CN111838291A - High-pressure preservation method for tilapia - Google Patents

Abstract

The invention belongs to the technical field of food preservation, and particularly relates to a high-pressure preservation method for tilapia mossambica; bone meal is prepared by acidizing, enzymolysis and activation of fishbone, the bone meal is mixed with sodium bicarbonate to prepare a softening agent, fresh tilapia is treated and then treated under ultrahigh pressure, so that the preservation time of the tilapia is prolonged, and the total number of bacterial colonies is 2.7 multiplied by 10 when the tilapia is preserved for 30 days³CFU/g, ph 6.3, TVB-N0.142 mg/g.

Description

A kind of high pressure preservation method of tilapia

technical field

The invention belongs to the technical field of food preservation, in particular to a high-pressure fresh-keeping method for tilapia.

Background technique

Tilapia, native to Africa, is a tropical fish and is the main aquaculture product in my country. It has delicious meat, less thorns, high protein content, and is rich in 8 essential amino acids needed by the human body, of which glutamic acid and glycine are particularly high. The export of tilapia products in my country is mainly sold in the form of freezing, and freezing will destroy the tissue structure of the fish, and the meat juice will be frozen and solidified into ice crystals, which will pierce the fish cells. The mouth feels a greater impact.

At present, the commonly used preservation technologies are mainly low-temperature freezing, modified atmosphere preservation, chemical preservation, and spraying edible plastic wrap on food. Freezing at low temperatures may cause freezing damage, partially freezing the fish, affecting the quality of the fish. The long-term use of chemical preservatives poses a food safety hazard.

The patent document with the publication number of CN103168829A discloses a method for ultra-high pressure preservation of seaweed, which is to wash the fresh seaweed and package it in PA/PE plastic bags, 80% of the seaweed is seaweed, 20% is pure water, and the pressure is 350-550MPa. Perform ultra-high pressure sterilization for 3-5min, and then refrigerate at 1-5℃, it can be stored for more than 120 days. It mainly uses ultra-high pressure to sterilize the seaweed, and isolates the contact between the seaweed and the air, so as to achieve the purpose of extending the shelf life, and has a good effect on the preservation of vegetables and fruits. The way of preservation effect is not ideal.

The patent document with the publication number of CN110915850A discloses a method for simultaneously preparing fish bone meal and antioxidant by utilizing fish bones. The method is to cook the fish head and fish bones and then enzymatically hydrolyze them, and then add sugar and dry to obtain the fish bone meal. However, the method of removing fishy smell was not mentioned in the preparation process, and sugar was added. In the subsequent preservation process of bone meal, due to the presence of moisture in the air, the bone meal may become damp and dissolve the sugar in it, thereby causing decay. bad or attract mosquitoes.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a high-pressure fresh-keeping method for tilapia.

Specifically, this is achieved through the following technical solutions:

1. Slaughter the fresh tilapia, remove the internal organs, scales and gills, take the clean fish, apply a softener of 5-7% of the weight of the fish evenly on the fish, and then wash it for 2-3 hours;

2. The fish fillets are vacuum-packed, and the pressure is 260-280MPa for ultra-high pressure treatment for 3-5min with water as the pressure medium.

Further, the softener is obtained by mixing bone meal and sodium bicarbonate in a mass ratio of 5-7.5:1-2.4.

Further, described bone meal, its preparation method is:

a. Acidification: rinse the fish bones with boiling water for 15-30s, then soak them in citric acid solution with twice the mass and concentration of 10-20% for 40-70min. After washing, add water and grind to obtain bone pulp ;

b. Enzymatic hydrolysis: Protease and trypsin are mixed in a mass ratio of 2-3.6:0.8-1.4, then added to bone pulp and treated at 40-50°C for 1-2h;

c. Activation treatment: The enzymatically hydrolyzed bone pulp is activated by microwave with a power of 400-800W for 30-90 minutes, and then dried and crushed to obtain bone meal.

Further, the high-pressure preservation method can also be applied to the preservation of meat such as beef and mutton.

To sum up, the beneficial effects of the present invention are as follows: the present invention adopts the fish bones to undergo acidification, enzymolysis and activation treatment to make bone meal, and is blended with sodium bicarbonate to make a softener. High pressure treatment prolongs the storage time of tilapia. The total number of colonies was 2.7×10 ³ CFU/g, the pH value was 6.3, and the TVB-N value was 0.142 mg/g after storage for 30 days.

Among them, the treatment of fish bones to make bone meal can not only use aquatic by-products as waste, but also make bone meal rich in calcium. After mixing with calcium bicarbonate, it can act on fish meat together. The glycogen in the meat will continue to undergo a metabolic reaction, namely glycolysis. In this process, the glycogen will be decomposed into lactic acid and accumulated in the muscles, thereby affecting the taste and quality of the meat, and shortening the shelf life of the meat. Calcium ions in bone meal can activate calcium activating enzymes and promote muscle tenderness. At the same time, sodium bicarbonate and calcium carbonate can react with lactic acid to reduce the lactic acid content in muscles, thereby improving the taste and flavor of meat. Blanch the fish bones with boiling water first to remove the remaining blood and other impurities, and then soak them in citric acid solution to soften the bones and remove the fishy smell of the fish bones to avoid affecting the flavor of the tilapia. Mixed enzyme for enzymolysis treatment can dissolve calcium to the maximum extent, and then treat with microwave radiation, which can not only kill the activity of the enzyme, but also cause cracks in the fish bone meal under the action of thermal stress when the electromagnetic field is radiated to the inside of the bone meal. , the grindability of fish bone meal is improved, and the effect of auxiliary crushing is played. The smaller the particle size of the bone meal, the higher the dispersibility. Then use ultra-high pressure to treat tilapia, which only destroys the non-covalent bonds that maintain the high-level structure of biological macromolecules, but has little effect on its covalent bonds, vitamins and small molecule volatile substances. The principle is ultra-high pressure. Starch gelatinization, protein denaturation, enzyme inactivation, instant destruction of microbial cells and death, that is, the high-level structure of macromolecular substances is changed, but there is no obvious impact on small molecular substances such as food pigments, aroma components and vitamins. Complete preservation, the original color, aroma, taste and nutrients of the food are kept to the maximum extent, and the quality of the food is greatly improved. The level of safety of raw food also played a supporting role.

Detailed ways

The specific embodiments of the present invention are described in further detail below, but the present invention is not limited to these embodiments, and any improvement or substitution in the basic spirit of the present embodiment still belongs to the scope of protection of the claims of the present invention.

Example 1

1. Slaughter the fresh tilapia, remove the internal organs, scales and gills, take the clean fish, apply a softener with 6% of the weight of the fish evenly on the fish, and wash it for 2.5 hours;

2. Vacuum-pack the fish fillets, and use water as the pressure medium to carry out ultra-high pressure treatment for 4 minutes at a pressure of 270MPa.

Further, the softener is obtained by mixing bone meal and sodium bicarbonate in a mass ratio of 6:1.8.

Further, described bone meal, its preparation method is:

a. Acidification: rinse the fish bones with boiling water for 15-30 s, then soak them in a citric acid solution with twice the mass and a concentration of 15% for 55 minutes, wash with water, add water and grind to obtain bone pulp;

b. Enzymatic hydrolysis: Protease and trypsin were mixed at a mass ratio of 2.8:1.1, then added to bone pulp and treated at 45°C for 1.5h;

c. Activation treatment: The enzymatically hydrolyzed bone pulp was activated by microwave with a power of 700 W for 80 minutes, and then dried and crushed to obtain bone meal.

Example 2

1. Slaughter the fresh tilapia, remove the internal organs, scales and gills, take the clean fish, apply a softener with 7% of the weight of the fish evenly on the fish, and wash it after 2 hours;

2. The fish fillets are vacuum-packed, and the pressure is 280MPa for ultra-high pressure treatment for 3 minutes with water as the pressure medium.

Further, the softener is obtained by mixing bone meal and sodium bicarbonate in a mass ratio of 7.5:2.4.

Further, described bone meal, its preparation method is:

a. Acidification: rinse the fish bones with boiling water for 30s, then soak them in a 20% citric acid solution of twice the mass for 40min, wash with water, add water and grind to obtain bone pulp;

b. Enzymatic hydrolysis: Protease and trypsin were mixed in a mass ratio of 3.6:1.4, then added to bone pulp and treated at 50°C for 1 hour;

c. Activation treatment: The enzymatically hydrolyzed bone pulp was activated by microwave with a power of 800 W for 30 minutes, and then dried and crushed to obtain bone meal.

Example 3

1. Slaughter the fresh tilapia, remove the internal organs, scales and gills, take the clean fish, apply a softener with 5-7% of the weight of the fish evenly on the fish, and then wash it for 2 hours;

2. Vacuum-pack the fish fillets, and use water as the pressure medium to carry out ultra-high pressure treatment at a pressure of 260 MPa for 5 minutes.

Further, the softener is obtained by mixing bone meal and sodium bicarbonate in a mass ratio of 5:1.

Further, described bone meal, its preparation method is:

a. Acidification: rinse the fish bones with boiling water for 15s, then soak them in a citric acid solution with twice the mass and a concentration of 10% for 70min, wash with water, add water and grind to obtain bone pulp;

b. Enzymatic hydrolysis: Protease and trypsin were mixed in a mass ratio of 2:0.8, then added to bone pulp and treated at 40°C for 2 hours;

c. Activation treatment: The enzymatically hydrolyzed bone pulp was activated by microwave with a power of 400 W for 90 minutes, and then dried and crushed to obtain bone meal.

Screening experiments

Experiment 1-2: Under the same conditions as Example 1, the softener was replaced with bone meal and sodium bicarbonate respectively;

Experiment 3: Under the same conditions as Example 1, without adding softener, directly carry out ultra-high pressure treatment;

Experiment 4: Under the same conditions as in Example 1, the fish bones were not soaked in citric acid solution; Experiment 5: Under the same conditions as in Example 1, without enzymatic hydrolysis, the fish bones were dried and microwaved and then pulverized; 6: Under the same conditions as in Example 1, the fish bones were blanched and then dried and directly pulverized; Experiments 7-8: Under the same conditions as those in Example 1, the pressure was changed to 100MPa and 400MPa respectively during ultra-high pressure treatment ;

Experiment 9: Under the same conditions as Example 1, the amount of softener was changed to 15%;

The tilapia fillets processed in Example 1 and Experiments 7-8 were tested for the number of colonies at 1 day, 7 days, 15 days, and 30 days, respectively, and compared with the blank control group. The results are shown in Table 1;

Among them, in the blank control group, tilapia were slaughtered and sliced and stored in a refrigerated manner.

Table 1

Among them, the blank control group stopped detecting the total number of colonies after 10 days of refrigeration because the product was spoiled. In experiment 8, the total number of colonies was low at the initial stage, but the quality of the treated tilapia meat became looser and the quality decreased.

The tilapia fillets processed in Experiment 1-3 and Experiment 7-9 were detected at 1 day, 7 days, 15 days, and 30 days, respectively, and the pH value of fish meat was detected, and compared with Example 1. The results are shown in Table 2. .

Table 2

The tilapia fillets processed in Experiment 1-3 and Experiment 7-8 were tested for TVB-N at 1 day, 7 days, 15 days and 30 days respectively, and compared with Example 1, the results are as shown in Table 3 .

table 3

The element content of the bone powder prepared in experiments 4-6 was determined by atomic absorption spectrometry, and the components of the bone powder prepared in Example 1 were compared. The results are shown in Table 4.

Table 4 (mg/g)

Among them, the bone meal prepared in Experiment 4 and Experiment 6 had a strong fishy smell, which had a certain influence on the flavor of fish meat.

Claims (8)

1. A high-pressure preservation method for tilapia is characterized by comprising the following steps:

a. slaughtering fresh tilapia, removing viscera, fish scales and gills, taking clean fish meat, uniformly coating softening agent accounting for 5-7% of the weight of the fish meat on the fish meat, treating for 2-3h, and cleaning;

b. vacuum packaging the fillets, and carrying out ultrahigh pressure treatment by using water as a pressure medium to obtain the fillets.

2. The high-pressure preservation method for tilapia according to claim 1, characterized in that the softening agent is obtained by mixing fishbone with sodium bicarbonate after acidification, enzymolysis and activation.

3. The high-pressure preservation method for tilapia according to claim 2, characterized in that said acidification is to wash and scald the fishbone in boiling water for 15-30s, then soak it in citric acid solution, wash it in water, and then add water and grind it into bone slurry.

4. The high-pressure preservation method for tilapia according to claim 2, characterized in that the enzymolysis is carried out by mixing protease and trypsin according to the mass ratio of 2-3.6:0.8-1.4, adding into bone slurry, and treating at 40-50 ℃ for 1-2 h.

5. The high-pressure preservation method for tilapia according to claim 2, characterized in that the activation treatment is to activate the bone slurry after enzymolysis for 30-90min by using microwave with power of 400-800W, and then to dry and crush to obtain bone powder.

6. The high-pressure preservation method for tilapia according to claim 2, characterized in that the mass ratio of the bone meal to the sodium bicarbonate of the softening agent is 5-7.5: 1-2.4.

7. The high-pressure preservation method for tilapia according to claim 1, characterized in that the ultrahigh pressure treatment is carried out under the pressure conditions of 260-280MPa for 3-5 min.

8. The application of the high-pressure preservation method is characterized in that the method can be applied to the preservation of tilapia and the preservation treatment of beef and mutton.