Abstract:In this paper, the effects of different hot air drying temperatures (40, 60, 80, 100, 120 ℃) on drying kinetics, color, water activity, polyphenol content and antioxidant capacity (DPPH, FRAP) of ice plant were studied with freeze-drying considered as the control treatment. The results showed that the drying time for ice plant was shorter as the temperature increase. SLogistic1 model equation was found as the best fit at various temperatures, and the correlation coefficient (R2) was highest (>0.970). The total phenols, total flavonoids and antioxidant activities in ice plant increased with the increase of drying temperature (40-80 ℃). However, total phenols, total flavonoids and antioxidant activities decreased when the temperature higher than 80 ℃. And the DPPH and FRAP values of ice plant dried by 80 ℃ hot air were 24.3 mg TE/g dw and 105.0 mg TE/g dw, respectively. Furthermore, the content of protocatechuic acid, chlorogenic acid, caffeic acid, cumaric acid and ferulic acid in ice plant dried at 80 ℃ were significantly higher than those of other hot air drying temperature. On the other hand, ice plant dried by 80 ℃ hot air showed the lowest color differences compared with their freeze-dried counterpart. As a result, hot air-drying at 80 ℃ was a recommended drying method for ice plant.