Abstract
The quality of Shiikuwasha (Citrus depressa Hayata) juice was improved by combining base anion exchange resin treatment and insoluble pulp addition in order to maintain the levels of polymethoxylated flavones (PMF) such as nobiletin, tangeretin, sinensetin and synephrine. Among 16 resins tested, the base anion exchange resin WA30 was selected as the best resin to decrease acidity in the juice. A treatment of 3% WA30 resin (v/v) for 30min showed a 46% decrease in acidity of the juice, thus improving sourness for sensory evaluation of healthy beverages. °Brix/acid ratio of the juice was within the range of 6.0-10.0 used for healthy beverages in the sensory evaluation. To maintain the level of PMF, 1g of insoluble pulp prepared using a centrifugal juice extractor during processing was added to 100ml WA30 resin-treated juice with decreased acidity and the mixture was homogenized. The resulting juice was fortified with 8.5% nobiletin, 16.6% tangeretin, and 15.3% sinensetin, demonstrating that the combined method of decreasing the acidity by resin treatment and adding insoluble pulp can improve sourness and maintain PMF levels.
