Extraction Of Chitin From Shrimp Shells Of Penaeus Vannamei And Its Application In Carboxymethylation Derivatives

Penaeus vannamei boone,also known as white limb shrimp(white-leg shrimp),shape and Chinese shrimp,Mexican shrimp similar to the average life expectancy of at least 32 months,adult shrimp can reach 24 cm,as China The highest yield of the Mainland is the most popular kind of economic shrimp,and its shrimp shell is relatively soft,soft and easy to digest meat,rich in trace elements for the cardiovascular system plays a very good protective effect.Shrimp shrimp shells as the production of waste,rich in protein,fat,chitin,astaxanthin and unsaturated fatty acids and essential amino acids,etc.,has a large development prospects,including chitin chitosan because of its special Biological activity,safety,degradation,in the biomedical,food and other industries have broad application prospects.The protease hydrolysis rate was used as the evaluation index,and the protein was used to remove the protein from the shrimp shell of Penaeus vannamei by the compound enzyme.The best choice and ratio of the protease was the best(trypsin:alkaline protease 1: 2.0).The protein hydrolysis rate of shrimp shell powder of Penaeus vannamei was the best.The optimal extraction conditions were as follows: enzyme addition amount 1.0%,citric acid concentration 0.40 mol / L,ratio of material to liquid1 was obtained by using citric acid on the basis of this compound enzyme1: 10,reaction time 4h.Finally,the surface state of chitin treated by different methods of removal of Penaeus vannamei and calcareous methods was observed by scanning electron microscopy(SEM).The effects of enzymatic and decalcified decalcification on the microscopic morphology of chitin were different.The chitin surface was clearer after decalcification,and it was confirmed that the method was simple.In order to study extracted from the head of the prawn shrimp and other scraps prepared carboxymethyl chitosan on frozen vannamei shrimp preservation process quality changes,using different concentrations(0.5%,1.0%,1.5%)of carboxymethylchitosan preservation solution Penaeus impregnation processing preservation experiment with distilled water as a control group treated shrimp.By Penaeus microbiological,physical and chemical testing,it determines the freshness of Penaeus.The results showed that the shelf life of the control group of vannamei shrimp for four days,carboxymethyl chitosan preservation solution by processing each index vannamei were significantly better than the control group,and from an economic and optimum effect the premise,at a concentration of 1.0% preservation effect of carboxymethyl chitosan preservation solution was the best.Refrigerated storage to 7days,the total number of colonies of P.vannamei 5.97 lgCFU / g,TVB-N value of24.87 mg / 100 g,is still fresh in the two indices,the shelf life of 2 times than the control group and extend the shelf life of 3-4 days.The results can provide a theoretical reference for the use of shrimp prawn heads and other scraps of chitin and its derivatives.In order to study the effect of compound preservative on the fresh-keeping effect of Penaeus vannamei,carboxymethyl chitosan,tea polyphenol and lysozyme were selected as compound raw materials for compound preservative,volatile salt nitrogen content(TVB-N),the total number of colonies(TVC value),K value and color difference were used as fresh index to study the quality characteristics of Penaeus vannamei under cold storage conditions.Three-factor three-level L9(34)were used for orthogonal test,and the variance analysis was performed to select the optimal compound group.The results showed that A> B> C,that is,carboxymethyl chitosan>tea polyphenols> lysozyme,three kinds of preservatives were obtained by orthogonal experiment.The optimum concentration of the mixture was: the concentration of carboxymethyl chitosan was 15.0g / L,the concentration of tea polyphenols was 2.0g /L,the concentration of lysozyme was 0.3g / L.