Extraction and characterization of chitin, chitosan and chitooligosaccharides from crab shell waste

An experiment was carried out to utilize the crab shell waste for the production of chitin by chemical extraction method. The obtained chitin was processed to make the more useful compound chitosan by deacetylation of chitin using strong NaOH solution at high temperature. Yield of chitin and chitosan from crab shell waste was found to be 12.2 % and 10.54 %, respectively. Chitosan was further used to produce chito-oligosaccharides (COS) by acid hydrolysis using 0.5 N H2SO4, 1N H2SO4 and 7N HCl at hourly intervals upto 6 hours and the average yield was 0.55, 0.84 and 1.93 mg/ml, respectively. Chitin and chitosan were characterized by Fourier Transform Infrared spectroscopy (FT-IR) technique which depicts different band representing various bonds present in the molecule and which were in agreement with the bands of standard chitin and chitosan. Further, COS were formed after acid hydrolysis of chitosan, which was characterized by Thin Layer Chromatography (TLC) using glucosamine as a standard.