Abstract
The activity of an enzyme degrading rutin in tartary buckwheat (Fagopyrum tataricum) seeds and common buckwheat (Fagopyrum esculentum) seeds was compared. HPLC analysis showed that rutin was contained 100 times higher in tartary than in common buckwheat flour. On addition of water to tartary buckwheat flour, most of rutin decomposed to quercetin rapidly. The crude rutin degrading enzyme extracted with 0.02M acetate buffer (pH5) from tartary buckwheat showed 680 times higher activity than that from common buckwheat. The crude enzyme did not act on quercitrin and naringin. The crude enzyme from tartary buckwheat was also accompanied by little β-glucosidase and a-rhamnosidase activities. From these results, it was suggested that this enzyme is specific for rutin. This enzyme was unstable above 70°C, below pH3 and above pH7, and inactivated by protein denaturants.
