Grape pomace-based beverage: Study of the potential antidiabetic function in humans and possible implications of phenolic metabolites during postprandial state

MOSSE, JUANA I.; YUSTE SILVIA; FERNÁNDEZ, LAURA; MOTILVA MARÍA JOSÉ

Logroño

Congreso; II International Congress on Grapevine and Wine Science; 2023

Instituto de Ciencias de la Vid y el Vino

In line with the principles of the circular bio-economy,this study was carried out using wine by-products as a functional foodingredient. The skins and seeds obtained from the winemaking process ofTempranillo and Graciano cultivars were conditioned to prepare a phenolic-richbeverage, containing anthocyanidins (58 mg/100 mL), flavonols (11.3 mg/100 mL) andflavan-3-ols (8.5 mg/100 mL) as main phenols. These compounds have beenextensively studied due to their probed health properties, including antidiabeticeffects in part attributable to their capacity to modulate glucose metabolism. Tostudy the potential of wine by-products (skin and seeds) as functionalingredients, we have evaluated the postprandial glycemia response after theintake of the phenolic-rich beverage. For this, 10 healthy adults (50% female)between 24-46 years participated in a three independent days’ pilot trial.Under fasting conditions and after following a low-polyphenols diet, thepostprandial glycaemia of volunteers was measured after three differentinterventions: (i) water + sugar, (ii) beverage + sugar and (iii) beverage + water.In parallel, blood samples were collected with dried blood spot cards duringpostprandial state (0-2 h) and after 4, 6 and 12 h of the oral challenge.Despite blood glucose levels tended to decrease after the intake of thebeverage, these changes were not statistically significant due to theinter-individual variability. In part, we attribute this absence of significanceto the marked differences observed between volunteers in the way they respondto the sucrose challenge. The bioavailability and metabolism of phenoliccompounds ingested with the beverage was evaluated through chromatographicanalysis (HPLC-ESI-QqQ-MS/MS). Blood phenolic metabolites at each point of thepostprandial glycaemia were identified to establish a connection between theirblood concentration and the regulation of glycaemia.