The Preparation of Preserved Shallot Powders and a Pilot Study of the Antioxidative Effect of Their Aqueous Extracts on the Formation of Hydroxyl Radical Species

Abstract

In order to preserve the nutrients in shallots, after harvest, various protocols, including incubation, drying or lyophilization of the shallot are developed in this study. Using aqueous extracts of ground shallot powders, this study examines the antioxidative properties of shallots on the formation of hydroxyl radical species (• OH) generated via a Fenton-type reaction. A ribose degradation assay shows that all aqueous extracts of shallot prepared in this study exhibit enhanced levels of • OH, suggesting that processed shallot, like strong reductants such as ascorbate, has a strong reducing power, which converts Fe 3+ to Fe 2+ in a Fenton's reaction and increases the levels of