Antioxidant Activity and α-Glucosidase Inhibitory Effect of Jerusalem Artichoke (Helianthus tuberosus) Methanol Extracts by Heat Treatment Conditions

Abstract

This study investigated the changes of antioxidant activity and α-glucosidase inhibitory effect of Jerusalem artichoke (Helianthus tuberosus) 100% methanol extracts by various heat treatment. The contents of total phenolic and flavonoid compounds in methanol extract tended to increased gradually with the rise of temperature to 180℃. The maximum yield of gallic acid (51.52 ± 2.17㎎/g extract weight) and quercetin (13.39 ± 0.03㎎/g extract weight) were obtained with extraction temperature of 180℃ for 120min. In addition, the improving extraction efficiency resulted in the increased biological activities, such as electronic donation ability (EDA, 90.36 ± 0.57%), reducing power (Abs 1.14) and α-glucosidase inhibitory effect (92.14 ± 1.14%). Overall, the results of this study indicate that the optimum conditions for the extraction process were an extraction temperature at 180℃ for 120 min, and will provide the basis for future research on the improving extraction yield of phenolic and flavonoid compounds.