Seed oils of ten traditional Portuguese grape varieties with interesting chemical and antioxidant properties

To increase the potential and better exploring of grape seeds that are an important wine-industrial waste, oils of ten traditional Portuguese grape varieties were evaluated in relation to their vitamin E content (tocopherols and tocotrienols), fatty acid profile, as well as, antioxidant properties. Our results showed that the grape-seed oils were a good source of γ-tocotrienol (499-1575 mg/kg), α-tocopherol (85.5-244 mg/kg) and α-tocotrienol (69-319 mg/kg). Concerning fatty acid profile, linoleic (C18:2cc), oleic (C18:1), palmitic (C16:0) and stearic (C18:0) acids were the predominant. Grape-seed oils demonstrated to be a good source of polyunsaturated fatty acids (PUFAs) (63.64-73.53%), whereas monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) ranged between 14.19-21.29% and 11.64-14.94%, respectively. Interesting values of DPPH and ABTS radical scavenging activities were also obtained. This study demonstrated that these seeds may be reused and their oils incorporated in other food products, taking into account the compounds with positive effects on human health that are present in their composition.

► Fatty acid and vitamin E compositions of ten grape-seed oils were determined. ► Grape-seed oils are rich in unsaturated fatty acids and particularly in linoleic acid. ► Grape-seed oils are a good source of γ-tocotrienol, α-tocopherol and α-tocotrienol. ► Grape-seed oils presented interesting DPPH and ABTS radical scavenging activities.