Influence of Pasteurization on Total Phenols Content and Antioxidant Capacity of Prunus persica L. Juices

Abstract

Peach and nectarine (Prunus persica ) production has an important place in the world, being the most important fruit after apple crops in the European Union. Because the fruits are perishable, it is desirable to valorize them as juice. Seven peaches and three nectarines cultivars grown in the N-W part of Romania were investigated for quality parameters, volatile profile, total phenols content and antioxidant capacity. The volatile composition of peach and nectarine cultivars was determined via the ITEX/GC-MS technique, the main volatile compounds belonging to alcohols and aldehydes. Another objective was to obtain the pasteurised juices from these fruits and to investigate the best time of pasteurisation in order to identify the most valuable cultivar from the perspective of total phenols content and its antioxidant capacity. For a better interpretation of results and a proper discrimination between cultivars, according to the total phenols content and antioxidant capacity, the multivariate analysis, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied. The peach cultivars showed the highest content in total phenols compared with nectarine. From peach cultivars, the highest concentration was recorded in ‘Southland’ (47.49 ± 0.14 mg GAE 100 g^-1 FW) and from nectarine cultivars in ‘Romamer’ (16.28 ± 0.83 mg GAE 100 g^-1 FW). The highest antioxidant capacities were recorded in ‘Southland’ peach in the case of both methods (DPPH and FRAP). The results showed that ‘Southland’ peach and ‘Romamer’ nectarine pasteurised juices are the best from the point of view of total phenolic compounds content with high antioxidant capacity.