Abstract:This study utilized anthocyanidin（ ACN） extracted from the pomace of Vitis amurensis Rupr. after juice pressing and soybean insoluble dietary fiber（ SIDF） extracted from soybean by-product okara as raw materials to develop a kind of anthocyanidin dietary fiber steady-state beverage. The photo-thermal stability of the beverage was assessed,and the probiotic effect was evaluated through in vitro fermentation tests. The results demonstrated that by adding the ACN-SIDF steady-state stock solution to achieve an ACN concentration of 12.0 mg/100 mL,with soluble solids at 8%,total acid content at 0.25%,xanthan gum at 0.15%,and fixed grape essence at 0.1%,the SIDF content in the beverage reached 360.0 mg/100 mL,generating optimal taste. Compared to the anthocyanidin-only beverage,the photostability and thermal stability of the steady-state beverage increased by 20.87% and 26.05%,respectively. Co-fermentation of exogenous intestinal bacteria with the beverage resulted in decreased pH values and production of short-chain fatty acids（ SCFAs）. Notably,the steadystate beverage exhibited a stronger capacity for SCFAs production and a lower pH value,indicating its superior probiotic effects.