Phenolic profile and biological activity of table grapes (Vitis vinifera L.)

Abstract

Table grapes are largely produced and consumed in the Mediterranean area. Furthermore, in the last years, the commercial interest in table grapes and other non-alcoholic grape products has notably increased worldwide. In addition to the nutritional aspects, polyphenol compounds in fresh grapes could exert positive effects on human health. The aim of this study was the characterization of the phenolic pattern of sixteen grape varieties and the evaluation of the associated antioxidant capacity and anti-inflammatory activity at gastric level. The methods used were: 1) Folin-Cocalteau's assay for the quantification of total polyphenol content; 2) High-Performance Liquid Chromatography (HPLC) coupled with Diode-Array Detector (DAD) to perform the quantitative analysis of grapes phenolic fraction 3) DPPH (1,1,-diphenil-2-picrylhydrazyl) spectrophotometric assay for the assessment of radical scavenging activity; 4) assessment of IL-8 release from human gastric epithelial cells to evaluate the anti-inflammatory activity of grape extracts. Some grapes, including seedless varieties, showed that the phenolic pattern was highly correlated with the biological activities, and, in particular, with peel and seeds portion. These results suggest that selected grape varieties could represent, also for consumers who do not drink wine, a source of healthy compounds potentially able to counteract oxidative stress and gastric inflammation.