In this research, spray drying process was used to produce malt extract powder. The effect of two parameters including inlet air temperature at three levels (160, 170 and 180°C) and maltodextrin concentration at levels 0, 10, 20 and 30% on powder properties were investigated. The properties of malt extract powder including particle size, theoretical specific surface area, particle size distribution and span value, scorched particles and solubility index, vitamin B2 content, glass transition and sticky point temperature were measured. Results indicated that spray drying method could dry malt extract with high quality. The drying efficiency depended on inlet air temperature and maltodextrin concentration. Increasing inlet air temperature and maltodextrin concentration would enhance drying performance. At spray drying conditions including 170°C and 20% maltodextrin the highest quality (disk B for the scorched particle grade and the solubility amount equal to 0.05 ml) and powder uniformity (average particle size of 22 microns) was obtained. At this condition, vitamin B2 content was 1.56 mg/100g product).
Department of Food Science & Technology, Quchan Branch, Islamic Azad University, Quchan, Iran.