Abstract
Suioh is a new sweet potato cultivar with edible leaves (leaf blades and petioles). This study examines the effects of different cooking methods on the physiologically functional components in the Suioh leaves. The leaf blades and petioles were cooked by steaming, simmering, boiling and stir-frying. The contents of lutein, total caffeic acid derivatives (TCQA), 3, 4, 5-tri-caffeoylquinic acid (3, 4, 5-triCQA) and total polyphenol (TP) in the cooked leaves were then determined, and the antioxidative activities of the cooked leaves were also evaluated. The lutein content of the cooked leaf blades was highest when stir-fried. The cooked leaf blades also contained 3, 4, 5-triCQA, and the TP content of the leaf blades remained high when boiled or simmered. The antioxidative activity of the cooked leaves was correlated with the contents of TCQA and TP. These results can be used to design recipes with high contents of physiologically functional components in cooked foods.
