Extraction and characterization of biopolymers from exoskeleton residues of the amazon crab Dilocarcinus pagei

Chitin is the second most abundant biopolymer worldwide and is found ina large variety of animals. Besides shrimps, other species possess significantchitin contents in their external non-edible fraction, thus allowing them tobe also economically viable sources of this macromolecule. According tomass-loss evaluation of crab residues, 78.4% of the mass is comprised ofCaCO3 and 21.6% associated to the organic phase. The chitin content foundwas 8.0% of the residue’s initial mass and after the deacetylation step, theaverage chitosan yield was 5.0% of the initial residue mass. The thermaldecomposition profiles of obtained chitin and chitosan samples werecharacteristic of biopolymers, exhibiting non-oxidative (190–360°C) andoxidative (340–670°C) events of mass loss. Vibrational spectroscopic analysisshowed that the degrees of deacetylation of the obtained chitosan sampleswere time-dependent and between 68.4 and 81.9%.