Extraction, physicochemical characterization, and morphological properties of chitin and chitosan from cuticles of edible insects

Abstract

As an alternative, cuticles from edible insects was proposed as an unconventional but viable source of chitin and chitosan. The chitin present in the mealworm's (Tenebrio molitor) cuticles was obtained biotechnologically in one step of enzymatic deproteinization and after deacetylated. Differences in the physicochemical characteristics and the properties of the cuticles, chitin, and chitosan were investigated in this study. Commercial chitosan was used as a reference sample to validate the methods used. The enzymatic deproteinization used to obtain chitin showed an efficiency of 85%. The global yield of the process (cuticle-to-chitosan) was 31.9%. The characterization results of these polymers using DSC, FT-IR, XRD, TGA, and SEM techniques demonstrate consistency with the degree of deacetylation of the obtained chitosan, allowing the differentiation between chitin and chitosan. This study suggests that the wastes of edible insect breeding should be collected and evaluated as an alternative of chitin/chitosan source.

Keywords: Biopolymer; Enzymatic deproteinization; Mealworm’s cuticles; Tenebrio moloitor.