Antimicrobial and Antioxidant Activity of Derivatives of in-vitro Digestion and Fermentation of Chitin Extracted from Field Cricket, House Cricket, and Black Soldier Fly Cocoons

Increase in microbial resistance has prompted evaluation of bioactive biopolymers such as chitin. This research assessed the antimicrobial and antioxidant activity of derivatives of in vitro digestion and fermentation of chitin obtained from field cricket, house cricket and black soldier fly. Chitin was chemically extracted and then in-vitro digested followed by fermentation using ABY 10 and ABT 5 probiotic cultures. Derivatives of in-vitro digestion and fermentation process were then tested for antioxidant and antimicrobial properties. The highest antioxidant activity in chitin samples fermented using ABY 10 was observed in derivatives of Gryllus bimaculatus, Acheta domesticus and Hermetia illucens chitin digested in vitro and fermented for 48 h at a concentration of 5mg/mL (61.11%, 63.88% and 61.63%). Similarly, among chitin samples fermented using ABT 5 starter culture, derivatives of H. illucens and A. domesticus chitin digested in vitro and fermented for 48 h at a concentration of 5 mg/mL exhibited the highest antioxidant activity (63.37% and 61.57%). Derivatives obtained after in vitro digestion and fermentation of the chitin samples exhibited significantly different antimicrobial activity against Escherichia coli, Vibrio cholerae, Bacteroides fragilis, Enterobacter agglomerans, Shigella dysenteriae, Staphylococcus aureus and Bacillus cereus. The antimicrobial activity of the derivatives increased with increase in fermentation time and sample concentration, with the highest activity being observed after 48 h of fermentation and at a concentration of 10 mg/mL. In conclusion, the study findings suggest that the development of chitin-based food products or the consumption of whole insects would potentially promote gut health.