Selective antibacterial effect on Campylobacter of a winemaking waste extract (WWE) as a source of active phenolic compounds

Abstract

Abstract The feasibility of winemaking waste (WW) as source of active phenolic compounds against Campylobacter was evaluated using a mixture of ethanol-water (50% v/v) as extraction solvent. The winemaking waste extract (WWE) was active against all the strains tested, and most of them were inhibited at WWE concentrations between 40 and 100 mg GAE/L. However, different lactic acid bacteria (LAB) strains were practically unaffected by WWE, suggesting a selective antibacterial effect of WWE against Campylobacter . The fractioning and phenolic characterization of WWE using HPLC-MS showed that catechins and proanthocyanidins were the main compounds involved in the antibacterial effect. Among them, the structural verification using pure phenolic standards showed that epicatechin gallate and resveratrol were the most active compounds against Campylobacter. We conclude that the study of the main mechanisms involved in the antibacterial activity against Campylobacter of epicatechin gallate, resveratrol, and other related compounds presenting gallate side-chain, can contribute for future design of useful antibacterials against this pathogen.