Extraction and characterization of phisicochemical, morphological, and structural properties of chitin and chitosan from Brachystola magna (Girard)

Abstract

Chitin was isolated from the insect Brachystola magna using an acid-alkali treatment (1 M of HCl and NaOH) at high temperature (97 °C); it was then deacetylated to chitosan (NaOH 40%/110 °C/5.5 h). The dry weight yields of chitin and chitosan were 10.4 and 8.1% respectively. Chitin and chitosan were characterized by infrared spectroscopy with Fourier transform, X-ray diffraction, scanning electron microscopy, potentiometric titration and high-performance size-exclusion chromatography; they were compared with commercial chitin and chitosan. The results showed that the obtained chitin and chitosan had chemical structures comparable to commercial polymers, with similar physicochemical properties; the obtained chitosan had a deacetylation degree of 87% and high molecular weight (25.8 kDa). Brachystola magna Girard could be considered as a potential source for obtaining chitin and chitosan in significant quantities and at low cost.