Abstract
Karanda fruits are widely cultivated in Thailand. The fruit has several vitamins and minerals. One of the most fascinating possibilities is to transform it into a powdered drink. This study aimed to determine the optimal conditions for preparing karanda juice powder considering its physicochemical properties. Three levels of inlet air temperature were evaluated, 160 oC, 180 oC and 200 oC. Subsequently, three levels of maltodextrin (dextrose equivalent 10, DE10) were evaluated, 30%, 40%, and 50% by weight. Finally, three levels of whey protein (WPI) were evaluated, 5%, 10%, and 15% by weight. The moisture content dropped by 48.51% when the input air drying temperature rose from 160-200 °C. Yield increased by 15.08% and solubility by 5.06%. The maltodextrin content was increased from 30% to 50%, resulting in a 23.17% increase in product yield, while the WPI content was increased from 5% to 15%, leading in an 82.88% increase in anthocyanin content. SEM investigation indicated that the particle morphology was spherical with smooth surfaces, but an increase in inlet air temperature led to greater deformation and particle surface roughness. Additionally, the optimal parameters for spray drying karanda fruit were an inlet air temperature of 174 °C, maltodextrin (MD) content of 32%, and WPI content of 15% of soluble solids, with a product yield of 55.93±0.25%, solubility of 85.51±0.54%, and anthocyanin concentration of 12.58±0.36 mg/l.
