Effects of oat flour on rice flour and fermented rice cake: Processing properties, quality attributes, and starch...

The rising incidence of diet-related chronic and celiac diseases underlines the demand for high-quality, functional gluten-free products that improve health. This study systematically evaluated the impact of oat flour (OF) substitution at different levels on the mixed flour and the final FGCs (OF 0%, OF 10%, OF 20%, OF 30%, OF 40%), along with underlying mechanisms. OF substitution enhanced the system's water-binding capacity, the integrity of starch granules, and viscoelasticity, while inhibiting gelatinization and promoting short-term retrogradation, as evidenced by reduced pasting enthalpy and increased pasting temperature and setback value. OF substitution increased FGCs' specific volume and hardness, with springiness peaking at a 20% substitution (0.906). OF substitution resulted in a denser and more homogeneous microstructure of FGCs. The SPME-GC-MS analysis demonstrated that OF substitution introduced novel volatile compounds, especially the unique nutty aroma. These physicochemical changes induced varied sensory evaluations, with the OF 20% achieving the highest overall acceptability score (7.90). During the storage period, water molecules in the OF groups were more tightly bound, thus delaying the retrogradation rate. In addition, OF promoted the formation of starch lipid complexes and retarded the rate of starch hydrolysis. Overall, OF is a promising ingredient for developing functional gluten-free cereal products with enhanced quality and shelf life.