ABSTRACT
Grape canes from Vitis vinifera L. cultivars of Campania region (Italy): “Aglianico”, “Fiano”, and “Greco” were considered in order to valorise them through the extraction of phenolic compounds provided with antioxidant activity. Since many operational parameters influence the extraction process, here different extraction conditions were compared. Grape canes (5% w/v) were extracted in water at different temperatures (25, 50, 75 and 100° C) and extraction times (10, 20, 40 and 60 min). The highest yields, in terms of mg/g dry extract, were obtained by “Greco” at 100°C and 20 min: 110.51±5.46 for total phenols, 63.29±1.35 for ortho-diphenols, 77.31 ± 3.59 for tannins, and by “Greco” at 50°C and 40 min for flavonoids: 29.37 ± 0.73. The extracts from “Greco” at different temperatures showed antioxidant activity comparable to that of butylhydroxytoluene and quercetin chosen as reference compounds. HPLC analysis revealed that gallic acid and catechin were the most abundant phenolic compounds detected in the extracts.
