Functional and bioactive properties of chitosan produced from Acheta domesticus with fermentation, enzymatic and microwave-assisted extraction

Edible insects are an important source of chitin and chitosan. Different methods, including the use of proteases, fermentation and microwave treatment, have been proposed to replace the conventional chitin isolation methods. House crickets are among the most commonly used insects for food applications. Chitosan was produced from house crickets from chitinous materials that were isolated via the conventional method, a biological process that combines fermentation with Lactococcus lactis and digestion with bromelain and a microwave-assisted chemical method. All chitosans were evaluated for their purity, functional properties and bioactive properties, namely their antioxidant and antimicrobial activity. All three methods generated chitosan with a purity higher than 85% and an exceptionally high oil binding capacity with a maximum of 1078.62 g oil per g chitosan for the chitosan produced with the conventional method. Furthermore, all cricket-derived chitosans showed a significant level of antioxidant activity with an effective concentration of 5 mg mL⁻¹ or lower and antimicrobial activity against Escherichia coli, Staphylococcus aureus and Salmonella enterica ssp. Enterica Serovar Typhimurium. It was concluded that the biological chitin extraction method could lead to the generation of a chitosan material with high potential for application in different sectors.