Flavonoid Contents of Whole Fruit and Various Tissues of a New Acid Citrus, ‘Niihime’

Abstract

A new acid citrus, ‘Niihime’, Tachibana (Citrus tachibana Tanaka), and Shiikuwasha (C. depressa Hayata) were examined for flavonoid contents of the whole fruit and tissues (flavedo, albedo, vascular tissue, segment membrane, juice vesicle, and seed) at the maturing stage. Seven flavonoid substances, eriocitrin (ECR), narirutin (NRT), hesperidin (HSP), neoponcirin (NPNC), nobiletin (NBL), sinensetin (SNT) and tangeretin (TNG), were determined using HPLC analysis. The three acid citrus contained all flavonoid substances determined in the present study, except for no detection of ECR in Shiikuwasha. ‘Niihime’ contained more ECR, NRT, NPNC, and SNT than Tachibana and Shiikuwasha. Total contents of the seven flavonoids in the fruit of ‘Niihime’ were higher than in Tachibana. On the contrary, ‘Niihime’ contained significantly less NBL (65%) than Shiikuwasha, while it was similar to Tachibana. ‘Niihime’ contained significantly less TNG (30 and 24%, respectively) than Tachibana and Shiikuwasha. Flavonoid contents in individual fruit parts of ‘Niihime’ were as follows: ECR, SNT, NBL, and TNG were highest in the flavedo, NRT and NPNC were highest in vascular tissue, and HSP was highest in vascular tissue and the albedo.