Abstract

In the current investigation, chitin and chitosan are extracted from Callinectes amnicola (crab) and Penaeus notialis (shrimp) shell wastes using predetermined optimization conditions. The shrimp shell produces higher chitin yield (26.08%), higher chitosan yield (16.93%) and higher degree of deacetylation (DDA) of 89.73% than the yields of chitin (19.36%), chitosan (13.29%) and the DDA from crab shell (84.20%). The Fourier Transform Infrared (FTIR) and acid-base titration methods are used to obtain % DDA of the optimized chitosan. Insignificant deviations between the DDA values from both methods are obtained. The experimental FTIR bands and standards for the refined chitosan from crab and shrimp shell wastes are in excellent agreement. The physicochemical properties of the raw precursors, extracted chitin and chitosan (raw and refined/decolorized) are equally evaluated. The extracted chitin and chitosan are characterized using analytical techniques. The implication of this study is in the current drive to produce chitin and chitosan from the underutilized shell wastes of C. amnicola and P. notialis of Nigerian sources with a high yield and a high DDA. In this study, the P. notialis shell is a better alternative source of chitin and chitosan than C. amnicola shell.

Key words: Extraction, characterization, Brunauer-Emmett-Teller (BET) surface area, Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy, transmission electron microscopy.