Quality parameters of currant berries from three different cluster positions

The challenge in the production of currants is the definition of the optimum harvest time due to successive ripening of berries over the entire length of cluster. The study focused on detecting the differences in quality parameters among individual positions of berries in the cluster. A red, black and white currant cultivar ('Rovada', 'Tsema' and 'Blanka') were selected for the experiment as they all develop long clusters and are used for fresh consumption. The berry mass, colour parameters and pH of the juice were recorded and sugar and organic acids contents were determined using HPLC. A detailed analysis of individual phenolic compounds was performed on HPLC-MS. The results of the study indicate that berries from the basal part of the cluster contain higher levels of sugars, organic acids and vitamin C in comparison with berries positioned at apical cluster sections. A similar pattern was observed for phenolic components: berries of the `Rovada' cultivar contained almost twice the amount of total anthocyanins (TA) in berries from the basal cluster section compared to berries positioned at the apical part of the cluster. The differences were even more prominent (2.8 fold more TA in basal cluster section) in black currant 'Tsema'. Significant differences in the content of all identified phenolic groups have been determined between the basal and apical position of berries in the cluster: berries from the basal part contained from 1.6 to 2.2 fold more hydroxycinnamic acids, from 1.7 to 2.2 fold more flavonol glycosides and from 1.5 to 1.8 fold more flavanols (catechin, epicatechin and procyanidin). The results of the study may be useful to the producers who strive to improve their production technology, for food and processing industry and for consumers as it was pointed out that the quality of berries at the apical part of the currant clusters is decreased compared to berries from the basal part of the cluster. (C) 2016 Elsevier B.V. All rights reserved.