Abstract: Spray drying(SD) is used to investigate the dehydration of Opuntia Milpa Alta. Inlet air temperature in spray drying is usually a significant factor for final product property. Different inlet air temperatures, i.e., 90, 140, 190 and 240℃, are selected in this study. The properties of dried cactus powder, i.e., residual moisture, particle size distribution, SEM, vitamin C, flavone, and color difference, are presented. The results showed that all residual moisture in product by SD was less than 6%. SEM of the dried product showed that the particles were round with some shrinkage hole and some were maintained in strip due to initial mill process. Most mean particle sizes were changed from 8.6 μm to 24.3 μm. It was also seen that the measured vitamin C in dried products and color difference decreased while the inlet air temperature increased. Maximum vitamin C content at 1 776 μg/g was obtained when inlet air temperature 90℃ was used in spray drying. The flavone content of cactus powder was decreased while the inlet air temperature increased. Maximum flavone content of cactus powder was 2.28 mg/g at inlet air temperature 90℃.

Key words: edible cactus, spray drying, SEM, vitamin C, flavone