Effect of invertase activity on the leavening ability of yeast in sweet dough

Abstract

Leavening ability of yeast in dough and invertase activity were determined in 32 strains of Saccharomyces cerevisiae. By the regression analysis of the data obtained, participation of invertase in sweet dough leavening was less than the osmotolerance of yeast cells. Four representative strains were selected and further investigation was conducted in these strains. Along with the concentration ofNaCl added to the growth medium, sweet dough leavening increased but invertase activity changed independently. Acid treatment of the cells with diluted HCl deprived the yeast cells of invertase activity in the four strains, and elevated leavening ability was observed in sweet dough in the two strains but not in the other two strains. Addition of purified invertase to the dough gave a limited effect on the sweet dough leavening. These observations suggested that invertase activity was not obligately related to the leavening ability o f sweet dough.