Changes in the Physicochemical Properties and Biological Activity of Ethanol Extract from the Insect Jeotgal

Purpose: This study aimed to investigate the physicochemical and biological activity of ethanol extracted from the insect Jeotgal based on the fermentation period and extract concentration.Methods: Tenebrio molitor and Gryllus bimaculatus were crushed and then mixed with salt. Each sample was fermented at 15℃ for 180 days, and their physicochemical properties, such as salinity, brix, pH, color value and apparent viscosity were analyzed. The total polyphenol content, 2,2-diphenyl- 1-picrylhydrazyl (DPPH) scavenging ability, 2,2′-azinobis-(3-ethylbenzothiazoline- 6-sulfonic acid (ABTS) scavenging ability and α-glucosidase inhibitory activity were measured as antioxidant activity.Results: Salinity measurement results showed no significant difference in the fermentation period, but pH and viscosity were analyzed and found to continuously decrease with the increase of the fermentation period. Based on biological activity analysis, the total polyphenol content, DPPH scavenging activity, and ABTS radical scavenging activity increased with the increase of the fermentation period, and the effect was particularly remarkable at high concentrations. The results of the α-glucosidase inhibition activity showed that the effect was small at low concentrations but sufficient at high concentrations.Conclusion: The physiological activity of ethanol extract of salted fish using insects has been confirmed, and this finding may be used as a basic data for applying insect food to fermented food.