Abstract:The lotus seed red-skin is rich in various bioactive compounds, but its application is limited due to its bitter taste. In this study, a flavonoids-enriched extract with a purity of 90% was prepared and added to steamed buns. The specific volume, color, textural properties, sensory evaluation and in vitro digestion characteristics of steamed buns were measured. The results showed that the red-skin flavonoid extract exhibited a strong inhibitory effect on α-glucosidase. With the increase in the mass fraction of lotus seed red-skin flavonoids, the specific volume of the steamed buns first increased and then decreased, while the L* values of the crust and crumb gradually decreased. Hardness, adhesiveness, and chewiness gradually increased, while stickiness, springiness, elasticity, and cohesiveness gradually decreased. Sensory evaluation showed that steamed buns with 0.5% and 1.0% mass fractions of lotus seed red-skin flavonoids were highly acceptable, with no obvious bitterness or other undesirable flavors, have a better shape, improved resilience, and a stronger bite. Furthermore, lotus seed red-skin steamed buns effectively slowed the starch hydrolysis rate, significantly reducing the content of rapidly digestible starch while increasing the content of resistant starch. Compared with regular white steamed buns, the steamed buns with 2.0% mass fraction of red-skin flavonoids showed a significantly lower estimated glycemic index (eGI), comparable to that of commercially available low-glycemic index (GI) bread.
