Impact of temperature and relative humidity on physicochemical properties of the spray dried red flesh pitaya powder during storage

This study was carried out to evaluate the changes in physicochemical properties of pitaya powder produced by spray-drying under the different temperature storage at 5-7 , room temperature, and 50 for 40 days, The results showed that delta E of color increased but the content of betacyanin and total phenolic decreased following temperature increase. The degradation of betacyanin and total phenolic content in all samples during storage fitted the first-order reaction. Moreover, the behavior of moisture content in pitaya powder under different relative humidity was investigated. The isotherm curve of pitaya powder was built (y = 3,2655e0,0106x). The result also showed the GAB equation can be used to calculate the M0 of the sample better than the BET equation.