Natural Product-Oriented Reformulation of Muffins: Sourdough Fermentation with Leuconostoc citreum DSM 5577 for Sugar Reduction

This study aims to investigate the ability of sourdough fermented with Leuconostoc citreum (Lc) DSM 5577 to produce mannitol and to evaluate its impact in reduced-added-sugar muffins. Compared to a standard recipe with 100% sugar, two formulations with 50% and 0% added sugar were used. Sourdough fermented for 24 and 48 h was incorporated at different levels (30% and 50%) into muffins. The effects on the technological properties, as well as mannitol, carbohydrate, and organic acid contents, microbiological profile, and sensory characteristics, were evaluated. The optimum sourdough fermentation time was 48 h, which produced high levels of lactic acid (2.25 mg/g), acetic acid (4.61 mg/g), and mannitol (6.27 mg/g). The use of 50% sourdough fermented for 48 h in the muffin formulations produced the greatest amount of mannitol (3.57 mg/g). FTIR spectroscopy revealed compositional changes associated with fermentation in the sourdough and muffins. The baking tests demonstrated a reduction in baking losses without compromising specific volume. Muffins containing 50% added sugar and 30% sourdough fermented for 24 h were the most appreciated in terms of taste and flavor. The results suggest that sourdough fermented with Lc DSM 5577 may be an innovative approach for a natural reduction in sugar in muffins while preserving their technological quality.