Antibacterial activity of a grape seed extract and its fractions against Campylobacter spp.

In this study, the antibacterial activity of a grape seed extract (GSE) was examined against different Campylobacter strains. Growth inhibition was in the range from 5.08 to 6.97 log CFU/ml, demonstrating the strong capacity of the GSE to inhibit Campylobacter growth. Further dilution of the extract showed a minimal inhibitory concentration (MIC) of 20 mg/l and a minimal bactericidal concentration (MBC) of 60 mg/l against Campylobacter jejuni. GSE was fractioned by RP-HPLC and phenolic composition was determined by HPLC-DAD and HPLC-MS. The phenolic profile of GSE mainly consisted on flavonols, phenolic acids, catechins and proanthocyanidins, and anthocyanins. Among them, catechins and proanthocyanidins were the major compounds, representing 77.6% of total phenolic compounds determined. The analysis of the antibacterial activity against C. jejuni of the collected fractions showed that phenolic acids, catechins and proanthocyanidins were the main responsible of the behavior observed. These results showed that identification and quantification of the individual phenolic compounds of GSE could be feasible to standardize the production process to obtain an enriched extract potentially useful to control Campylobacter in the food chain.

► Grape seed extract (GSE) had a strong capacity to inhibit Campylobacter growth. ► Catechins were the major compounds in GSE representing 77.6%. ► Phenolic acids and catechins were the main responsible of antibacterial activity.