Effects of blanching and drying on fiber rich powder from pitaya (Hylocereus undatus) peel

The pitaya (Hylocereus undatus (Haw.)), a member of the Cactaceae, with white-flesh is a one of the famous varieties in Thailand and shows antioxidant activity from its pigment. However, its peels was handled as a waste, therefore the applying these materials could be get more benefits in producing fiber rich powder. The effects of blanching in hot water and drying at various temperatures (60°C, 70°C and 80°C) were investigated. The result showed that the blanched pitaya peel showed lower amounts of anthocyanin and betacyanin contents. Moreover, thermal degradation of anthocyanin and betacyanin could be occurred during drying process. However, the higher drying temperature trends to increase the antiradical activity of dried sample. This information provided that the pitaya peels is a valuable material for a manufacture of fiber-rich powder with high antiradical activity.