Effect Of Processing Pretreatment On The Quality Of White Shrimp (Penaeus Vannamei)

In this paper,the effect of ice water pretreatment on the shelled quality of White shrimp?Penaeus vannamei?was studied.The effects of different concentrations of sodium bisulfite on the storage quality of Penaeus vannamei were studied.The apparent quality and flavor quality of frozen and cooked Penaeus vannamei was compared.The study can provide theoretical guidance for the quality maintenance of Penaeus vannamei during processing.1.Taking Penaeus vannamei as the research object,by measuring the time of shelling,the yield of shrimp,sensory index and the physical-chemical indicators?texture,colordifference,TBA value,K value and microstructure?of shrimp,combined with correlation analysis,fined that the ice water treatment for 8 h was the best process conditions.At same time,the shelling time was 1.77 min,the shrimp body elasticity was 0.51 mm,the hardness was 2124.58 g,the K value was 1.33%,and the TBA value was 0.4 mg/100 g.2.The effects of different concentrations of sodium bisulfite on the storage quality of Penaeus vannamei under two storage temperatures?4?,-20??were studied.It was found that at the initial stage of storage at 4?,A certain concentration of sodium bisulfite had a good effect on the hardness,pH and taste nucleotides of Penaeus vannamei.The color difference?a*,b*?in the late storage period was significantly different from that in the control group?p<0.05?.However,there are no significant differences in other indicators.In terms of chromatic aberration,texture,and taste nucleotides,the effect of treatment with 10 g/L of sodium hydrogen sulfite was preferred.There was no significant difference in the indexes of each group of samples treated at-20?,and it was necessary to prolong the storage period to find out the change regularity of the wihte shrimp quality.3.In order to study the difference of apparent quality and flavor quality of frozen raw and cooked Penaeus vannamei.The sensory index,physical and chemical index?water content,texture,color difference,TBA value,taste nucleotide and water state?and volatile components of frozen raw and frozen cooked prawn after being cooked were determined.Among the sensory indicators,the frozen cooked prawn group had a higher score in terms of color,while the frozen raw shrimp group had a better score in terms of taste and taste.The color difference index?L*,a*?of the frozen cooked shrimp group was significantly higher than that of the frozen raw shrimp group?L*,a*?,the texture index and taste nucleotide of the frozen raw shrimp group were significantly better than that of the frozen cooked shrimp group,and the taste activity value of taste nucleotide IMP in the frozen raw shrimp group was significantly higher than that in the other groups.There was no difference in TBA value of frozen raw and cooked shrimp,which was related to the low fat content of Penaeus vannamei.According to the results of water state,found that the ratio of bound water(P₂₁)and non-flowable water(P₂₂)in Penaeus vannamei decreased during the cooking process,while the proportion of free water(P₂₃)increased.The binding water(P₂₁)and the non-flowing water(P₂₂)in the frozen raw shrimp group were significantly higher than that in the frozen cooked shrimp group.Compared with physicochemical indexes,sensory evaluation and correlation results,the treatment of frozen raw shrimp group 1 retained better taste.The process of cook was affected the volatile components of cooked shrimp meat to some extent.Cooked shrimp meat could increase the kinds of volatile substances,but too long time would also cause losses.For the type of volatile components,frozen shrimp group 1 treated samples were better.The frozen shrimp group 2 samples were better in the total relative content of the key flavor aldehydes.The comprehensive quality and flavor indexs were better after treatment with frozen shrimp group 1.