Effects of lactic acid bacteria on the properties of sour dough bread

The bread baked with sour doughs fermented with the heterofermentative organisms, and thus containing the highest amounts of acetic acid, showed the best ability to prevent growth of the mould Eurotium rubrum.

Abstract

The effects of 13 different sour dough bacteria and a commercial sour dough starter from West Germany on the properties of sour dough bread were studied. As reference, a rye bread with lactic acid as souring additive was used. An expert taste panel, trained specifically for bread, was used to judge the bread. All organisms produced acids adequate for a good bread quality. However, the sour doughs fermented with the heterofermentative Lactobacillus spp. had higher acid equivalents, lower pH-values and also gave bread with stronger taste of acidity and acetic acid than those fermented with the homofermentative organisms. Correlation coefficients between taste values and analyses data also show that acetic acid has a great influence on the bread taste, whereas lactic acid seems to be of less importance. Two breads were judged to be somewhat different in taste compared to the others, namely those with sour doughs fermented with Lactobacillus alimentarius and Leuconostoc dextranicum. On comparison with the reference bread, the sour dough bread was judged to have a stronger taste of acidity and also a more aromatic and crispy crust. The bread baked with sour doughs fermented with the heterofermentative organisms, and thus containing the highest amounts of acetic acid, showed the best ability to prevent growth of the mould Eurotium rubrum.