Akademik Veri Yönetim Sistemi
LWT-FOOD SCIENCE AND TECHNOLOGY, cilt.59, sa.2, ss.933-940, 2014 (SCI-Expanded)
The effects of clarification and pasteurization on hydrolysable tannins (HTs), condensed tannins (CTs) and antioxidant activities of pomegranate juices extracted from whole fruits and sacs were investigated. Tannin contents (53-85%) and antioxidant activities (18%) in juice from whole fruits (JFWF) were found higher than those in juice from sacs (JFS). In both juice samples, clarification led to significant decreases (15-74%) in total polyphenol, HT and CT contents as well as antioxidant activities, whereas pasteurization (1-52%) led to the increases, except for the CT contents. Similar to pasteurization, HT contents also increased (r = 0.956) as the pressure and time increased during pressing. Punicalin, a-punicalagin, punicalagin and ellagic acid hexoside were the major HTs in pomegranate juices. Among HTs, ellagic acid hexoside was the major HT in JFWF, whereas beta-punicalagin was the major one in JFS. beta-punicalagin was the most susceptible HT to clarification. Strong correlations were found between antioxidant activity values with total polyphenol contents (r = 0.824-0.926), and total HTs contents (r = 0.775-0.994) and CT contents (r = 0.592-0.956). Antioxidant activity of JFWF resulted mainly from HTs (r = 0.994), while that of JFS resulted mainly from CTs (r = 0.956). (C) 2014 Elsevier Ltd. All rights reserved.