Extraction and characterization of high purity chitosan by rapid and simple techniques from mud crabs taken from Abbottabad

Abstract

Chitosan and chitosan based materials offer diverse applications in the field of biotechnology, nanotechnology, pharmaceuticals, environmental protection and tissue engineering due to their various biological and physicochemical properties. Major sources of chitosan are shrimps, crabs and lobsters. Properties of chitosan differ with the degree of deacetylation and the molecular weight. Researchers are investigating to produce high quality chitosan in cost effective and time efficient way which was the aim of present study. The exoskeleton of mud crabs, taken from Abbottabad, was demineralized with 2mol/dm3 H2SO4 solution for 4hour and then, deproteinized with 2mol/dm3 NaOH solution for 4hour at room temperature. Yield of crude chitin was 78% which was deacetylated with 55% NaOH solution at 110oC for 4hour to obtain chitosan. After precipitation, the yield of pure chitosan form the crab shell was 39%. The degree of deacetylation of chitosan was 92% measured by potentiometric titration and the molecular weight was 1.2×106 g/mol (1200KD), determined by viscometric method. We concluded that a high quality chitosan can be produced at commercial level in Pakistan by rapid and simple techniques.