Abstract:To determine the optimal fermentation process parameters for the kombucha-fermented Sargassum fusiforme beverage，this study used S. fusiforme from Dongtou，Wenzhou as the main raw materials. The beverage was produced by inoculating the kombucha starter culture. Based on single-factor experiments，response surface methodology was employed to optimize the process，using total acid content and sensory score as evaluation indices. The effects of inoculation ratio，initial sugar content，fermentation temperature，and fermentation time on the quality of the kombucha-fermented S. fusiforme beverage were investigated，and the optimal process parameters were determined. The results showed that under the conditions of 9% kombucha inoculum，a fermentation period of 11 d，initial sugar content of 11%，and fermentation temperature of 31 ℃，the total acid content of the beverage was 2.7 mg/mL，and the sensory score was 87.6. These values were close to the results of three validation experiments，indicating a high degree of fit of the regression model. During fermentation，a gradual decline in pH and a continuous increase in titratable acidity were observed，accompanied by an increase in both total phenolic and flavonoid contents at the early stage，suggesting that kombucha fermentation facilitated the release of phenolic and flavonoid bioactive compounds from S. fusiforme.