A low pH does not determine the community dynamics of spontaneously developed backslopped liquid wheat sourdoughs but does influence their metabolite kinetics

This study dealt with the influence of a crucial pH value of 4.0 on the microbiota of spontaneously fermented backslopped liquid wheat sourdoughs. Two spontaneously fermented wheat sourdough fermentation experiments
were carried out, onewithout control of the pH and one with the pH kept constant at pH 4.0, both during nine backslopping steps. In each case, two additional backslopping steps were carried out,with the pH kept constant
at 4.0 and with free pH, respectively. Keeping the pH constant at 4.0 changed the microbial community dynamics and metabolite kinetics of the sourdough fermentations. A slower prevalence of sourdough-specific Kazachstania yeasts occurred. Nevertheless, in both experiments, Lactobacillus fermentum, Lb. plantarum/pentosus/paraplantarum, and Kazachstania exigua/bulderi/barnettii prevailed ultimately. The lactic acid and ethanol concentration profileswere affected positively by keeping the pH constant at a minimumof 4.0 aswell as the
L- and D-lactic acid ratio profile, a potential biologicalmarker for sourdough stability andmaturity. Also, the concentration and diversity of acetate esters and their precursors, in particular isoamyl acetate and isoamyl alcohol, were affected negatively by the pH control, indicating the role of pH stress in the sourdough aroma formation.

Jaar van publicatie:2016

Trefwoorden:wheat sourdough, pH evolution, Community dynamics, Lactic Acid, ethanol, ester

CSS-citation score:2