Insect processing for chitin production

Chitin is an abundant natural biopolymer that is present in the exoskeleton of edible insects. Chitosan (a derivative of chitin) is particularly interesting due to its bioactivity, biocompatibility, biodegradability and adsorption properties. Various processes can be applied for chitin extraction from insects. The most common refers to sequential solid-liquid extraction steps from the insect biomass which aim to remove chitin impurities and other components, e.g., lipids, proteins and minerals. These extraction steps are performed with harsh acidic and alkaline solutions with a simultaneous thermal treatment. Bioprocesses, e.g. fermentation and enzymatic treatment, green solvents, e.g. deep eutectic solvents and organic acids and emerging technologies, e.g. microwaves and ultrasounds, have been suggested as more environmentally sustainable, less influencing the isolated chitin and due to the possibility of utilizing the generated fractions of each extraction step. The applicability of these processes on edible insects is promising; however, they need to be thoroughly explored prior to commercial uptake.