Effect of drying methods and storage conditions on quality of purple sweet potato leaves

Purple sweet potato has been gradually increasing in terms of planting and consumption, but after harvesting the leaves of the sweet potato are often discarded as waste or used for animal feed. The aim of this study was to determine the effect of drying methods on the quality of sweet potato leaf powder and its storage capacity. The nutritional and antioxidant properties of powder were analyzed. The results showed that hot air drying could preserve antioxidant properties than the sun drying method. Both methods could produce a product with high nutritional value, especially a high amount of protein and fiber. It could be considered a supplementation ingredient for the food industry. Moreover, after storage at room temperature for 12 weeks, a slight increase in moisture content and decreased of antioxidant properties was found. Further, the application of this ingredient should be investigated more in food application to improve the income for local farmers as well as reduce the waste that harms to environment.