Grape seed flour of different grape pomaces: Fatty acid profile, soluble sugar profile and nutritional value

The aim of this study was to determine fatty acid and soluble sugar profiles of the grape seed flour originated from non-fermented dried pomace of international and autochthonous grape varieties aiming to estimate their potential nutritional value. The grape seed flours were obtained from the grapes harvested in technological maturity. It has been shown that grape seed flours contained significant quantities of unsaturated fatty acids (UFAs), especially linoleic fatty acids, whose content ranged from 61.15 - 83.47 %. Oleic acid mostly contributed to the content of monounsaturated fatty acids, while the stearic acid was the most abundant saturated fatty acid (SFA). Polyunsaturated fatty acids, mainly ω-6 FAs, were the most represented. The tested grape seed flours had the high UFA/SFA ratio (3.63-11.09), low atherogenicity (0.04-0.13) and thrombogenicity (0.16-0.47) indices. Fifteen different sugars were found in analysed samples with the total concentration ranged from 40588 to 91319 mg/kg seed with fructose and glucose as the most abundant. Principal component analysis based on the content of FAs and soluble sugars revealed unique composition of the seed flour of Prokupac variety. These findings indicate that the tested grape seed flours could be a good source of nutritionally valuable FAs and sugars that can play an important role in the formulation of new functional food products.