Research In The Impacting Factors Of Preservative And Shelling Pretreatment On Penaeus Vannamei

Penaeus vannamei was deeply loved by people because of delicious meat and high nutritionalvalue. but the phenol oxidase that leaded to melanosis in process of storage exist in sales Parts ofit,such as blood, head, chest, joints, the tail fan and so on. The sensory quality and commercial valueof products was affected seriously.Therefore, the preservation method of shrimp has an importantsignificance to fishery production and sales.At the same time, The processing ability of shrimp in chinais insufficient seriously, shelling technology is one of the limiting factor.At present, Hand shelling is themain method in china, but this methed is not only low efficiency, but also poor quality.Therefore,research of shelling technology with machine has become a technical problem to be solved.The complex biological preservative were get from research of Storage characteristic on penaeusvannamei. The effect of preservation and preventing the black was obviously. The change ruleof quality of penaeus vannamei processed by complex biological preservative in process of storage wasanalyzed. The dynamics model of quality changes and shelf-life of penaeus vannamei in storage wasestablished. At the same time, in order to promote large-scale processing of shrimp in china, differentshelling pretreatments on penaeus vannamei were studied. It provided a good theoretical basis andtechnical support to mechanical shelling of shrimp.1Study on the preservation effect of complex biological preservative on penaeus vannameiDifferent proportions of nano-TiO2/chitosan preservative,propolis extract,lysozyme,lactoferrin and teapolyphenol were used to treat penaeus vannamei and the storage at4±1℃. Factors of orthogonal testwere determined by index determination, such as nanometer nano-TiO2/chitosan, lysozyme and beeglue alcohol extraction liquid. The best proportion of complex preservative agent determined by theL9(3)4orthogonal experiment was:0.05%Nano-TiO2/1.5%chitosan composite,0.065%Lysozyme,0.7%alcohol extraction liquid of propolis. The shelf-life of Penaeus vannamei could prolong1.8timestreated by complex biological preservative at4±1℃.2Preservation effect of complex biological preservative on penaeus vannamei Penaeusvannamei were processed by composite biological preservative stored at different temperature.Variancetest results were analyzed by pH, sensory evaluation, total plate count, TVB-N value, Ca2+-ATPasevalue and TBA value. The best way of preservation was selected. Results showed that the compositebiological preservative combined with ice temperature storage was much better.It could prolong theshelf-life of penaeus vannamei to21days. 3Establish shelf-life prediction model of penaeus vannamei were processed by compositebiological preservative Penaeus vannamei were processed by composite biological preservativestored at10℃、4℃、0℃、ice temperature、-5℃.Select the highest correlation index with decay afterindex determination and analysis of variance. Establish shelf-life prediction model and do verifiedexperiment. Results showed that the highest pearson correlation coefficient with quality was value ofTVB-N, The dynamic model of the TVB-N value was lnA=lnA0+6.73*106*exp(9357.3/T)*t, Theshelf-life prediction model was t=(lnA-nA0)/[6.73*106*exp(9357.3/T)].4Effect of ice-salt pretreatment on shelling of penaeus vannamei Penaeus vannamei werepretreated with mixtures of different mass fraction of ice and salt for different periods of time. Withshelling time, total volatile basic nitrogen, activity of Ca2+-ATPase, hardness, elasticity of the meat,tension between shell and muscle, temperature variation as measurement index, combined with sensoryevaluation optimum pretreatment conditions for shelling of penaeus vannamei was confirmed as0.5hour of pretreatment with4%of salt and ice mixture.5Effect of low-temperature brine pretreatment on shelling of penaeus vannamei Penaeusvannamei were pretreated with different concentrations of low-temperature brine for different periods oftime. With shelling time, total volatile basic nitrogen, activity of Ca2+-ATPase, hardness, elasticity of themeat, tension between shell and muscle, temperature variation as measurement index, combined withsensory evaluation and cost optimum pretreatment conditions for shelling of penaeus vannamei wasconfirmed as1hour of pretreatment with4°Bé low-temperature brine.6The study of influence on shelling of penaeus vannamei thawed by different methodsDifferent thawing methods of brine thaw, hydrostatic thaw, microwave thawing were used to treatpenaeus vannamei. The concentration of brine, the ratio of material to water and water temperature weredetermined as response surface experiment factors of thawing by the index combining with thesenses,such as shelling time,tension between meat and shell,value of salt soluble protein, thawing time,dressing percentage and so on. The best thawing conditions determined through the response surfacetest and data analysis was that salt water was9%the water temperature was15℃, water ratio was1:10.