Optimize For Preservation Technology Of White Shrimp(Penaeus Vannamei)

The research object was based on the white shrimp meat,in the process of production of frozen shrimp,study the effect of ultra-high pressure on the flavor of white shrimp meat,the development of non-phosphate additive,effects of different freezing methods on protein and biochemical characteristics of shrimp,effects of different additives coating ice on the quality of shrimp was studied in this paper.1 Study on the change of flavor substances of nucleotide,free amino acids and volatile flavor substances in white shrimp meat which treatment by different pressure(control group、100、200、300、400、500 MPa). Results showed that:the highest content was AMP in flavor-enhancing nucleotides, the content of AMP was increased significantly after treated by 300 MPa(p<0.05),while continue to increase the pressure the content was reduced, inosinic acid(IMP) content by high pressure treatment showed a trend of decline in addition to the 100 MPa treatment; compared the effect of pressure on the content of umami amino acids and sweet amino acids, treated by 100 MPa and 300 MPa could incease this contend, the pressure of 100, 300 and 400 MPa could increase the contend of alanine(Ala) from 290.04mg/100 g to 451.89mg/100g、439.87mg/100 g and 462.71mg/100 g respectively. The results of electronic nose showed that the aroma of samples that treated by control group,200 and 300 MPa were similarly. There were detected 48、49、49、54、54 and 52 kinds of volatile compounds, high pressure treatment could decrease the contend of alkanes and alcohols, while it could increase the contend of olefin and aromatic compounds.2 This paper optimize the concentration of sodium chloride,sodium citrate and sodium alginate and the best water conservation formula for shrimp,on the basis of single factor test, analysis of the concentration of sodium chloride,sodium citrate and sodium alginate of shrimp thaw loss of influence by response surface methodology,that Design Exper software and use multiple regression fit the experimental data. According to the regression equation to thaw loss assessment, analysis of out the optimal combination by response surface,the results show: Sodium chloride,sodium citrate and sodium alginate shrimp thaw loss rate that is the best recipe parameters: Sodium chloride at a concentration of 2.8g/L,sodium citrate concentration of 4.0g/L,sodium alginate at a concentration of 7.5g/L,thaw loss under this condition was 6.83%,close to the predicted value.3 Investigation of the influence of shrimp protein biochemistry characteristics and microstructure by four freezing methods(monomer freeze, dipping freeze, air freeze and adding water air freeze). Study found that: shrimp actomyosin dissolution amount, total sulfhydryl content and Ca2+-ATPase activity were significantly lower with the increase of storage time. The actomyosin dissolution of fresh white shrimp was 46.28mg/g, total sulfhydryl content was 9.69mol/105 g, Ca2+-ATPase activity was 0.14 molpi/(mg pro· min). Three indexes of four samples were significantly decreased after storage 30 d,and the reduced trend of monomer frozen group was significantly lower than other three groups,the hydrophobic surface of actomyosin shrimp showed first increased sharply after a slow downward trend during storage,in the storage of 60 d reached maximum, it will slow down continue to increase the storage time. From the point of view of the muscle microstructure,the muscle fiber rupture and sarcomere gap increasing trend of monomer frozen group was the slowest in each group. The effect of monomer frozen on the biochemical characteristics of protein in southern white shrimp was minimal, could delay the degeneration rate of protein.4 In this paper,the shrimp was coated different ice coating solution(distilled water, chitosan solution, VC solution, electrolytic water and chitosan electrolytic water composite solution) to explored the impact of different additives coating ice for shrimp quality during storage by determination of thawing loss rate, color difference, texture and TBA value. Study concluded that chitosan group and VC group can effectively delay the frozen shrimp thaw loss rate increase,they could also delay the a* increase,however the changes of b* in the storage period was not significant. The effect of hardness was decrease quickly in early storage,the hardness value decreased rapidly during storage 30 d,then it changed slow down at anaphase storage. VC group and electrolytic water group could not only significantly delay the decline in shrimp hardness and elasticity, but also could effectively reduced the speed of TBA value increased.