study of drying method types on the physicochemical characteristics of purple-fleshed sweet potato extract powder

The purpose of this study was to obtain the best anthocyanin pigment extract powder from 3 types of drying process, vacuum drying, spray drying, and freeze-drying. the duration and temperature for each type of drying process are 15 h with temperature of 40 °c, 2 h with temperature of 120 °c (inlet) and 60 °c (outlet), 24 h with temperature of -50 oc respectively. this research used the randomized block design method consisting of three treatments with four replications. if there is a significant difference between treatments, the test is continued with the duncan test. three drying methods, namely: treatment a = vacuum drying, treatment b = spray drying, treatment c = freeze-drying. the freeze-drying method produces the best characteristics with total anthocyanin 121.63 mg/100 g (db), color intensity l* (brightness) 64.20, a* (redness) 65.60, b* (yellowness) 18, 52, water content 5.00%, hygroscopicity 12.87%, solubility 97.21%, dissolution time 151 seconds, ph level 2.93, yield 28.69%, and psa 0.95 μm. based on the experiment’s result, freeze-drying method was the most suitable parameter for physiochemistry characteristic. it has the highest amount of anthocyanin, the highest antioxidant activity, and the smallest amount of psa (particle size analyzer).