Food matrix is known to interact with some dietary constituents during digestion. These interactions may potentially affect the metabolism and bioavailability of some plant foods bioactives, and as a consequence modulate their biological effects. In this context, the aim of this study was to determine the effect of food matrix on the bioavailability of apple polyphenols and the ability of the circulating metabolites of apple flavanols to modulate the cell response to a postprandial metabolic stress induced acutely in minipigs. Adult yucatan minipigs (n=5, male) were assigned to a random treatment sequence of high-fat meals non supplemented or supplemented with either 250g of raw apple, 250g of apple puree or 1.4g of apple polyphenols extract, with a 7-days washout period between treatments. Each supplementation provided 155mg of flavanol monomers (catechin and epicatechin). At each treatment, fasting- and 1h-, 2h-, 3h-postprandial blood samples were collected. At each time point, the concentrations in flavanol monomers were evaluated on hydrolyzed serum using UPLC-Q-TOF MS. Results show that whatever the administration mode, the peak of flavanol monomers was obtained 3h after the intake. During the postprandial phase, a high fat load is known to induce both oxidative and inflammatory stress, leading to an acute activation of endothelial and immune cells. Through an ex vivo approach, using the sera sampled from pig during the post-prandial period, we investigate the capability of flavanol metabolites to modulate this acute activation in cell experiments. Endothelial cells isolated from porcine aorta are exposed to fasting and 3h-postprandial sera for 4 hours prior to perform an adhesion assay of monocytes to endothelial cells. In addition, on porcine PBMCs isolated from 3h-postprandial blood sampleswe assess the effect of apple flavanols on the gene expression profile using microarray analysis. These experiments are still ongoing and results will be available soon