Method of green and safe preservation for aquatic products at sea

Patent metadata

Field	Value
Publication number	US-11617374-B2
Application number	US-201916452508-A
Country	US
Kind code	B2
Filing date	Jun 25, 2019
Priority date	Jun 25, 2018
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A method for preserving aquatic products at sea includes the following steps: an on-board refrigeration system is used to refrigerate the antifreeze solution, and the antifreeze solution is used as a main cold source, and temperatures at centers of fish bodies drop rapidly to achieve rapid cooling and reduce activity of endogenous enzymes and inhibit proliferation of microorganisms by direct or indirect heat exchange with captured catches. The antifreeze solution contains edible alcohol, propylene glycol, glycerol, calcium chloride, sodium chloride, amino acids, Antarctic krill protein hydrolysate with average molecular weight of 50-100 KDa, surfactant and water, and the mass percentage of each component is as follows: edible alcohol 15%-30%, propylene glycol 10%-30%, glycerol 2%-15%, calcium chloride 1%-10%, sodium chloride 3%-10%, amino acid 0.1%-0.15%, Antarctic krill protein hydrolysate 0.01%-0.3%, surfactant 0.005%-0.5%, and the balance is water.

First claim

What is claimed is:

1. A method for preserving aquatic products at sea, comprising the following steps:
providing a device comprising a cold storage tank for receiving an antifreeze solution, a cooling unit for holding fish bodies from a catch, a circulation line connecting the cold storage tank to the cooling unit, and an on-board refrigeration system for circulating the antifreeze solution via the circulation line from the cold storage tank to the cooling unit;
circulating the antifreeze solution added to the cold storage tank from the cold storage tank to the cooling unit via the circulation line by an on-board refrigeration system to decrease temperatures at centers of fish bodies rapidly to achieve rapid cooling, reduce activity of endogenous enzymes, and inhibit proliferation of microorganisms by direct contact between the antifreeze solution and fish bodies by submerging fish bodies in the cooling unit in the antifreeze solution or indirect contact between the antifreeze solution and the fish bodies through circulating the antifreeze solution in a wall of the cooling unit holding the fish bodies;
wherein the antifreeze solution consists of edible alcohol, propylene glycol, glycerin, calcium chloride, sodium chloride, amino acid, Antarctic krill protein hydrolysate with an average molecular weight of 50-100 KDa, surfactant, and water; wherein the surfactant is one or mixture of phospholipid, polysorbate-20, polysorbate-60, and polysorbate-80; and wherein each component of the antifreeze solution is food grade, and the mass percentage of each component is as follows:

edible alcohol
15%-30%

propylene glycol
10%-30%

glycerol
 2%-15%

calcium chloride
 1%-10%

sodium chloride
 3%-10%

amino acid
 0.1%-0.15%

Antarctic krill protein hydrolysate
0.01%-0.3% 

surfactant
0.005%-0.5%  

water
balance.

2. The method according to claim 1 , wherein
an enzymatic hydrolysis with papain hydrolyzes Antarctic Krill to obtain an Antarctic krill crude protein hydrolysate solution, wherein the solution is sequentially passing through an ultrafiltration membrane with membrane pore molecular weight of 100 KDa to 50 KDa to obtain the protein hydrolysate with an average molecular weight of 50 KDa to 100 KDa.

3. The method according to claim 1 , wherein the amino acid is selected from the group consisting of glycine, alanine, and arginine.

4. The method according to claim 1 , wherein the propylene glycol has a mass percentage of 10%-20%, and the glycerin has a mass percentage of 2%-5%, and the calcium chloride has a mass percentage of 1%-5%.

5. The method according to claim 1 , wherein the cooling unit comprises a cooling tank or an on-board refrigeration house; wherein the device further comprises a heat exchanger; wherein both a wall of the cold storage tank and a wall of the on-board refrigeration house are provided with a coil; wherein a circulation line comprises a self-circulation line, a first circulation line, a second circulation line, or a third circulation line; wherein the self-circulation line controlled by a first valve and a first circulation pump is formed at the cold storage tank, the first circulation line controlled by the first valve and the first circulation pump is formed between the coil of the on-board refrigeration house and the cold storage tank, the second circulation line controlled by a valve and a circulation pump is formed between the cold storage tank and the heat exchanger, the third circulation line controlled by a third valve and a third circulation pump is formed between the cooling tank and the heat exchanger; and wherein the method includes the following steps:
(1) the antifreeze solution is added into the cold storage tank, the on-board refrigeration system is started, the first valve is opened to make the self-circulation line communicating, the first circulation pump is started to make the antifreeze solution flow in the cold storage tank, the coil of the cold storage tank and the on-board refrigeration system exchange heat for cooling, so that a temperature of the antifreeze solution in the cold storage tank is kept between −45° C. to −10° C., and then the self-circulation line is disconnected;
(2) the cooling tank is added with seawater, a salt content in the seawater is adjusted according to an empirical formula and a required temperature of cold seawater, the empirical formula is T=−0.0636×C, where T represents the required temperature of cold seawater, and the unit is ° C.; C represents the salt content in seawater, the unit is g/L; the second and third valves are opened and the second and third circulation pumps are started to make the second circulation line and the third circulation line communicating at the same time, so that the seawater in the cooling tank and the antifreeze solution in the cold storage tank exchange heat for cooling through the heat exchanger, so that a temperature of the seawater in the cooling tank is reduced to 0° C. to −10° C.; then the catch is transferred into the cooling tank and contact the cold seawater at 0° C. to −10° C. to cool the fish bodies quickly, making the temperatures of the centers of the fish bodies to be at −5° C. to 5° C. thus to meet a cooling requirement; and during a cooling process, the communication of the second circulation line and the communication of the third circulation line is kept to provide cooling for the catch; and
(3) after the cooling process is completed, the second circulation line and the third circulation line are disconnected, and the seawater in the cooling tank is discharged through the seawater discharging port, the first valves is opened to make the first circulation line communicating at the same time, and the first circulation pump is started to make the antifreeze solution in the cold storage tank flow into the coil in the wall of the on-board refrigeration house, so that a temperature of the on-board refrigeration house is lowered and kept at 0° C. to −10° C., and after the seawater in the cooling tank is drained, the catch is transferred to the on-board refrigeration house to maintain freshness.

6. The method according to claim 5 , wherein a filter is further arranged between the cooling tank and the heat exchanger, and wherein the third valve, the filter, and the third circulation pump are sequentially arranged in a flowing direction from the cooling tank to the heat exchanger.

7. The method according to claim 1 , wherein the cold storage tank comprises a first cold storage tank and a second cold storage tank, the cooling unit comprises a cabin, and both a wall of the first cold sto

Assignees

• Univ Zhejiang Technology

Inventors

• Ding Yuting
• Liu Shulai
• Zhou Xuxia
• Liu Jianhua
• Lv Fei
• Zhang Jianyou
• Wang Yanbo
• Zhang Zhenyu

Classifications

• A23B2/733

  Compounds of undetermined constitution obtained from animals or plants · CPC title

• A23B2/742

  Organic compounds containing oxygen · CPC title

• A23B4/20

  Organic compounds; Microorganisms; Enzymes · CPC title

• A23B4/24

  Inorganic compounds · CPC title

• A23B4/09 Primary

  with direct contact between the food and the chemical, e.g. liquid N2, at cryogenic temperature · CPC title