High Sugar Content and Sweetness in Bread with First Fermentation at −1 °C without Ice Crystal Formation

We hypothesized that the first fermentation of bread dough at −1 °C, a temperature within the superchilling zone but that does not produce ice crystals, would alter metabolite composition compared to conventional methods, thereby improving palatability. This study investigated the impact of −1 °C first fermentation (−1 °C_FF) on the metabolite profiles and palatability in bread production. Bread subjected to −1 °C_FF for 72 h exhibited significantly higher glucose and fructose contents compared to bread produced using a normal first fermentation (NFF, 28 °C for 1 h) or a 4 °C first fermentation (4 °C_FF) for 72 h. This increase in sugar content may be attributed to the inhibition of yeast sugar uptake or alcoholic fermentation at −1 °C. Sensory analysis revealed that the −1 °C_FF bread was perceived as sweeter than the NFF and 4 °C_FF breads. These results suggest that −1 °C_FF represents a novel fermentation method capable of enhancing the sweetness of bread.