Micronization of wheat bran: influence on the quality and starch digestibility of dietary fiber-enriched steamed sponge cake

Exploring an ideal carrier for superfine wheat bran dietary fiber is important for maximizing its health benefits. This study evaluated the batter rheology, texture, gel network structure, and starch digestibility of steamed sponge cake (SPC) enriched with wheat bran of different particle sizes at 10%, 20%, and 30% addition. The results indicated that to maintain the quality (appearance, texture, and sensory attributes) of SPC without significant compromise, the addition of coarse bran (84‒1110 μm) should not exceed 10%. However, for superfine wheat bran (19 μm), increasing the addition from 10% to 30% did not impair the hardness, springiness, overall acceptability, gas cell structure, and relatively intact starch gel network of SPC. Moreover, the starch digestibility of SPC with 30% superfine wheat bran decreased from 90.1% (control) to 81.6%, and resistant starch content increased by 85.9%. This study suggests that products not requiring gluten development could be ideal carriers for high levels of micronized dietary fiber.