Abstract
This study aimed at understanding the effect of additional ingredients (baker's yeast, macerated pears, grape must, honey, or water from macerated pears) on the microbiota and biochemical characteristics of durum wheat-based sourdough. One dough prepared using only flour was used as the control (control-dough). Compared to the control-dough, doughs containing additional ingredients showed higher (P smaller then 0.05) cell numbers of lactic acid bacteria after the first fermentation. Constant pH of ca. 4.0 was found after two (macerated pears or water pears-doughs) to seven (control-dough) back-slopping steps. The use of additional ingredients caused lower microbial diversity, after the first fermentation and in mature sourdoughs. Regardless of the type of ingredient used, OTU belonging to the genus Lactobacillus represented more than 95% of the total Firmicutes in mature sourdoughs. Some metabolic capacities of microbial community of the mature sourdoughs were linked to the additional ingredient. Based on culture-dependent method, Lactobacillus plantarum and Saccharomyces cerevisiae dominated in all the sourdoughs. However, the sourdoughs showed different strains of these two species. Other lactic acid bacterium species were associated to baker's yeast, grape must and macerated pears. The different microbial composition was correlated (r greater then 0.7, P smaller then 0.05) with several biochemical characteristics of the sourdoughs (e.g., free amino acids and their derivatives). © 2016 Elsevier Ltd