Comparison Of Chitin Extraction From Six Common Farming Insects

Chitin is the second largest polymer in nature and is found mainly in the epidermis of crustaceans.Chitin and its derivatives have a wide range of applications in the food industry,pharmaceutical industry,environmental protection,and agriculture.China has a long history in the insect breeding industry.Today,the insect breeding industry is relatively mature.The use of these insects is mainly focused on both food and medicinal use.Due to the large scale of cultivation and the small amount of product use,large quantities of insect products are accumulated.The abundance of insect species is a green renewable resource.Judging from the status quo,the insect resource is mainly medicinal and edible.The advantage of insects as a renewable resource and combining the characteristics are an excellent raw material for large-scale industrial production.The main target of this study was artificially reared insects.Chitin was extracted from these insect resources and applied to large-scale industrial production.The more suiTab selection of insect resources for the industrial preparation of chitin has laid the foundation for the rational industrialization about insect,and at the same time,it also reduces the accumulation of insects and reduces the pollution to the environment.In this paper,the traditional acid-alkali method was used to extract the chitin of adults,larvae.The larvae and adults of Tenebrio molitor were used as model samples to investigate the optimum conditions for the extraction of chitin,and then the conditions were applied to other insects for comparison.The best conditions for larval extraction of chitin:grease extration:the ratio dichloromethane to mineral ether is 3:1?the temperature is 65?,the time is 3h;demineralization: the temperature is 60?,the concentration of sodium hydroxide solution is 6%,the time is 2 h,the ratio substrate to sodium solution is 5/70(g/ml);demineralization:the concentration hydrochloric acid solution concentration is 6M,the time is 4h,the ratio substrate to hydrochloric acid solution is 3/70(g/ml).The best conditions for adult extraction of chitin:grease extration:the ratio dichloromethane to mineral ether is 3:1,the temperature is 65 ?,the time is 4h;demineralization: the temperature is 55 ?,the concentration of sodium hydroxide solution is 6%,the time is 6 h,the ratio substrate to sodium solution is 5/70(g/ml);demineralization:the concentration hydrochloric acid solution concentration is 4M,the time is 2h,the ratio substrate to hydrochloric acid solution is 3/60(g/ml).According to the analysis of different levels of the same factor,the concentration of hydrochloric acid or sodium hydroxide used in the demineralization and deproteinizing process of the chitin content extraction process dominates the corresponding process.The highest levels of chitin content were adults of Tenebrio molitor and black-slug,followed by adults of cockroaches and barley.The lowest yield of chitin was blackwater larvae,followed by housefly larvae and mealworm larvae.When adults and larvae of tenebrio,barley worm,houseflies,and black-spotted were used to extract chitin,the adult chitin yield of these four insects was higher than that of the larvae.In addition to barley worm,the adult and larvae chitin yields of the other three insects differed significantly.