Effect of spray drying temperature on quality of longan beverage powder

Abstract

This research was aimed to investigate the effect of spray drying temperature on quality of longan beverage powder and find a suitable drying condition. Production of longan beverage powder used 3 drying aids, namely maltodextrin, modified starch and gum arabic at the ratio of 85:10:5. The mixed drying aid was added to longan juice at 0.6 g/g soluble solids. The juice was subsequently spray dried using inlet air temperature of 165, 175 and 185°C and outlet air temperature of 75±2°C. The results showed that the optimum inlet temperature was 185°C, saving the highest % yield of 78.86±0.64, lowest moisture content and water activity of 4.04±0.03% and 0.258±0.02, respectively, lower angle of repose of 39.13±0.33°, the highest solubility, glass transition temperature and overall thermal efficiency were 91.95±0.11%, 58.81±0.32°C and 68.75±0.73%, respectively. Sensorial preference of color, odor, taste, dissolution and overall liking were not significantly different (p>0.05) when compared with the sample dried at 165 and 175°C.