Effect of rice microgreen powder and microbial transglutaminase on the baking characteristics, microstructure and functional properties of sponge cake

Increasing consumer interest in foods that deliver health benefits has driven the development of functional versions of widely consumed products such as cakes. This study evaluated the effects of substituting rice microgreen powder (RMP) for wheat flour (0–7.5% w/w) and adding microbial transglutaminase (MTGase; 0 or 0.15% w/w) on the quality and functionality of sponge cakes. RMP significantly enhanced mineral content, dietary fiber, total phenolics, and antioxidant activity, while MTGase improved microstructure and volume. Sensory analysis showed that 5% RMP and 0.15% MTGase significantly maximized overall acceptability; however, higher RMP concentrations (7.5%) reduced scores due to grassy off-flavors. Although scores declined over 7 days, all formulations remained within the acceptable range. The combined use of 5% RMP and 0.15% MTGase produced cakes with the best overall quality, featuring superior porosity and enhanced nutritional properties. These findings indicate that RMP and MTGase can be effectively utilized to develop nutrient-dense functional bakery products with refined structural properties and high consumer appeal.