Insect-Derived Chitin and Chitosan: A Still Unexploited Resource for the Edible Insect Sector
Chitin and chitosan are biopolymers that are frequently found in nature and have a broad range of applications in the food, biomedical and industrial sectors, due to their high biological activity. The primary source of chitin and chitosan is shellfish, however, shortages in the supply chain, seasonality issues in their availability, as well as ecological degradation are only a few of the problems with the main chitin resources. Due to the broad spectrum of applications for which chitin can be used, the demand for chitin and its derivatives is increasing. Therefore, the market is looking for widely available, greener alternatives to the main commercial chitin sources. Insects appear as a suitable candidate to fill this gap. During insect rearing and processing, a number of side streams are generated, e.g., exuviae of larvae and pupae, dead adults, etc. which are currently mostly discarded as waste. However, these side streams could constitute a novel and long-term supply of chitin for industrial applications. Recent research has demonstrated the suitability of several edible insect species for the production of chitin and chitosan, wherein the exoskeleton of the black soldier fly and field cricket are rich in chitin, making them a good source for chitin and chitosan extraction and purification among other farmed insect candidates. Moreover, several potential uses have been identified for insect-derived chitin and chitosan. Thus, this review aims to present recent advances in the production of chitin and chitosan from edible insects, specifically on their extraction and purification, as well as on their applications for agriculture, food and nutrition, biomedicine and bioplastic production.