Effect of Lyophilised Sweet Potato on the Quality and Nutritional Characteristics of Set Yogurt

This study examined the functional properties of yogurts produced from two distinct lyophilized dried sweet potatoes and analyzed the temporal changes in those properties during storage. Adding purple and orange sweet potatoes had different effects on the changes in the quality, nutritional, microbiological, and functional properties of yogurt. These effects generally increased in parallel with the added amounts. At the end of storage, it was determined that the samples with 2% purple sweet potato added had the highest dry matter (8.45%), water holding capacity (50.90), DPPH radical scavenging effect (112.97%), and total phenolic substance (2.64 mg GAE/g) values. It was also determined that the richest samples in terms of mineral content were yogurts produced with the addition of 2% purple sweet potato, and the highest minerals were potassium (2,765,987.42 ppb), sodium (250,078 ppb), and magnesium (203,691.47 ppb), respectively. Similarly, it was determined that the textural properties were better in yogurt samples produced with a 2% purple sweet potato addition (the highest firmness (229.07 g) consistency (2690.00 g) cohesiveness (−81.70) and viscosity index (−290.54 g)). On the other hand, the highest oxalic (6.021 mg/kg), tartaric (26.068 mg/kg), formic (10,860 mg/kg), malic (196.11 mg/kg), ascorbic (10.75 mg/kg), and lactic acid (2762.83 mg/kg) values on the last day of storage were found in yogurts produced with a 2% orange sweet potato addition.