Juice quality and polyphenol concentration of fresh fruits and pomace of selected Nova Scotia-grown grape cultivars

Juice, fresh fruit and pomace of 10 selected Nova Scotia-grown grape cultivars (five table and five wine cultivars) were evaluated for their physicochemical parameters and major phenolic compounds to determine their suitability in use for developing functional beverages. Colour intensity, total soluble solids, total anthocyanin concentration and antioxidant capacity were significantly higher in juice of wine grape cultivars than in juice of table grape cultivars. Titratable acidity was not significantly different among the juice of the two categories. In juice, a high positive correlation was observed between total phenolic concentration measured using Folin-Ciocalteu assay and antioxidant capacity measured using oxygen radical absorbance capacity (ORAC) (r = 0.87) and ferric reducing antioxidant power (FRAP) (r = 0.95). Flavan-3-ols, stilbenes and anthocyanin concentrations were significantly higher in fruits of wine grape cultivars, while the distribution of flavonols was highly variable in two categori...