Effect of spray drying conditions on the physical properties of Cagaita (Eugenia dysenterica DC.) fruit extracts

Cagaita is a Brazilian native fruit with potential health effects associated with its high content and peculiar profile of polyphenols. The aim of this work was to produce spray dried extracts from Eugenia dysenterica fruit comparing gum arabic (GA) and inulin as carrier agents and to evaluate the effect of different drying conditions on the physical properties of the resulting powders. The inlet air temperature (120 degrees C, 140 degrees C and 160 degrees C) and concentrations of carrier agents (10%, 20% and 30%) were tested. Samples were evaluated for moisture content, water activity, hygroscopicity, solubility, glass transition temperature, color and particle morphology, and results were subjected to response surface methodology. A freezedried sample was used for comparison. A better yield was observed when using GA as carrier agent. Regarding the moisture content and water activity of the powders, all samples showed better values than those presented by the freeze-dried sample. The spray drying process increased the solubility and reduced the hygroscopicity of the samples. The glass transition temperature was more affected by temperature in case of samples with GA; in contrast, the concentration of carrier agent was the parameter that most influenced the samples spray-dried with inulin. The morphology of the particles was affected by both the carrier concentration and temperature. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.