A reduction inhibitory agent for active oxygen eliminating activity which
comprises cyclotetrasaccharide i.e., cyclo{6}-.alpha.-D-glucopyranosyl-(1
3)-.alpha.-D-glucopyranosyl-(1 6)-.alpha.-D-glucopyranosyl-(1
3)-.alpha.-D-glucopyranosyl-(1), as an effective ingredient, a method for
inhibiting the reduction of active oxygen eliminating activity which
comprises incorporating either cyclotetrasaccharide or the reduction
inhibitory agent into plant edible products and/or plant antioxidants,
and a composition where the reduction of active oxygen eliminating
activity of the plant edible products and/or plant antioxidants has been
satisfactorily inhibited by the method.
