Green extraction and biological activity of phenolic extracts from cashew nut testa using a combination of enzyme and ultrasound-assisted treatments.

Abstract

A combination of enzymes and ultrasound treatment was employed to extract bioactive compounds from cashew nut testa, a by-product of the food industry. The total catechin, flavonoid, and phenolic content of extracts was investigated together with their biological activity. Enzyme and ultrasound-assisted extraction (E-UAE) was performed by incubation with Viscozyme L (20 mL kg-1 of testa powder, v/w) for 60 min before sonication for 40 min. Ultrasound and enzyme-assisted extraction (U-EAE) was carried out using sonication for 40 min before incubation with Viscozyme L (20 mL kg-1 of testa powder) for 60 min. Under appropriate conditions, the total phenolic, flavonoid, catechin, and epigallocatechin gallate content of the extracts from cashew nut testa obtained from a combination method (U-EAE or E-UAE) was significantly higher than that obtained using a single method (EAE or UAE). Extracts of cashew nut testa obtained from E-UAE displayed significantly higher antioxidant and α-amylase inhibitory activity than those from the U-EAE. The E-UAE extract at a concentration of 100 μg mL-1 had a greater impact on the cell viability of MCF-7 after treatment (22% cell viability) than did the doxorubicin (DOX) at 4 μg mL-1 (39% cell viability), and the E-UAE extract at 100 μg mL-1 was considered to be safe for healthy cells because the viability of the bovine aerotic endothelial cells treated with this extract was 91%, which was similar to the DOX treatment. The extract of cashew nut testa obtained from E-UAE is valuable and promising for the development of anti-inflammatory therapeutic drugs. © 2023 Society of Chemical Industry.