Shrimp shell waste as a source of chitin biopolymers

Shrimp shell waste obtained from several industrial freezing-purchasing plants of Guaymas, Sonora, Méx., was studied as a source of value-added chitin biopolymers. In part I, the effect of different isolation conditions on the chitin yield and chemical characteristic, was investigated. Protein and mineral matter were removed with alkali and acid treatment respectively. A 2×2×3 factorial a way of a completely randomized design was used in order to evaluate the effect of the process variables, namely. NaOH concentration (0.4 and 2%) during the deproteinization and HCI concentration (3 and 5%) carried out at 40, 50 and 60°C. The best processing conditions were desproteinizaton with 2% NaOH, and demineralization with 5% HCl at 50°C, in terms of final ash and chitin content and yield. In part II, a selection of methods of isolation of chitin and chitosan was studied in order to establish the best conditions for scaling up a process to pilot plant level. The processing conditions were selected from reported methods as well as from those defined in part I. Purity of chitin samples was determined in terms of residual protein, ash and chitin each one to produce high quality chitin (0,00% protein, 0,01% ash, 99,99% chitin) and standard grade chitin (0,00% protein, 0,09% ash, 99,13% chitin). Both products were considered as of adequate quality and their manufacture process could be scaled up by futher optimization of the processing conditions.