Effect of Stevioside and Its Related Compounds on the Induction of α-Amylase Biosynthesis

Abstract

Effects of 6 kaurene glucosides on α-amylase biosynthesis in barley seeds and malts were investigated. When barley seeds and malts were incubated with steviolbioside, rebaudioside B, stevioside A₃, dulcoside A, rebaudioside C and stevioside, activities of α-amylase extracted from the incubated mixtures were found to be remarkably higher than those of the incubates without the glucosides. These compounds also induced α-amylase in embryoless barley seeds, showing a remarkable increase of reducing sugar content. However, the concentrations needed to induce the activity were much higher than that of GA₃. Iso-steviol did not show such activity. This increase in α-amylase activity was presumed to be based on the same mode of action as steviol.