Juice was pressed from black currants without enzyme treatment
(NEB = Non-Enzymatic Berry) followed by re-pressing of the residue with
enzymes (EPR = Enzymatic Press Residue) and the results were compared to
the conventional enzyme-aided berry pressing (EB = Enzymatic Berry).
EPR-juice had 9- and 5-fold higher contents of phenolic compounds
compared with the NEB- and EB-juices, respectively. Effect of the low
content and stability of phenolics was noticed as loss of the visual
color in the NEB-juice during storage. The decrease in monomeric
anthocyanins and the increase in phenolic acids were most severe in the
NEB-juice, whereas the most significant decline in hydroxycinnamic acid
derivatives occurred in the enzyme-treated juices. Storage in light
induced less change in the phenolic composition in EPR-juice than in the
two other juices. The study gave new knowledge on changes in individual
metabolites, in sensory properties and in the shelf life of berry
juices.