CN102524904B - Preservative and fresh-keeping method for improving refrigerating fresh-keeping effect of fresh shrimps - Google Patents

Abstract

The invention discloses a preservative and a fresh-keeping method for improving refrigerating fresh-keeping effect of fresh shrimps. The invention is characterized in that: the preservative is a plant essential oil soaking solution; the plant essential oil soaking solution is obtained by diluting a plant essential oil compound solution with water until the concentration of a mixture is 4-6ml/L; the plant essential oil compound solution consists of the following components in percentage by weight: 50 to 60 percent of tea tree essential oil, 25 to 35 percent of clove essential oil, 10 percent of eucalyptus leaf essential oil and 5 percent of torreya grandis essential oil; and the fresh-keeping method comprises the following steps of: soaking the fresh shrimps into 4-6ml/L plant essential oil soaking solution for 8 to 12 minutes, packing with fresh-keeping bags containing 0.8 to 1.2 mass percent inorganic nano antibacterial agent, and refrigerating at a low temperature. The invention has the advantages that: the quality guarantee period of the fresh shrimps treated and packed by using the method can be prolonged in the refrigerating process, good appearance and mouthfeel of the fresh shrimps are maintained, and the normal flavor of the shrimps is not affected; and the raw materials for the preservative are green and edible, so the preservative is safe and does not harm human body.

Description

A kind of antistaling agent and its fresh-keeping method for improving fresh-keeping fresh-keeping effect of fresh shrimp

technical field

The invention relates to an anti-corrosion and fresh-keeping technology for aquatic products in the field of food processing, in particular to a fresh-keeping agent and a fresh-keeping method for improving the cold-keeping and fresh-keeping effect of fresh shrimp.

Background technique

Shrimp is an important class of aquatic products, with rich and comprehensive nutrients, high protein content, a complete range of amino acids, high unsaturated fatty acids, and a variety of vitamins necessary for human metabolism, with high nutritional value , is deeply loved by consumers for its delicious taste and high nutritional value. In recent years, the cultivation and consumption of shrimps in my country have continued to increase. However, as a general characteristic of aquatic products, shrimp is extremely susceptible to bacterial infection and spoilage during fresh-keeping storage and transportation due to its high water and protein content. At the same time, there is a large amount of polyphenol oxidase (PPO) in shrimp, which can easily react with dopa substances in the body to produce melanin, resulting in blackening of shrimp, causing a sharp decline in quality, and seriously affecting its appearance quality and commodity value.

Shrimp preservation technology is to apply physical, chemical, biological and other means to treat it, so as to maintain or try to maintain its original freshness. The physical preservation of shrimp is mainly based on low-temperature storage, which is divided into freezing preservation and refrigeration preservation. The former is to quickly freeze shrimp products to about -30°C, and then freeze them at -18°C to -4°C after ice-coating treatment. Preserved at low temperature, at this temperature, the microorganisms of the shrimp body are suppressed for a long time, and various enzyme reactions and chemical reactions in the shrimp body are at a standstill, so the corruption and deterioration of the shrimp can be inhibited, but the disadvantage of using this method is that the protein of the shrimp itself Some denaturation will also occur under freezing conditions. In addition, during the freezing process, the water in the shrimp muscle is easy to volatilize and lose, which has a negative impact on the appearance and taste of the shrimp after thawing. Cold storage is to store the shrimp at 0-4°C. Under this temperature, the activity of enzymes and microorganisms in the shrimp body will be reduced, the original properties of the shrimp will be kept to the greatest extent, the freshness will be changed little, and the flavor will be improved. Keep, but refrigerated storage has a short shelf life, which is not conducive to long-distance transportation.

The chemical preservation of shrimp is mainly treated with preservatives to achieve anti-corrosion and fresh-keeping effects. The Chinese patent name is Shrimp Preservative and Its Application (Application No. 200710066793.7) discloses a shrimp preservative including a dispersant. The formula uses sulfurous acid Combine salt with a certain amount of dispersant, dissolve the preservative in water, stir evenly, and then make various shapes of fresh-keeping ice for shrimp preservation. Although this method has achieved a certain preservation effect, chemical preservation is used. , Sulfites have an impact on human health.

Biological preservation is to use natural, non-toxic, antibacterial and anti-oxidant substances, or to use fresh-keeping technologies that can improve the quality of shrimp and have no harm to the environment and human body to keep food fresh. Its biggest advantage is that it has no pollution to the environment and no adverse effects on food. Therefore, as people are more and more concerned about food safety today, the biological preservation method has a very broad prospect. Plant essential oil is a complex volatile organic substance formed by the secondary metabolism of plants. It has broad-spectrum antibacterial, antioxidative and anticancer capabilities, and can be used in food, medicine and cosmetics industries. As a natural and green biological preservative, plant essential oil can be used for antiseptic preservation of fresh foods such as fruits and vegetables, meat, eggs, etc., and its use has high safety. At present, there are no relevant research reports on the application of plant essential oils in shrimp preservation to improve the preservation effect of fresh shrimps at home and abroad.

Contents of the invention

The technical problem to be solved by the present invention is to provide a fresh-keeping agent for improving fresh-keeping effect of fresh shrimp and a method for improving fresh-keeping effect of fresh shrimp by soaking in plant essential oil fresh-keeping agent and packing in nano-material fresh-keeping bag, and using the method to process the packed shrimp Fresh shrimp can prolong the shelf life of shrimp during the cold storage process and maintain its good appearance and taste without affecting the normal flavor of shrimp. The raw material of the preservative used is green and edible, safe and harmless to the human body.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a preservative for improving the effect of cold storage and preservation of fresh shrimp, the preservative is a plant essential oil soaking solution, and the plant essential oil soaking solution is a plant essential oil compound solution plus water Diluted to a concentration of 4-6 ml/L, the composition and weight percentage of the plant essential oil compound liquid are as follows: 50-60% tea tree essential oil, 25-35% clove essential oil, 10% eucalyptus essential oil and Torreya essential oil 5%.

The composition and weight percentages of the described plant essential oil compound liquid are as follows: 55% of tea tree essential oil, 30% of clove essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil, and then the plant essential oil compound liquid is diluted with water to 5ml/ L's plant essential oil infusion. . The plant essential oil soaking liquid has the best effect on the preservation and antiseptic ability of fresh shrimp under the compound composition and concentration, and has little effect on the flavor of shrimp.

Soak the fresh shrimp in the plant essential oil soaking solution with a concentration of 4-6ml/L for 8-12 minutes, then pack it in a fresh-keeping bag containing an inorganic nano-antibacterial agent and refrigerate it at low temperature.

The plant essential oil soaking solution is obtained by adding water to the plant essential oil compound solution and diluting it to a concentration of 4-6 ml/L. The composition and weight percentage of the plant essential oil compound solution are as follows: 50-60% tea tree essential oil, clove 25-35% of essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil.

The composition and weight percentages of the described plant essential oil compound liquid are as follows: 55% of tea tree essential oil, 30% of clove essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil, and then the plant essential oil compound liquid is diluted with water to 5ml/ L's plant essential oil infusion.

Fresh shrimps were processed in the plant essential oil soaking solution for 10 minutes.

The fresh-keeping bag is blow-molded by low-density polyethylene material, and the mass concentration of the inorganic nano-antibacterial agent in the low-density polyethylene material is 0.8-1.2%, and the antibacterial effect on fresh shrimp Best for keeping fresh.

The inorganic nano antibacterial agent contains nano-silver, nano-zinc and diatomite, and the mixing ratio of the nano-silver, nano-zinc and diatomite is 3:2:5.

The mass concentration of the inorganic nano-antibacterial agent in the low-density polyethylene material is 1%.

Described fresh-keeping bag is similar to common food fresh-keeping bag thickness, and thickness is 5 wires. (1 wire = 0.01mm)

Compared with the prior art, the present invention has the advantages of: a fresh-keeping agent and a fresh-keeping method for improving fresh-keeping effect of fresh shrimps in the present invention, for the first time, plant essential oils and nano-packages are compounded and applied to fresh-keeping shrimps to improve freshness. Shrimp preservation effect. In this method, fresh shrimps are suddenly killed by ice cubes, soaked in a compound dilution of tea tree essential oil, clove essential oil, eucalyptus essential oil and Torreya essential oil, and then packed in a fresh-keeping bag containing inorganic nano-antibacterial agents and then refrigerated at low temperature. . The antistaling agent, that is, the composition ratio of the compound essential oil in the plant essential oil soaking liquid is 50-60% of tea tree essential oil, 25-35% of clove essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil.

Since plant essential oil is a natural extraction product of plants, it has good antibacterial, anti-oxidation and anti-cancer functions, and the concentration used in fresh shrimp preservation is low. Therefore, the use of this compound essential oil for treatment is harmless to the human body but beneficial. safety, and various substances in the plant essential oil compound liquid can kill or inhibit the spoilage bacteria of shrimp, and have obvious inhibitory effect on the blackening of the shrimp head, which is beneficial to the preservation of the shrimp; at the same time, the main components of the plant essential oil It is terpenes and terpenoid oxides, and has broad-spectrum antibacterial ability. Reasonable selection of essential oil types and essential oil concentrations can prevent the adverse effects of essential oils on the flavor of prawns. There is no public report on the compounding of plant essential oils, especially tea tree essential oil, eucalyptus essential oil, clove essential oil and Chinese torreya essential oil for preservation of prawns. In addition, the new food packaging fresh-keeping bags containing nano-materials are superior in fresh-keeping effect, antibacterial ability and barrier performance, which can reduce microbial spoilage and food quality deterioration. The nano-antibacterial agent contains nano-silver, nano-zinc and diatomaceous earth. Nano-silver and nano-zinc have good antibacterial ability, and diatomaceous earth is used as a filling aid to reduce the cost of antibacterial agents.

The fresh shrimp treated with the above-mentioned plant essential oil soaking solution and repackaged were stored at 4°C. After 5 days, the sensory quality score was high, and the shrimp head became less black; the pH value of shrimp meat, TVB-N (volatile basic nitrogen) value, The increase of the total number of bacterial colonies was greatly suppressed, and the freshness and quality of the shrimp were better maintained. Therefore, this method has a better antiseptic and fresh-keeping effect on fresh shrimps in low-temperature refrigeration, and provides better anti-corrosion and fresh-keeping technology in refrigerated transportation and sales of shrimps, reduces spoilage and deterioration of fresh shrimps, improves the economic value of shrimps, and avoids various chemical synthesis preservation. Potential hazards of chemicals and preservatives to humans and the environment.

Description of drawings

Figure 1 is a schematic diagram of the changes in sensory scores of prawns during storage for 5 days.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The following examples further illustrate the present invention, but the protection scope of the present invention is not limited thereto, and the protection scope is as the criterion.

1. Specific examples

The present invention is a fresh-keeping agent for improving fresh-keeping effect of fresh shrimps in cold storage. The fresh-keeping agent is plant essential oil soaking liquid, and tea tree essential oil, clove essential oil, eucalyptus leaf essential oil and Chinese Torreya essential oil are mixed according to the following weight percentages: tea tree essential oil 55%, clove essential oil 30% %, eucalyptus essential oil 10% and Torreya essential oil 5% to obtain a plant essential oil compound solution, then add a small amount of emulsifier in the plant essential oil compound solution and add water to dilute to 5ml/L to obtain a plant essential oil soaking solution. Utilize above-mentioned fresh-keeping agent to improve the fresh-keeping method of fresh-keeping effect of fresh shrimp refrigeration as follows:

Soak the fresh shrimp in the above-mentioned plant essential oil soaking solution with a concentration of 5ml/L for 10 minutes, then pack it in a fresh-keeping bag containing an inorganic nano-antibacterial agent and refrigerate it at low temperature.

In this specific example, the fresh-keeping bag is blown from low-density polyethylene material (LDPE), the mass concentration of the inorganic nano-antibacterial agent in the low-density polyethylene material is 1.0%, and the inorganic nano-antibacterial agent contains Nano-silver, nano-zinc and diatomite, wherein the mixing ratio of nano-silver, nano-zinc and diatomite is 3:2:5; the thickness of the fresh-keeping bag is 5 silk (1 silk = 0.01mm).

Except above-mentioned embodiment, the concentration of plant essential oil compound liquid in plant essential oil soaking liquid can also be 4ml/L or 6ml/L; The following weight percentages are mixed: 50% of tea tree essential oil, 35% of clove essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil or 60% of tea tree essential oil, 25% of clove essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil; It can be 8 minutes or 12 minutes; the nano-antibacterial material content in the fresh-keeping bag is 0.8% or 1.2%, which are not listed here.

2. Blank control example

Select prawns with the same size and no surface damage, and store them directly at 0°C.

3. Verification experiment

During or after 5 days of storage of the prawns in the above examples and blank control examples, the sensory evaluation, pH value of shrimp meat, TVB-N value and total number of bacterial colonies were analyzed and determined. The sensory evaluation is carried out according to the scoring standards in Table 1, and the sum of the scores is the score value of the sensory evaluation of the prawns; 5g of the sample is weighed, and 50ml of distilled water is added in a beaker, stirred evenly (mashed with a masher), and placed for 30min (constantly shake), then filter, get filtrate, measure with pH meter, directly read pH value;

The results shown in Figure 1 were obtained through measurement. As can be seen from Fig. 1, after refrigerated for 5 days, the blank control had a serious putrid smell, blackening was serious, the muscle was slightly loose, and the shell was easy to peel off; while the color and smell of the prawns processed by the method of the present invention still did not change significantly. , with a higher sensory score. It can be seen from Table 2 that the pH value of the blank control prawns at this time is 7.88, the TVB-N value is 60mg/100g, and the total number of bacteria reaches 10 ⁷ CFU/g. From the above data, it can also be judged that the shrimps at this time have been severely corrupted; However, the pH value of the prawns treated by the method of the present invention is 7.41, the TVB-N value is 23.3 mg/100g, and the total number of bacteria reaches 3.2*10 ⁴ CFU/g, which is in the first-grade freshness. The data of sensory evaluation and physical and chemical analysis all show that the method of the present invention treats and packs the quality of the prawns in the cold storage process, and the quality changes slowly, which can greatly prolong the refrigerated time of the prawns and improve the effect of cold storage. Among them, the indicators in Figure 1 and Table 2 are the average values after repeating the test three times.

Claims (7)

1. A preservative for improving fresh shrimp cold preservation effect, characterized in that: the preservative is a plant essential oil soaking solution, and the plant essential oil soaking solution is a plant essential oil compound solution diluted with water to a concentration of 4-6 ml /L, the composition and weight percentage of the plant essential oil compound liquid are as follows: 50-60% tea tree essential oil, 25-35% clove essential oil, 10% eucalyptus essential oil and 5% Torreya essential oil. 2. A kind of antistaling agent that improves the refrigerated and fresh-keeping effect of fresh shrimp according to claim 1, is characterized in that: the composition of described plant essential oil compound liquid and weight percent thereof are as follows: 55% of tea tree essential oil, 30% of clove essential oil %, 10% of eucalyptus essential oil and 5% of Chinese torreya essential oil, and then the plant essential oil compound solution is diluted with water to become a 5ml/L plant essential oil soaking solution. 3. A fresh-keeping method for improving fresh shrimp refrigeration and fresh-keeping effect, characterized in that the steps are as follows: soaking fresh shrimp in a plant essential oil soaking solution with a concentration of 4 to 6ml/L for 8 to 12 minutes, and then using an inorganic nanometer antibacterial agent It can be refrigerated at low temperature after packaging in a fresh-keeping bag. The plant essential oil soaking solution is obtained by diluting the plant essential oil compound solution with water to a concentration of 4-6 ml/L. The composition and weight percentage of the plant essential oil compound solution As follows: 50-60% of tea tree essential oil, 25-35% of clove essential oil, 10% of eucalyptus essential oil and 5% of Torreya essential oil. The mass concentration in the low-density polyethylene material is 0.8 to 1.2%, the inorganic nano-antibacterial agent contains nano-silver, nano-zinc and diatomaceous earth, the nano-silver, the nano-zinc and the The mixing ratio of diatomaceous earth mentioned above is 3:2:5. 4. A fresh-keeping method for improving fresh shrimp refrigeration and fresh-keeping effect according to claim 3, characterized in that: the composition and weight percentages of the plant essential oil compound liquid are as follows: tea tree essential oil 55%, clove essential oil 30% %, 10% of eucalyptus essential oil and 5% of Chinese torreya essential oil, and then the plant essential oil compound solution is diluted with water to become a 5ml/L plant essential oil soaking solution. 5. A fresh-keeping method for improving fresh shrimp refrigeration and fresh-keeping effect according to claim 3, characterized in that: fresh shrimps are treated in the soaking solution of plant essential oil for 10 minutes. 6. A kind of method for improving fresh-keeping effect of fresh shrimp according to claim 3, it is characterized in that: the mass concentration of described inorganic nano antibacterial agent in described low-density polyethylene material is 1%. 7. A fresh-keeping method for improving fresh-keeping effect of fresh shrimp according to any one of claims 3-6, characterized in that: the thickness of the fresh-keeping bag is 5 wires. the