Profile of phenolic compounds and antimicrobial potential of hydroalcoholic extracts from cashew-apple coproducts

Abstract

Phytochemicals from tropical fruits and their by-products have shown the potential to use as antimicrobial natural. This study aimed to optimize the recovery of phenolic compounds (total polyphenols and flavonoids) from cashew apple using ultrasound-assisted extraction to promote the functional attributes to its coproducts and to evaluate their antioxidant and antimicrobial potential. An experimental design applying a response surface methodology was used for the extraction process. The ethanol concentration (13.76 % to 56.21 %) and the ultrasonic bath time (21.71 to 78.28 min.) were considered as independent variables, and the polyphenols content, total flavonoids as dependent variables. The phenolic profile of optimized hydroalcoholic extracts (UPLC-QToF-MSE) and their antimicrobial potential against foodborne pathogenic bacteria was assessed. The optimized conditions for a total phenolic extract of 750 mg GAE 100 g-1 were 42.16 % ethanol and 37.34 min in an ultrasonic bath, and for total flavonoids of 479.07 mg of quercetin per 100 g-1 were 37.15 % ethanol and 25.13 min. A total of 15 compounds including quercetin and myricetin derivatives, gallic acid, and anacardic acid were identified. The extracts displayed effective action against Staphylococcus aureus and Listeria monocytogenes. The extracts were effective against foodborne pathogenic bacteria thus demonstrating their potential to be a good natural alternative to synthetic additives in the food industry.