Abstract:
Chitin has been produced from different sea
waste sources including, molluscs (mussel and oyster shell),
crustacean (prawn and crab) and fish scale (pang and silver
scales) using deproteinization and demineralization as chemical
methods. The conditions of chemical extraction process
determine the quality of chitin. The obtained results revealed
that, about 1 and 10% HCl and NaOH were adequate concentrations
for deproteinization and demineralization process
respectively. Chitin from oyster and crab shell waste had the
highest yield of 69.65 and 60.00% while prawn, mussel shell,
pang and silver scales had the lowest yield of 40.89, 35.03,
35.07 and 31.11% respectively. Chitin solubility is controlled
by the quantity of protonated acetyl groups within the polymeric
chain of the chitin backbone, thus on the percentage
of acetylated and non-acetylated d-glucos-acetamide unit.
Good solubility results were obtained in mussel, oyster and
crab shells respectively. The chitin molecular weight characteristics
and activity are controlled by the degree of acetylation
(DA) and the distribution of acetyl group extending in
the polymer chain. DA is determined by acid-base titration
methods and molecular weight determined by Brookfield
viscometry. Both methods are found to be effective.
