To investigate the optimal processing parameters for Ipomoea batatas-Morus alba flavored yogurt, analyze its quality, and develop a yogurt with a unique flavor and excellent quality.

First,the process conditions—including the ratio of Ipomoea batatas powder to Morus alba juice, sugar addition, and fermentation time—were optimized through single-factor and response surface experiments, using viscosity,water-holding capacity, whey separation rate, acidity and sensory evaluation as indicators Subsequently, under the optimized process conditions, the quality of the yogurt was analyzed based on indicators such as protein, fat, non-fat milk solids, acidity, lactic acid bacteria count and mold count.

The optimal process parameters for Ipomoea batatas-Morus alba yogurt were determined as follows: A Ipomoea batatas powder to Morus alba juice ratio (m:m) of 3:5, a sucrose addition of 6% and a fermentation time of 5.0 h. Under these conditions, the sensory score of the resulting yogurt was 87.04 points, which was very close to the theoretically predicted value of 87.32 points. Analysis of the quality indicators of this yogurt revealed the following: Protein content of 3.4 g/100 g, fat content of 2.7 g/100 g, non-fat milk solids of 9.1 g/100 g, acidity of 65.5°T, lactic acid bacteria count of 1.9×10⁸ CFU/g, mold count<1.0 CFU/g, and no pathogenic bacteria were detected. The quality meets all the requirements specified in GB 19302—2025 National food safety standard for fermented milk.

This study optimize a composite-flavored yogurt that combines the aromas of sweet potato and fruit, providing feasible process parameters and data support for the industrial production of multi-flavored fermented milk. It holds significant importance for the deep processing of specialty fruit and vegetable raw materials and the expansion of the industrial chain.