Influence of cultivar, storage time, and processing on the phenol content of cloudy apple juice.
Summary The aim of this work was to investigate the influence of cultivar and storage time on the total phenol content (TPC) of three actual apple cultivars (Topaz, Pinova, Pink Lady) and three autochthonous apple cultivars (Ruzmarinka, Ljepocvjetka, Paradija) as well to determine their physical and chemical characteristics. Total phenol content has been determined by Folin- Ciocalteu reagent during cold storage at 1 °C, for 60 days. Changes of apple juice samples phenolics in relation to oxidation time after pressing (0 hours, 2 h and 4 h) were examined. A significant variation in content of phenols in apple cultivars under investigation was noted. Paradija, autochthonous apple contained the highest content of phenols (1.003 g GAE/L), while Topaz, actual apple cultivar had the lowest content (0.596 g GAE/L), during the storage time. TPC of apple cultivars stayed at a relatively constant level during the storage, with the exception of Pink Lady and Paradija apples, where TPC changed significantly during cold storage. The level of TPC in cloudy apple juice samples of all apple cultivars decreased during the oxidation time after pressing.