SHRIMP SHELL WASTE AS A SOURCE OF CHITIN BIOPOLYMERS

Shrimp shell waste obtained from several industrial freezing-purchasin g plants of Guaymas, Sonora, Mex., was studied as a source of value-ad ded chitin biopolymers. In part I, the effect of different isolation c onditions on the chitin yield and chemical characteristic, was investi gated. Protein and mineral matter were removed with alkali and acid tr eatment respectively. A 2x2x3 factorial a way of a completely randomiz ed design was used in order to evaluate the effect of the process vari ables, namely, NaOH concentration (0.4 and 2%) during the deproteiniza tion and HCl concentration (3 and 5%) carried out at 40, 50 and 60 deg rees C. The best processing conditions were desproteinizaton with 2% N aOH, and demineralization with 5% HCl at 50 degrees C, in terms of fin al ash and chitin content and yield. In part II, a selection of method s of isolation of chitin and chitosan was studied in order to establis h the best conditions for scaling up a process to pilot plant level. T he processing conditions were selected from reported methods as well a s from those defined in part I. Purity of chitin samples was determine d in terms of residual protein, ash and chitin each one to produce hi, oh quality chitin (0,00% protein, 0,01% ash, 99,99% chitin) and standa rd grade chitin (0,00% protein; 0,09% ash, 99,13% chitin). Both produc ts were considered as of adequate quality and their manufacture proces s could be scaled up by futher optimization of the processing conditio ns.