Physicochemical properties and functionality of wet-type grinder-treated vegetables in gluten-free rice flour bread

This study examined the effects of incorporating wet-type grinder (WG)-treated vegetables into rice flour (RF) batter on the quality of gluten-free bread. Seven vegetables-okra, carrot, spinach, ashitaba, komatsuna, broccoli, and burdock-were evaluated at optimized levels based on fermentation expansion. WG-treated okra and carrot were particularly effective, increasing specific volume by approximately 1.8-fold and 1.6-fold, respectively, while reducing crumb hardness by up to 74% compared to the control. In contrast, other vegetables exhibited moderate or limited effects, suggesting that functionality depends on their specific compositional and structural characteristics. Crumb morphology and color reflected differences in the composition of vegetable polysaccharides and pigments. The improvements in batter rheology and bread quality suggest enhanced functional interactions between WG-treated vegetable components and the RF matrix. Overall, these findings provide a physicochemical basis for using vegetable-derived hydrocolloids to improve the structure and quality of gluten-free systems.