DIFFERENTIATION OF INTERMEDIATE PRODUCTS (CONCENTRATES AND PUREES) FROM THE HUH INDUSTRY BY MEANS OF PHENOLIC CONTENT

Concentrates and purees are intermediate products in the manufacture o f commercial fruit juices. In this paper, the phenolic content [total polyphenols (TP), ortho-diphenols (ORT) and catechins (CAT)] in a larg e number of concentrates and purees from apple and peach fruits has be en determined. The relationships TP/ORT, TP/CAT and ORT/CAT have also been calculated. TP content was found to be significantly higher in th e concentrates than in the respective purees whereas CAT content was s ignificantly higher in the puree. ORT was found to be higher in purees than in apple concentrates, but the opposite was observed for peaches . The relationships TP/ORT, TP/CAT and ORT/ CAT were higher for the co ncentrates than for the respective purees. In addition, values for ORT /CAT were higher for the peach products than for the respective apple products. The results show that these phenolic compound measurements e nable differentiation between concentrates and purees, as well as betw een the fruit juices produced from them. The main advantage of measure ments of total phenolic compounds is that they are easy to perform in a conventional laboratory, which makes them suitable for routine analy sis.