Preparation Of Chitosan And Its Influence On The Effect Of Chinese Shrimp

Chinese shrimp is a nutrient-rich,ideal food for human health,but because of its high moisture content and rich protein in muscle,microorganisms and corruption were easy to grow,so the research on how to extend its storage period is also a hot spot in today’s society.In this paper,shrimp shell of shrimp was used as raw material to optimize the decalcification and deproteinization process,and the optimum process conditions for the preparation of chitin were obtained through response surface design.Chitosan was prepared from homemade chitin by microwave assisted alkaline method,the effects of particle size,microwave power,solid-liquid ratio and alkali concentration on the degree of deacetylation of chitosan were investigated.Chitosan was compounded with ε-polylysine and carrageenan,the optimal ratio was obtained through the pre-experiment.,sensory evaluation,total number of colonies,pH,TVB-N,TBA,texture characteristics,k value were used as indexes,combined with SDS-PAGE gel electrophoresis and electronic nose detection technology,explored the effects of different coating treatments on storage days of Chinese shrimp.The main conclusions are as follows:1.The optimal conditions of chitin preparation were determined by single factor experiment and Box-behnken response surface design.The optimal conditions of decalcification were obtained as follows: solid-liquid ratio 1:12,reaction Time 2.5 h,citric acid concentration of 8%,ash content of 0.42%.The optimum conditions were as follows: adding 2200 U/g enzyme,reaction time 5 h,reaction temperature 50 ℃,and the protein concentration could reach 31.42% by taking the protein content as the index.2.Chitosan was prepared from homemade chitin.Through single factor experiment and orthogonal experiment,to explore a high degree of deacetylation of chitosan preparation.The results showed that when chitosan with 30 mesh particle size was used as raw material,45% lye concentration,solid-liquid ratio 1:15 and microwave power 500 W were the reaction conditions,the degree of deacetylation of chitosan reached the highest.3.During cold storage,the total number of colonies,pH value,TBA value,TVB-N content,texture properties,k value of shrimp were significantly lower than those of the blank control group.Among them,composite coating treatment group was better than single coating treatment effect,compared with the blank group can extend the shelf life of Chinese shrimp 4 d.Therefore,composite coating treatment of shrimp in China has a good application prospectsElectronic nose detection could effectively distinguish four treatment methods,and it indicates that the main volatile odors of Chinese shrimp are sulfur compounds,nitrogen oxides and hydrocarbons during storage.