Abstract:
Fish processing industry is a significant source for earning foreign exchange to Sri Lanka. Thus it plays a very important role in the country’s economy. When considering the cuttlefish, squid and shellfish processing, hundreds of tonnes of waste are discarded and it has become a major environmental concern due to its slow degradation. The present study was designed to isolate the biopolymer: chitosan, from selected two cephalopod species Loligo duvauceli (Indian squid - Ln) and Sepia pharaonis (Pharaoh cuttlefish-Sp) and compare them qualitatively and quantitatively with previously isolated chitosan from Penaeus monodon (Giant tiger prawn -Pm). Pre-conditioning, De-mineralization, De-proteinization, De-colouration and De-acetylation steps were followed to isolate chitosan from the prawn shell, squid pen and cuttlefish bone. After extracting chitosan samples, the percentage of yield, physico-chemical and functional properties as moisture, ash, solubility, nitrogen, WBC, FBC and DD, and FT-IR reports were analyzed to compare the extracted chitosan samples. For the three species mentioned above, prawn (Pm), cuttlefish (Sp) and squid (Ld) yield was respectively 24.27%, 28.21% and 62.6%; moisture was respectively 7.52%, 8.33% and 9.27%; ash was respectively 0.65%,0.32% and 0.04%; Nitrogen was respectively 6.16%, 82.15% and 94.08%; solubility was respectively 15.28%, 34.73% and 52.17% ; WBC was respectively 600.61%, 673.27% and 705.21% and also FBC in coconut oil was respectively 644.15%,767.84% and 853.42%. in sunflower oil was respectively 556.53%, 602.45% and 678.23, and in soybean oil was respectively 65.21%, 637.21% and 778.65%. Among the three chitosan samples, chitosan isolated from the pen of Loligo duvauceli (Indian squid) was of best quality and was better than chitosan isolated from Penaeus monodon exskeleton. Possibility of using cephalopod and prawn waste to produce good qulity chitosan is evident from the results and it could be a good solution to reduce the environmental hazards caused by fih processing waste. Low cost techniques should be adopted to isolate chitosan, from fish processing waste, which should be considrred as a valuable resource for production of chitosan having many important industrial applications.
