The aim of this study is to evaluate the effects of different types of sourdough (I to IV), developed with a specific starter culture (including Lactiplantibacillus plantarum, Levilactobacillus brevis, and Candida famata), on bread fermentation performance and shelf-life. Real-time tracking of multiple parameters (pH, dough rising, ethanol release, and total titratable acidity) was monitored by a smart fermentation oven. The impact of the different treatments on the lactic acid, acetic acid, and ethanol content of the breads were quantified by high performance liquid chromatography analysis. In addition, the bio-preservation capacity of the breads contaminated with fungi was analyzed. The results show that liquid sourdough (D3: Type 2) and backslopped sourdough (D4: Type 3) increased significantly (p < 0.05) in dough rise, dough acidification (lower pH, higher titratable acidity), production of organic acids (lactic and acetic), and presented the optimal fermentation quotient. These findings were substantiated by chemometric analysis, which successfully clustered the starters based on performance and revealed a strong positive correlation between acetic acid production and dough-rise, highlighting the superior heterofermentative profile of D3 and D4. These types of sourdough also stood out for their antifungal capacity, preventing the visible growth of Aspergillus niger and Penicillium commune for up to 10 days after inoculation.

The fermentative activity of sourdoughs and their stabilities are some of the main concerns of professionals in food science. The aim of this study was to evaluate the fermenting capacity of three traditional fresh sourdoughs and their freeze-dried forms with different compositions prepared by housewives in three different regions of Morocco. A device equipped with several sensors was developed to monitor several parameters simultaneously and in real time (the pH, dough rise, loss of mass, CO₂ and ethanol release). The results showed that the duration of dough fermentation was long, ranging from 594 to 1210 min, with the specific volume ranging from 0.9 to 3.35 cm³/g⁻¹. A strong and positive correlation between dough rise and CO₂ release was observed, while ethanol release did not contribute directly to dough rise. The fresh sourdough FS1 showed better fermentative performance than the others, while the freeze-dried sourdough FDS3 was also of interest for bread making. The system used to generate the graphical fingerprints enabled us to read the main fermentation parameters directly in the same graph, as well as to compare several sourdoughs at once and choose the one best suited to our needs.

The prickly pear fruit's peel (PPP) and seed press-cake (SPC) are discarded during the pulp and the seed-oil processing. This study incorporated these two by-products in the preparation of sourdoughs and evaluated their bread-making capacities. The seed press-cake was recovered during the mechanical extraction of the seed oil, ground and used to produce S1 sourdough. The peels were milled and their puree was utilized to produce firm and liquid sourdoughs S2 and S3, respectively. The prepared sourdoughs had an average pH of 3.24 and a total titratable acidity (TTA) between 13.4 and 27.4 mL NaOH 0.1M/10g. The doughs fermented with these sourdoughs had different rising capacities (167 to 259%) and specific volumes (1.53 to 2.26 cm3/g). The sourdough-fermented doughs produced equivalent amounts of CO2. The doughs fermented with the peels sourdoughs produced more ethanol than that with press-cake sourdough. Fermented doughs had a final TTA between 7.8 and 11.5 mL NaOH 0.1M/10g and a final mean pH of 3.47. The control dough fermented with baker's yeast alone had a low final TTA of 4.5 mL NaOH 0.1M/10g and a comparable pH to that of the sourdough-fermented doughs. Our results suggest the incorporation of prickly pear by-products in sourdoughs formulation and use to inoculate bread dough to decrease food waste and improve the quality of baked products.