건조 방법에 따른 유색고구마 분말의 색 안정성과 항산화 활성

Purpose: To determine good drying methods for making pigmented sweet potato (SP) powders, three different SP cultivars (purple fleshed Danjami, cream fleshed Jinyulmi, and orange fleshed Hogammi) were dried by freeze-drying (FD), natural drying (ND), and low temperature drying using a 40℃ oven (LD). Methods: The physical properties, color stabilities during storage, and antioxidant activities of the three SP powders produced by applying the three different drying methods were investigated. Results: The physical properties and color values differed significantly using different cultivars and drying methods (p<0.05). Moisture content and swelling power were found to be the lowest in the FD powder and ND powder, respectively whereas the highest water binding capacity was found in the LD powder. Regardless of the cultivars used, ND powder had the highest color stability at the end of 30 days storage. Danjami SP powder was the most stable after 30 day storage; FD powder of Jinyulmi SP was stable for only 5 days, but the LD powder retained stability for 30 days. The Hogammi FD powder was found to be the most unstable. Natural drying was determined to be the best method for making SP powder, regardless of the cultivars. The antioxidant activities of all three cultivars were similar, with Danjami powder having maximum activity. Conclusion: Taken together, our results indicate that SP powder using natural drying has the most desirable antioxidant activity and color stability, which differs from the natural pigment present in sweet potato.