Sample preparation for chitin extractionCrab shells were thoroughly washed to remove any solu-ble organics and adhering impurities including soil and protein.Cleaned samples were completely dried in an oven at 60◦C for 24 h.Dried shells were grounded using porcelain mortar and pestle. Forthe purpose of obtaining uniform size crab shell powder, groundedcrab shell was sifted through 1 mm and 0.75 mm sieves (ImpactTest Sieve, Impact Test Equipments Ltd., UK). Several fractions ofsamples were kept inside a desiccator until future use.