阅读说明：本技术 一种鲈鱼涂膜保鲜方法 (Coating preservation method for weever ) 是由 方秀 刘荣城 于 2019-12-26 设计创作，主要内容包括：本发明提供一种鲈鱼涂膜保鲜方法,包括以下步骤：新鲜鲈鱼失活后用盐水冲洗并沥干,然后用大蒜切片在沥干的鲈鱼体上涂覆,将蒜汁喷淋在鱼体上,晾干；将ε-聚赖氨酸溶液与改性魔芋葡甘聚糖溶液混合,得涂膜保鲜液；将步骤1处理过的鲈鱼浸入所述涂膜保鲜液中,在料液比为1:3下浸泡15分钟后捞出,然后浸入质量百分比浓度为5%的氯化钙溶液中3～5分钟取出,清水漂洗,沥干,再包裹上一层避光聚氯乙烯纳米复合材料。本发明鲈鱼涂膜保鲜方法能在鲈鱼表面形成一层膜,起到减少细菌污染,阻止微生物生长、减弱空气氧化、减慢脂质氧化速率的作用,保鲜效果明显优于普通的低温保藏方法,经过处理的鲈鱼不影响营养价值、形态和风味,保鲜效果好。(The invention provides a coating preservation method for weever, which comprises the following steps: after the fresh weever is deactivated, washing with saline and draining, then coating the drained weever body with garlic slices, spraying garlic juice on the weever body, and airing; mixing the epsilon-polylysine solution and the modified konjac glucomannan solution to obtain a coating preservation solution; and (2) immersing the weever treated in the step (1) into the coating preservation solution, immersing for 15 minutes at a material-to-liquid ratio of 1:3, taking out, immersing into a calcium chloride solution with a mass percentage concentration of 5%, taking out for 3-5 minutes, rinsing with clear water, draining, and coating with a layer of light-resistant polyvinyl chloride nano composite material. The coating preservation method for the weever can form a film on the surface of the weever, plays the roles of reducing bacterial pollution, preventing the growth of microorganisms, weakening air oxidation and slowing down the lipid oxidation rate, has the preservation effect obviously superior to that of the common low-temperature preservation method, does not influence the nutritive value, the form and the flavor of the treated weever, and has good preservation effect.)

1. A coating preservation method for weever is characterized by comprising the following steps:

step 1, after the inactivation of the fresh weever, washing the deactivated weever with saline water and draining the weever, then coating the drained weever body with garlic slices, spraying garlic juice on the fish body, and airing the weever for later use;

step 2, dissolving konjac glucomannan in water, centrifuging to obtain a supernatant, adding an ethanol solution with the volume fraction of 95% into the supernatant, wherein the volume ratio of the supernatant to the ethanol solution is 1:2, performing ultrasonic oscillation, centrifuging to obtain a centrifugal substance, and drying to obtain purified konjac glucomannan;

step 3, dissolving sodium dihydrogen phosphate in water, adjusting the pH value to 3.8-4.0 by hydrochloric acid, adding the purified konjac glucomannan under a stirring state, uniformly stirring, filtering, drying a filter at 50-55 ℃ until the water content is 10-15%, adding urea, uniformly mixing, placing in a microwave radiation environment for 6-8 min for reaction, washing a product after the reaction by using an ethanol solution with the volume fraction of 60%, drying and crushing to obtain the modified konjac glucomannan;

step 4, mixing an epsilon-polylysine solution with the mass concentration of 0.4% and a modified konjac glucomannan solution with the mass concentration of 0.3% to obtain a coating preservation solution;

and 5, immersing the weever treated in the step 1 into the coating preservation solution, immersing for 15 minutes at a material-to-liquid ratio of 1:3, taking out, immersing into a calcium chloride solution with a mass percentage concentration of 5%, taking out for 3-5 minutes, rinsing with clear water, draining, and wrapping with a layer of light-resistant polyvinyl chloride nanocomposite.

2. The method for preserving bass in a coating manner according to claim 1, further comprising the steps of: and (3) putting the weever wrapped with the light-resistant polyvinyl chloride nano composite material into a packaging bag for vacuum packaging, and sealing after vacuumizing.

3. The method of claim 1, wherein the step 1 of inactivating is carried out by putting fresh weever into crushed ice.

4. The method for coating and preserving fresh weever according to claim 1, wherein the sodium chloride concentration of the brine in the step 1 is 25 to 30 percent.

5. The method for coating and preserving the fresh weever according to claim 1, wherein the step 5 is carried out in an environment of-1 to 4 ℃.

6. The coating preservation method for the weever as claimed in claim 1, wherein the lightproof polyvinyl chloride nano composite material is prepared by the following steps: firstly weighing 60-70 parts of polyvinyl chloride, 10-15 parts of PET, 3-7 parts of trimethylolpropane trimethacrylate, 8-12 parts of carbon nanofiber, 5-9 parts of triphenyl phosphite, 4-12 parts of polysorbate, 14-18 parts of oxidized polyethylene wax, 12-17 parts of ethyl silicone oil, 8-20 parts of cellulose diacetate, 2-5 parts of thiourea, 2-8 parts of lithium perchlorate, 3-8 parts of kaolin, 1-4 parts of an aluminate vinegar coupling agent and 5-15 parts of propyl gallate; then, the materials are mixed in a high-speed mixer at a high speed of 200 and 250 rpm; and then carrying out melt extrusion on the plastic material after high-speed mixing in a double-screw extruder, wherein the length-diameter ratio of the double-screw extruder is 30-50:1, and the extrusion interval temperature is as follows: the first interval is 160-180 ℃, the second interval is 185-195 ℃, and the third interval is 210-225 ℃; and finally, cooling and dicing the extruded high polymer material to obtain the high polymer material.

7. The method for coating and preserving the fresh weever according to claim 6, wherein the lightproof polyvinyl chloride nano composite material is prepared by the following steps: weighing 65 parts of polyvinyl chloride, 13 parts of PET, 5 parts of trimethylolpropane trimethacrylate, 10 parts of carbon nanofiber, 7 parts of triphenyl phosphite, 8 parts of polysorbate, 16 parts of oxidized polyethylene wax, 15 parts of ethyl silicone oil, 14 parts of cellulose diacetate, 4 parts of thiourea, 5 parts of lithium perchlorate, 5 parts of kaolin, 3 parts of an aluminate-acetate coupling agent and 10 parts of propyl gallate.

Technical Field

The invention belongs to the field of aquatic product preservation and technical processing, and particularly relates to a coating preservation method for weever.

Background

Weever is widely distributed in pacific, mediterranean and atlantic waters and is an important economic fish in many countries. The weever has fine and smooth meat quality and delicious taste and is deeply loved by the consumers. Common weever is selected from sea weever, river weever, rough-skinned weever, sharp weever, etc. The weever contains nutritional ingredients such as protein, fat and the like, the connective tissue in the fish meat is less than that of the poultry meat, so the weever has fine meat quality and good taste, is rich in essential amino acid required by human body, has higher EPA and DHA content, and also contains rich vitamin B, vitamin D, trace elements such as calcium, iron, phosphorus, zinc and the like. Meanwhile, the nutrient components of the fish meat are easy to deteriorate, the fish body is easy to carry more bacteria, the bacteria are easy to propagate in the fish body, the proteins and amino acids are decomposed, bad odor is generated, the flavor is changed, and the fish meat is rotten. In order to solve the problems, the conventional preservation methods comprise low-temperature preservation, ultrahigh-pressure preservation, irradiation preservation and coating preservation. Wherein the most common coating antistaling agent used in the coating fresh-keeping method is sodium alginate and chitosan. The invention patent application with the application number of 201710471261.5 discloses a coating preservative which comprises the following components in parts by weight: 4-7 parts of chitosan solution and 6-9 parts of pectin enzymolysis liquid. The preparation method comprises the steps of preparing a chitosan solution, preparing a pectin extracting solution, carrying out enzymolysis on the pectin extracting solution and preparing a coating preservative. The preservative has great influence on the nutritive value and the flavor of the weever and is not suitable for the preservation of the weever.

Disclosure of Invention

In view of the above, the invention aims to provide a coating preservation method for weever, which does not affect the nutritive value, shape and flavor of weever and has good preservation effect.

In order to achieve the purpose, the invention adopts the technical scheme that:

a coating preservation method for weever comprises the following steps:

step 1, after the inactivation of the fresh weever, washing the deactivated weever with saline water and draining the weever, then coating the drained weever body with garlic slices, spraying garlic juice on the fish body, and airing the weever for later use;

step 2, dissolving konjac glucomannan in water, centrifuging to obtain a supernatant, adding an ethanol solution with the volume fraction of 95% into the supernatant, wherein the volume ratio of the supernatant to the ethanol solution is 1:2, performing ultrasonic oscillation, centrifuging to obtain a centrifugal substance, and drying to obtain purified konjac glucomannan;

step 3, dissolving sodium dihydrogen phosphate in water, adjusting the pH value to 3.8-4.0 by hydrochloric acid, adding the purified konjac glucomannan under a stirring state, uniformly stirring, filtering, drying a filter at 50-55 ℃ until the water content is 10-15%, adding urea, uniformly mixing, placing in a microwave radiation environment for 6-8 min for reaction, washing a product after the reaction by using an ethanol solution with the volume fraction of 60%, drying and crushing to obtain the modified konjac glucomannan;

step 4, mixing an epsilon-polylysine solution with the mass concentration of 0.4% and a modified konjac glucomannan solution with the mass concentration of 0.3% to obtain a coating preservation solution;

and 5, immersing the weever treated in the step 1 into the coating preservation solution, immersing for 15 minutes at a material-to-liquid ratio of 1:3, taking out, immersing into a calcium chloride solution with a mass percentage concentration of 5%, taking out for 3-5 minutes, rinsing with clear water, draining, and wrapping with a layer of light-resistant polyvinyl chloride nanocomposite.

Further, the method also comprises the following steps: and (3) putting the weever wrapped with the light-resistant polyvinyl chloride nano composite material into a packaging bag for vacuum packaging, and sealing after vacuumizing.

Further, the inactivation in the step 1 is carried out by putting fresh weever into crushed ice.

Further, the sodium chloride concentration of the brine in the step 1 is 25-30%.

Further, the step 5 is carried out in an environment of-1 to 4 ℃.

Further, the light-resistant polyvinyl chloride nanocomposite is prepared by the following steps: firstly weighing 60-70 parts of polyvinyl chloride, 10-15 parts of PET, 3-7 parts of trimethylolpropane trimethacrylate, 8-12 parts of carbon nanofiber, 5-9 parts of triphenyl phosphite, 4-12 parts of polysorbate, 14-18 parts of oxidized polyethylene wax, 12-17 parts of ethyl silicone oil, 8-20 parts of cellulose diacetate, 2-5 parts of thiourea, 2-8 parts of lithium perchlorate, 3-8 parts of kaolin, 1-4 parts of an aluminate vinegar coupling agent and 5-15 parts of propyl gallate; then, the materials are mixed in a high-speed mixer at a high speed of 200 and 250 rpm; and then carrying out melt extrusion on the plastic material after high-speed mixing in a double-screw extruder, wherein the length-diameter ratio of the double-screw extruder is 30-50:1, and the extrusion interval temperature is as follows: the first interval is 160-180 ℃, the second interval is 185-195 ℃, and the third interval is 210-225 ℃; and finally, cooling and dicing the extruded high polymer material to obtain the high polymer material.

Further, the light-resistant polyvinyl chloride nanocomposite is prepared by the following steps: weighing 65 parts of polyvinyl chloride, 13 parts of PET, 5 parts of trimethylolpropane trimethacrylate, 10 parts of carbon nanofiber, 7 parts of triphenyl phosphite, 8 parts of polysorbate, 16 parts of oxidized polyethylene wax, 15 parts of ethyl silicone oil, 14 parts of cellulose diacetate, 4 parts of thiourea, 5 parts of lithium perchlorate, 5 parts of kaolin, 3 parts of an aluminate-acetate coupling agent and 10 parts of propyl gallate.

The key concept of the technical scheme is as follows: the coating preservative is a compound liquid of epsilon-polylysine (epsilon-PL) and modified Konjac Glucomannan (KGM), and the steps are that the fresh weever is inactivated and sterilized, the compound liquid is used for coating treatment and then is gelled by calcium chloride solution, and then the weever is fished out, rinsed, drained and coated with a layer of photophobic polyvinyl chloride nano composite material, the weever is preserved by three times of coating treatment by adopting the method, the process is simple, the operability is strong, the treatment cost is low, the fat oxidation process of the weever can be effectively inhibited, the nutritional value of the weever is not influenced, the preservation effect is good, the weever preservation period can be greatly prolonged, the weever is sprayed by adopting natural bacterium reducing substances, the bacteriostatic components in the bacterium reducing substances can effectively inhibit the growth and the propagation of bacteria to prevent the decomposition of the bacteria to protein or delay the putrefaction, thereby the shelf life of the weever is prolonged, and the secondary pollution to the weever body can be prevented by adopting a spraying mode, is favorable for ensuring the bacteria reduction effect; the three-layer coating treatment mode is adopted, and the middle layer is provided with the high-molecular composite light-resistant material, so that multiple corrosion prevention effects are achieved, the treated weever does not influence the nutritional value, the form and the flavor, and the fresh-keeping effect is good.

Detailed Description

The invention is further illustrated by the following specific examples:

the coating preservation method of the weever comprises the following steps:

step 1, pretreatment: inactivating fresh weever by using crushed ice, washing the weever by using 20 to 30 percent of saline water, draining, coating fresh garlic slices on the drained weever body, spraying garlic juice on the fish body, and airing for later use. The bacteriostatic component can effectively inhibit the growth and reproduction of bacteria to prevent the bacteria from decomposing protein or delaying putrefaction, thereby prolonging the shelf life of the weever, and simultaneously, the spraying mode can prevent the fish body from secondary pollution, which is beneficial to ensuring the bacteria-reducing effect.

Step 2, purification: dissolving konjac glucomannan in water, centrifuging to obtain supernatant, adding 95% ethanol solution into the supernatant at a volume ratio of 1:2, performing ultrasonic oscillation, centrifuging to obtain centrifugate, and drying to obtain purified konjac glucomannan. The konjac glucomannan contains impurities such as starch, free reducing sugar, amino acid and the like, and the impurities are removed through purification so as to ensure the subsequent modification effect.

Step 3, modification: dissolving sodium dihydrogen phosphate in water, adjusting the pH value to 3.8-4.0 by using hydrochloric acid, adding purified konjac glucomannan under a stirring state, uniformly stirring, filtering, drying a filter at 50-55 ℃ until the water content is 10-15%, adding urea, uniformly mixing, carrying out solid-phase esterification modification for 6-8 min under microwave radiation, washing a product after reaction by using an ethanol solution with the volume fraction of 60%, drying, and crushing to obtain the modified konjac glucomannan.

Step 4, preparing a coating preservation solution: mixing an epsilon-polylysine (epsilon-PL) solution with the mass concentration of 0.4% with a modified Konjac Glucomannan (KGM) solution with the mass concentration of 0.3% to obtain a coating preservation solution:

and step 5, coating treatment: soaking pretreated weever in the fresh-keeping liquid at the temperature of 4 +/-1 ℃ for 15 minutes at the material-liquid ratio of 1:3, taking out, then soaking in a calcium chloride solution with the mass percentage concentration of 5%, gelling for 3-5 minutes, taking out, rinsing with clear water, and draining; after draining, a layer of light-resistant polyvinyl chloride nano composite material is wrapped, so that the weever is prevented from being subjected to strong light irradiation to accelerate putrefaction and deterioration;

step 6, vacuum packaging: and (3) putting the coated weever into a packaging bag for vacuum packaging, and sealing after vacuumizing. Through vacuum packaging, be convenient for transport and store, realize the secondary simultaneously and completely cut off, avoid weever and air contact, be favorable to improving its shelf life. And then storing in a refrigerator at the temperature of-1 to 3 ℃.

The light-resistant polyvinyl chloride nano composite material is prepared by the following steps: firstly weighing 60-70 parts of polyvinyl chloride, 10-15 parts of PET, 3-7 parts of trimethylolpropane trimethacrylate, 8-12 parts of carbon nanofiber, 5-9 parts of triphenyl phosphite, 4-12 parts of polysorbate, 14-18 parts of oxidized polyethylene wax, 12-17 parts of ethyl silicone oil, 8-20 parts of cellulose diacetate, 2-5 parts of thiourea, 2-8 parts of lithium perchlorate, 3-8 parts of kaolin, 1-4 parts of an aluminate vinegar coupling agent and 5-15 parts of propyl gallate; then, the materials are mixed in a high-speed mixer at a high speed of 200 and 250 rpm; and then carrying out melt extrusion on the plastic material after high-speed mixing in a double-screw extruder, wherein the length-diameter ratio of the double-screw extruder is 30-50:1, and the extrusion interval temperature is as follows: the first interval is 160-180 ℃, the second interval is 185-195 ℃, and the third interval is 210-225 ℃; and finally, cooling and dicing the extruded high polymer material to obtain the high polymer material.

The method can also provide a coating preservative which is prepared by the following method: step 1, dissolving konjac glucomannan in water, centrifuging to obtain supernatant, adding 95% ethanol solution into the supernatant in a volume ratio of the supernatant to the ethanol solution of 1:2, performing ultrasonic oscillation, centrifuging to obtain a centrifugal substance, and drying to obtain purified konjac glucomannan;

step 2, dissolving sodium dihydrogen phosphate in water, adjusting the pH value to 3.8-4.0 by hydrochloric acid, adding the purified konjac glucomannan under a stirring state, uniformly stirring, filtering, drying a filter at 50-55 ℃ until the water content is 10-15%, adding urea, uniformly mixing, placing in a microwave radiation environment for 6-8 min for reaction, washing a product after the reaction by using an ethanol solution with the volume fraction of 60%, drying and crushing to obtain the modified konjac glucomannan;

and 3, mixing the epsilon-polylysine solution with the mass concentration of 0.4% with the modified konjac glucomannan solution with the mass concentration of 0.3% to obtain the coating preservative.

Further, the light-resistant polyvinyl chloride nanocomposite is prepared by the following steps: weighing 65 parts of polyvinyl chloride, 13 parts of PET, 5 parts of trimethylolpropane trimethacrylate, 10 parts of carbon nanofiber, 7 parts of triphenyl phosphite, 8 parts of polysorbate, 16 parts of oxidized polyethylene wax, 15 parts of ethyl silicone oil, 14 parts of cellulose diacetate, 4 parts of thiourea, 5 parts of lithium perchlorate, 5 parts of kaolin, 3 parts of an aluminate-acetate coupling agent and 10 parts of propyl gallate.

For example: weighing 65 g of polyvinyl chloride, 13 g of PET, 5g of trimethylolpropane trimethacrylate, 10 g of carbon nanofiber, 7 g of triphenyl phosphite, 8 g of polysorbate, 16 g of oxidized polyethylene wax, 15 g of ethyl silicone oil and diacetate fiber according to weight, thus obtaining the light-resistant polyvinyl chloride nanocomposite material which is safe and nontoxic, has a clean production environment and is easy to observe the quality change process of weever; the method of the invention is used for carrying out three times of film coating treatment on the weever, which can improve the bacteriostasis, prevent the water from entering and achieve the triple bacteriostasis effect.

Preferably, the concentration of the saline is 25 to 30 percent. The gelling time is 4 min.

The adopted coating preservation solution is a compound solution of epsilon-polylysine (epsilon-PL) and modified Konjac Glucomannan (KGM), and the method comprises the steps of inactivating and sterilizing fresh weever, coating the fresh weever with the compound solution, gelling the fresh weever with a calcium chloride solution, fishing out, rinsing, draining, wrapping with a layer of light-resistant polyvinyl chloride nano composite material, coating the weever for three times by adopting the method, and then vacuum-packaging the weever and storing the weever in a refrigerator.

Konjac Glucomannan (KGM) is a water-soluble polysaccharide (dietary fiber) separated from tubers of konjaku, and is an economic, efficient and natural food preservative with good water holding capacity, rheological property and antibacterial property, wherein the perennial plant is formed by combining D-glucose and D-mannose through β -1,4 glycosidic bonds.

Epsilon-polylysine (epsilon-PL), a naturally occurring homopolymer linked by isopeptide bonds between carboxyl and epsilon-amino groups, is a homomonomeric polymer containing 25-30L-lysine residues produced by fermentation of Streptomyces sp. The compound is soluble in water, edible, non-toxic to human body, thermally stable under acidic conditions, and has broad-spectrum antibacterial activity against gram-positive and gram-negative bacteria, yeast and fungi, and its antibacterial activity mechanism is electrostatic adsorption on the cell surface of microorganism, which finally causes the outer membrane to peel off due to its cationic nature, resulting in abnormal distribution of cytoplasm.

The invention has the following beneficial effects:

(1) the coating preservation method for the weever is simple in process, strong in operability and low in treatment cost, can effectively inhibit the fat oxidation process of the weever, does not influence the nutritional value of the weever, has a good preservation effect, and can greatly prolong the preservation period of the weever;

(2) the weever is sprayed by adopting the natural antibacterial substance, the antibacterial component in the antibacterial substance can effectively inhibit the growth and the reproduction of bacteria to prevent the bacteria from decomposing protein or delay the putrefaction, thereby prolonging the shelf life of the weever, and simultaneously, the spraying mode can prevent the fish body from secondary pollution, which is beneficial to ensuring the antibacterial effect;

(3) adopts a three-layer coating treatment mode and adds a layer of polymer composite light-resistant material in the middle to achieve multiple anticorrosion effects.

(4) The provided coating liquid has reasonable and scientific formula, the components are mutually cooperated and uniformly dispersed, and a uniform protective film can be formed, so that the aim of keeping fresh is fulfilled, and the shelf life of the weever is prolonged. After the coating preservative is used for coating the weever, a layer of film can be formed on the surface of the weever, so that the effects of reducing bacterial pollution, preventing the growth of microorganisms, weakening air oxidation and slowing down the lipid oxidation rate are achieved, and the preservation effect is obviously better than that of the common low-temperature preservation method.

The present invention is further illustrated by the following specific examples.