SODIUM-CHLORIDE ENHANCES THE POTENTIAL LEAVENING ABILITY OF YEAST IN DOUGH

When Saccharomyces cerevisiae FL2209, a baking strain isolated from commercial compressed yeast, was cultured in YPS medium composed of 2% Bacto-yeast extract, 4% Bacto-peptone, 2% sucrose, 0·2% sucrose, 0·2% KH2PO4 and 0·1% MgSO4.7H2O (pH 6·0), it showed higher leavening abilities in three types of doughs compared to those of the commercial compressed yeast, but not in sweet dough. Addition of NaCl to YPS medium resulted in the increase of leavening abilities in all of the doughs tested. Effects of NaCl were further investigated in seven other yeast strains including six S. cerevisiae strains and one Torulaspora delbrueckii strain. NaCl commonly elevated the leavening abilities of five-maltose-fermenting S. cerevisiae strains in dough without addition of sugar. Sweet dough leavening was stimulated by NaCl in only one strain of S. cerevisiae. Leavening abilities of T. delbrueckii were reduced when cultured in the presence of NaCl. YPS medium with the addition of NaCl was shown to be available to estimate the potential leavening abilities of most yeast strains. © 1993 Academic Press Limited.