Stability and biological activity of Merlot (Vitis vinifera) grape pomace phytochemicals after simulated in vitro gastrointestinal digestion and colonic fermentation

• Published in: Journal of functional foods 2017-09, Vol.36, p.410-417
• Main Authors: Corrêa, Rúbia C.G., Haminiuk, Charles W.I., Barros, Lillian, Dias, Maria Inês, Calhelha, Ricardo C., Kato, Camila G., Correa, Vanesa G., Peralta, Rosane M., Ferreira, Isabel C.F.R.
• Format: Article
• Language: English
• Subjects: Antiproliferative effects; In vitro fermentation; In vitro gastrointestinal digestion; Merlot grape pomace; Phenolic compounds
• ISSN: 1756-4646; 2214-9414
• DOI: 10.1016/j.jff.2017.07.030

•Grape pomace is an abundant and accessible by-product with potential bioactivities.•The in vitro digestion drastically altered the crude extract’s phytochemical profile.•Such alterations caused the decrease of antioxidant and antibacterial effects.•Microencapsulation procedures could preserve grape pomace phenolics’ bioactivities.•The simulated colonic fermentation improved the extract's antiproliferative potential. Grape pomace is an abundant/accessible food industry by-product that contains a wide range of phenolic compounds, which have been related to several health benefits and bioactivities. The aim of this study was to mimic the gastrointestinal digestion and the colonic fermentation of Merlot grape pomace, in order to unravel possible phytochemical contents reductions and the processes associated with them, as a tentative to relate the phenolic compound profiles of the extracts with their biological properties. LC-DAD-ESI/MS suggested that the in vitro digestion process promoted drastic qualitative and quantitative reductions in the phenolic compounds profile of the Merlot grape pomace crude extract. Such alterations could be related to the decreases of some bioactivities of the extract, which seems to be the case of antioxidant and antibacterial properties, although not in a directly proportional manner. However, the simulated colonic fermentation seems to have a positive effect over the extract's antiproliferative potential.