Optimization of the spray drying process for developing cupuassu powder.

A central composite design was used to optimize the spray drying process for developing cupuassu (Theobroma grandiflorum) powder. The influence of inlet air temperature (Tinlet) (120-180 °C), feeding rate (Ffeed) (3-12 mL/min) and maltodextrin concentration (Cmalto) (10-40%) on the properties of moisture, water activity (aw), hygroscopicity, water solubility index (WSI), ascorbic acid (AA) and total phenolic compounds (TPC) were analyzed using response surface methodology and desirability function. In addition, powder morphology was assessed using scanning electron microscopy. The Tinlet and Ffeed parameters significantly influenced the moisture and aw, while the other responses (hygroscopicity, WSI, AA and TPC) were influenced by the Tinlet and Cmalto parameters. The highest Cmalto and intermediate Tinlet and Ffeed levels showed the best morphological characteristics (particles integrity, spheres shapes and smooth surfaces). The desirability function defined the optimal process conditions as Tinlet = 150 °C, Ffeed = 7.5 mL/min and Cmalto = 40%.