Fermentation Unlocks the Functional Role of Amaranth in Modulating Wheat/Amaranth Sourdough Microbiota and Inhibiting Yeast Growth of Refrigerated Doughs

This study focuses on the development of refrigerated doughs without chemical preservatives to obtain a clean-label product. Sourdough-based strategies were applied to replace conventional preservatives, using both spontaneous flour fermentation and a defined starter culture of Lactiplantibacillus plantarum CIDCA 8327. In parallel, a partial substitution of wheat flour with 7% amaranth flour was evaluated. To monitor fermentation, pH, titratable acidity, and viable microorganism counts were determined in the sourdoughs, along with culture-independent analyses of microbial communities in two independent spontaneously fermented trials. Dough discs prepared from these sourdoughs were analyzed for pH, titratable acidity, and viable microorganisms, and shelf life was determined based on the appearance of visible mould during refrigerated storage. No substantial differences were observed in the physicochemical parameters of the sourdoughs; however, significant differences in microbial communities were detected, influenced by both amaranth addition and wheat flour batch variability. Dough discs prepared with amaranth flour and spontaneous fermentation showed an extended shelf life and lower mould and yeast counts during refrigerated storage. The use of the starter increased shelf life compared to non-fermented doughs but was less effective than spontaneous sourdough with amaranth. Overall, these results highlight the potential of sourdough technology and amaranth flour for developing clean-label refrigerated products.