Effects of Cold Fermentation and Cold Storage on Type I Sourdough and Bread Properties

The aim of this study is to provide an alternative bakery practice by evaluating the effects of cold fermentation (backslopping at 7 and 15 °C) and cold storage (stored at 7 and 15 °C) after backslopping on Type I sourdough characteristics and the technological performance of the corresponding breads. Sourdough characteristics (pH, acidity, and microbial counts), bread quality (texture and color), storage behavior, and volatile compound profiles (VoC) were investigated to compare the extent to which these treatments improve product quality. No significant difference was observed in pH and total titratable acidity among the sourdoughs. However, the fermentation quotient of the cold storage group was higher than that of the cold fermented group. Backslopping at cold fermentation temperatures (7 and 15 °C) caused a significant reduction in lactic acid bacteria counts. Conversely, cold fermentation and cold storage at 15 °C led to a significant increase in yeast counts. From a technological perspective, bread produced with sourdough backslopped at 15 °C exhibited a higher specific volume than breads produced with the other cold-treated sourdoughs. At the end of the storage period, the bread made with cold-backslopped sourdough at 7 °C had the highest hardness value, while others remained similar. Principal component analysis (PCA) of volatile compounds revealed that cold-stored sourdoughs were clustered apart from room-temperature-stored sourdoughs, mainly driven by ethyl hexanoate and hexyl acetate. Heptanoic acid was among the key VOCs contributing to the positioning of breads made with cold-stored sourdoughs in the PCA. In conclusion, these findings demonstrate that backslopping and storage at 15 °C offer an industrially relevant production strategy while improving textural properties and VoC profiles.