Research On The Effect Of High-voltage Electrostatic Field On The Quality Of Tilapia Fillets

This paper studies the high voltage electrostatic technology of tilapia fillets, explore the best conditions for high voltage electrostatic that can extend the quality of fresh tilapia fillets,and study the traditional physical and chemical indicators, protein biochemistry, protein degradation, protease activity and muscle microstructure as well as the dynamic change rules of microbial diversity on fresh tilapia fillets in high voltage static electricity, discuss high-voltage electrostatic field impact on quality of tilapia fillets and mechanism of action, for application of high voltage electrostatic in tilapia provides the basic theory basis, and rich tilapia fillets preservation methods, promote tilapia fillets preservation technology content and competitiveness.The main research and conclusions are as follows: 1. The effect of high voltage electrostatic field combined with modified atmosphere packaging technology on the quality of Tilapia filletsThis paper studies the high voltage electrostatic field combined with modified atmosphere packaging technology effect on tilapia fillets, which were stored at temperature of controlled freezing-point, analyses and compares of 3.8 kV, 1.8 kV, 0 V high-voltage electrostatic on the influence of tilapia meat quality indexes. The results show that the high voltage electrostatic can significantly inhibit corruption and bad smell of fillets, hold fish muscle elasticity, sensory quality, can also obviously improve the drip loss, but had no significant effect on fish color; The delay effect high-voltage electrostatic to fish TVB- N value increases is ideal, to a certain extent, can delay the fat oxidation, inhibit the pH decrease in the early stage of storage; High voltage electrostatic is obvious inhibiting effect on microbial proliferation, combining modified atmosphere packaging technology, the shelf life of tilapia fillets can reach 30 d, sample without peculiar smell, than control group to extend the time for nearly 9 d. In this study, 3.8 kV high-voltage electrostatic effect is better than 1.8 kV. 2. The changes of protein degradation and biochemical characteristics during storageComparison of biochemical indicators of tilapia fillets and SDS-PAGE electrophoresis, the study found that with the extension of storage time, the two groups of samples actomyosin salt soluble,total sulfhydryl content, Ca2+-ATPase activity in general is on the decline, actomyosin surface hydrophobicity in general are on the rise, high voltage electrostatic has good inhibition effect, actomyosin salt soluble less fell by 19.4% on average every day and total sulfhydryl content on an average day less fell by 13.8%, Ca2+-ATPase activity less each day fell by 94.9% on average, surface hydrophobicity less a day on average increased by 27.2%;At the beginning of the storage, the 3.8 kV high-voltage electrostatic histone biochemistry change is bigger, to effectively suppress and biochemical characteristics change after; SDS-PAGE electrophoresis showed that under the condition of high voltage electrostatic, myosin heavy chain changes slowly, strip light density greater, low degree of muscle protein degradation in storage process, can better inhibit protein denaturation. Above all, you can know, high voltage static electricity for long-term storage of tilapia fillets have better quality. 3. The effect of high voltage electrostatic field on cathepsinThrough the analysis of cathepsin B, L, H and D activity and muscle of the microstructure change, tried to analyze high voltage electrostatic mechanism. The results show that the effect of high voltage electrostatic on cathepsin B and L active effect are significant, and little influence on activity of cathepsin H, D; Cathepsin B activity in the process of storage are on the rise, cathepsin L activity of fall after rise first, activity of cathepsin H, D increase at first and lowered later gradually changes; With the extension of cold storage time, the obvious changes in fish muscle tissue structure, characterized by muscle fibers occurred fracture and small pieces, muscle fiber area ratio significantly reduced, sarcomere clearance and the clearance area ratio increases significantly, muscle fibers by dense structure become loose. High voltage electrostatic can slightly inhibit muscle fiber fracture, but for the integrity of the muscle tissue structure effect is not obvious. 4. Tilapia fillets microbial diversity analysis in high voltage static electricityApplication of molecular biology methods under the 3.8 k V high-voltage electrostatic storage tilapia fillets is close to the microbial distribution at the end of corruption, better analyses the advantage bacterium group of tilapia fillets during storage, mainly from the following conclusions: 1, the same source but different batch samples of two groups of tilapia fillets corruption the end difference of species classification belong and diversity shows that as long as the preservation storage conditions are consistent, the difference of initial microbial to storage the advantage microbial diversity distribution at the end of almost no effect, further proves the particular corruption is a major cause of lead to deterioration of aquatic products.2, under the condition of high voltage static electricity storage tilapia fillets end corruption in the microbial flora level mainly includes carnobacterium, chitinophaga, delftia, janthinobacterium, shewanella, stenotrophomonas, among them, janthinobacterium is presumed to be Specific Spoilage Organism.