Characterization of chitin content extracted from edible insect, Coridius nepalensis (Westwood, 1837) (Hemiptera: Dinidoridae)

Chitin is the second most abundant bio-polymer after cellulose in earth. This carbohydrate polymer is one of the major components of the cell wall of some micro-organisms and exoskeleton of certain invertebrates. Recent studies show the potential application of chitin and its derivatives in chemical, medical, agricultural, food technology, pollutant treatment and textile sectors. The traditional resources of chitin for industrial processing are crustacean shells and fungal mycelia. This work attempts to extract and characterize chitin from the edible insect Coridius nepalensis . The results were compared with the commercial chitin extracted from shrimp ( Pandalus borealis ). The chitin yield of from C. nepalensis was found to be 43.97% of its dry weight. The degree of acetylation was recorded as 57.67%. FT-IR spectrum showed the extracted chitin as α - allomorph. The peaks of the chitin extracted from C. nepalensis in X-ray diffractogram are less sharp compared to commercial shrimp chitin. Thus, the degree of acetylation, FT-IR spectrum and XRD show mixture of chitin and chitosan in the extracted chitin from C. nepalensis . The crystalline index (CrI 110 ) for C. nepalensis and commercial shrimp chitin was calculated as 86.33% and 71.56% respectively. Scanning electron micrographs indicated granular surface morphology the extracted chitin of C. nepalensis, in contrast to commercial shrimp chitin, which was fibrous and porous. Thus, the present study indicates the possibility to use the adults of C. nepalensis as a new and alternative source of biomaterial.