Impact of enzymatic treatment on the blackcurrant (Ribes nigrum L.) polyphenols in juice and press-residue

The aim of this study was to determine the effect of pre-pressing enzymatic (pectinase) treatment of blackcurrant mash on the juice yield and content of polyphenolic compounds in juice and press-residue. The fruits of blackcurrant (Ribes nigrum L.) cultivars 'Ben Lomond', 'Pamyati Vavilova' and 'Karri' were collected at the experimental plots of Polli Horticultural Research Centre of Estonian University of Life Sciences (587'26''N, 2532'43''E). The mash enzyme treatment with Panzym Univers enzyme preparation was dosed according to the instructions of manufacturer. The mash enzyme treatment improved juice yield depending on the cultivar up to 44.3% compared to non-treated juice. Though, the contents of polyphenolic compounds varied according to treatment in comparison with freshly frozen berries before pressing, showing up to 18% decrease of anthocyanin content in enzymatic juice and up to 29% increase of polyphenols in enzymatic pressresidue. The contents were not significantly different in treated and nontreated juice.