Involvement of flavonoid oxidation with chlorophyll degradation by peroxidase in Wase satsuma mandarin fruits.

摘要

Effects of flavonoid pigments on chlorophyll (Chl) degradation by Chl degrading peroxidase in the flavedo of satsuma cv. Okitsuwase fruits were studied. Chl was degraded when hydrogen peroxide was added to a reaction mixture containing Chl and a phosphate buffer extract from the flavedo. Chlorophyllide, which was formed by the action of chlorophyllase in the extract, was also degraded, while flavonoid content decreased concomitantly. Analyses of the flavonoids with HPLC showed that hesperidin and narirutin were the major flavedo flavonoids; the former decreased significantly, whereas the latter showed almost no change during the Chl degradation reaction. In ethylene treated fruits, flavedo hesperidin content decreased with degreening during storage, indicating that flavonoid oxidation by Chl degrading peroxidase could be involved in Chl degradation.