Background: Fruit yogurt often undergoes physical and chemical deterioration due to the instability of its texture. Adding natural-based stabilizers, such as fermented sweet potato flour, was investigated as a potential approach for yogurt stabilization. Objectives: This study aimed to evaluate the effect of adding different concentrations (0%, 0.5%,1%, 1.5%, 2%, and 2.5% w/w) of fermented sweet potato flour on the physicochemical and sensory properties of salak pondoh fruit yogurt and to determine their best treatment during storage. Methods: Yogurt samples were prepared with varying concentrations of fermented sweet potato flour and analyzed for physicochemical properties, including pH, acidity, water-holding capacity, total soluble solids, viscosity, and syneresis. The growth of lactic acid bacteria was also evaluated. Sensory analysis was conducted to assess overall acceptability. The samples were stored and evaluated over 21 days at 5oC. Results: Significant differences were observed in the physicochemical properties of yogurt supplemented with fermented sweet potato flour. Improvements in viscosity and water-holding capacity and reductions in syneresis were noted with increasing concentrations. Likewise, the growth of lactic acid bacteria increased with higher levels of supplementation. Fermented sweet potato flour at 2.5% resulted in the lowest syneresis without affecting physicochemical properties or overall acceptability. Additionally, yogurt supplemented with 2.5% flour maintained good quality during 21 days of storage. Conclusion: Fermented sweet potato flour at 2.5% can be used as an effective natural stabilizer in salak pondoh fruit yogurt, improving its quality and storage stability.
Yuliana et al. (Wed,) studied this question.