Optimization of sourdough fermentation with Lactobacillus brevis and baker's yeast

Dough fermentation kinetics at 30 degreesC for 20 h and bread characteristics have been studied with single or mixed commercial starters containing Lactobacillus brevis and baker's yeast (Saccharomyces cerevisiae). When starters were mixed, yeast growth in dough and ethanol production were reduced but more glycerol (80%) and acetic acid (55%) were formed but lactic acid was constant. Dough fermentation with mixed starters also produced more aroma compounds and, as determined by bread sensory analyses, higher sugar-, acid- and bitter-type flavours. When dough was fermented in parallel with single starters for 15 h at 30 degrees C, mixed and fermented for another 10 h, production of typical sourdough-type aroma was enhanced. (C) 2001 Academic Press.