Background and Aim: Food safety is an important aspect to be evaluated in preventing any potentially harmful side effects of food product such as yogurt. The purple sweet potato yogurt product was developed to combine the benefits of probiotic activities in yogurt and the bioactive effects of anthocyanin in purple sweet potato. This study was performed to investigate acute and sub-chronic oral toxicity of purple sweet potato yogurt (PSPY) in mice.

Materials and Methods: Acute oral toxicity was evaluated by a 14-day observation for any clinical sign of toxicity on fifteen female balb/c mice following a single dosage of PSPY (nil, 2 or 5 g/kg body weight). The sub-chronic oral toxicity study was conducted by feeding PSPY to four groups of mice with the dose of 0, 12, 20, and 40 g/kg body weight for 28 days, and another group of mice receiving 40 g/kg body weight purple sweet potato for 14 days longer to observe any delayed toxicity effect. Body weight and clinical signs of toxicity were observed daily. Liver and kidney macroscopy and relative organ weight, liver histology, liver enzyme, and hematology profile analyses were done at the end of the study.

Results: There were no signs of toxicity observed from the acute toxicity study and no abnormality in body weight, relative organ weight, and gross organ examination. In the sub-chronic toxicity study, there were no clinical signs of toxicity, no significant differences in body weight, relative liver weight, liver enzymes, hematology profile, or abnormality in gross and histological examination of the liver.

Conclusion: This study shows that oral administration of PSPY in mice up to 5 g/kg body weight did not result in acute toxicity, while the dosage up to 40 g/kg body weight did not lead to sub-chronic toxicity.

Keywords: acute oral toxicity, anthocyanin, purple sweet potato, sub-chronic oral toxicity, yogurt.