalose grafts used within a certain range can improve the effect of the prepared preservative, effectively prevent protein freezing denaturation, and increase the salt-soluble protein content; compared with Example 3, Example 1 shows that the reduction in the amount of trehalose grafts used within a certain range will reduce the effect of the preservative, thereby reducing the salt-soluble protein content; compared with Example 4, Example 1 shows that on the basis of using trehalose grafts, hydroxytyrosol is used, and the two are used in synergistic use to prepare the preservative, which can further increase the salt-soluble protein content; compared with Example 5, Example 4 shows The results show that increasing the usage of hydroxytyrosol within a certain range can improve the effect of the preservative, thereby increasing the salt-soluble protein content; compared with Example 6, Example 4 shows that reducing the usage of hydroxytyrosol within a certain range can reduce the effect of the preservative, thereby reducing the salt-soluble protein content; compared with Comparative Example 1, Example 1 shows that the usage of the trehalose graft needs to be in a suitable range, and too low usage has no obvious effect on improving the effect of the preservative and increasing the salt-soluble protein content; compared with Comparative Example 2, Example 4 shows that hydroxytyrosol needs to be used together with the trehalose graft, and using hydroxytyrosol alone has no obvious effect on improving the effect of the preservative and increasing the salt-soluble protein content.

[0068] Experimental Example 2: Determination of water holding rate: The squids of Example 1-6 and Comparative Example 1-2 that have been preserved are stored at -20°C for 480 hours, and then the water holding rate is calculated by the pressure weight method, with a pressure of 35 kg for 5 minutes, and the weight is weighed after the pressure is completed. Water holding rate = mass of squid after pressure / mass of squid before pressure × 100%.

[0069] The water holding rate reflects the water holding capacity of the squid, which has a direct impact on the edible qualities of the squid, such as color, juiciness, and tenderness. The water holding rate of the squids treated with the preservation treatment in Example 1-6 and Comparative Example 1-2 was measured after low-temperature storage. Figure 2As shown, compared with Example 2, Example 1 shows that the increase in the amount of trehalose grafted material within a certain range can improve the effect of the prepared preservative and increase the water holding rate; compared with Example 3, Example 1 shows that the reduction in the amount of trehalose grafted material within a certain range will reduce the effect of the preservative, thereby reducing the water holding rate; compared with Example 4, Example 1 shows that on the basis of using trehalose grafted material, hydroxytyrosol is used, and the two are used in synergistic use to prepare the preservative, which can further improve the water holding rate; compared with Example 5, Example 4 shows that the increase in the amount of hydroxytyrosol within a certain range can further improve the water holding rate. The effect of the preservative can be improved, thereby improving the water holding rate; compared with Example 6, Example 4 shows that the reduction of the use amount of hydroxytyrosol within a certain range will reduce the effect of the preservative, thereby reducing the water holding rate; compared with Comparative Example 1, Example 1 shows that the use amount of the trehalose graft needs to be in an appropriate range, and too low an amount has no obvious effect on improving the effect of the preservative and improving the water holding rate; compared with Comparative Example 2, Example 4 shows that hydroxytyrosol needs to be used together with the trehalose graft, and the use of hydroxytyrosol alone has no obvious effect on improving the effect of the preservative and improving the water holding rate.

[0070] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any form. Any technical personnel in this field may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0071] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A squid preservative, comprising: Modified sugar and organic salt; the mass ratio of the organic salt to the modified sugar is 1:0.3-2; the organic salt is sodium lactate; The modified sugar is a trehalose graft, which is prepared from trehalose, succinic anhydride, 2-butoxyethanol and 4-methyl-1-decanol.

2. A squid preservative according to claim 1, characterized in that: The squid preservative further comprises an inorganic salt and a solvent.

3. A squid preservative according to claim 2, characterized in that: The inorganic salt is at least one of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the mass ratio of the organic salt to the inorganic salt is 1:0.01-1.

15.

4. The squid preservative according to claim 2, characterized in that: The solvent is water, and the mass ratio of the organic salt to the solvent is 1:15-30.

5. A method for preserving squid, comprising: S1: adding modified sugar, organic salt, inorganic salt and solvent into a solvent and mixing to obtain a preservative; the mass ratio of the organic salt to the modified sugar is 1:0.3-2; the modified sugar is a trehalose graft; S2: Wash the squid, cut the carcass into slices, soak it in a preservative, and after soaking, take out the squid, drain and store it.

6. The method for preserving squid according to claim 5, characterized in that: The organic salt in S1 is sodium lactate.

7. The method for preserving squid according to claim 5, characterized in that: The inorganic salt in S1 is at least one of sodium tripolyphosphate, sodium pyrophosphate and sodium hexametaphosphate, and the mass ratio of the organic salt to the inorganic salt is 1:0.01-1.

15.

8. The method for preserving squid according to claim 5, characterized in that: The solvent in S1 is water, and the mass ratio of the organic salt to the solvent is 1:15-30.

9. The method for preserving squid according to claim 5, characterized in that: The soaking time in S2 is 20-60 minutes.

10. The method for preserving squid according to claim 5, characterized in that: The storage temperature in S2 is -30-0°C.

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