Optimization of Spray Drying Parameters for Yogurt-Ice Cream Mix

摘要

The effects of spray drying operating variables such as inlet air temperature, pump speed and feed temperature on final moisture content, particle size and bulk density of yoghurt-ice cream mix powder, and the powder recovery and the drying rate of the drying process were evaluated. Final moisture content decreased with an increase in inlet air temperature and a decrease in pump speed while particle size increased with an increase in both inlet air temperature and pump speed. Bulk density was inversely proportional to particle size. Drying rate increased with an increase in pump speed and feed temperature. Powder recovery increased with an increase in inlet air temperature and feed temperature and a decrease in pump speed. All response models generated through response surface methodology were adequate, having R2 values higher than 0.60 and a coefficient of variation below 10%. The optimum spray drying conditions found for yoghurt-ice cream mix were: inlet air temperature of 180 °C, pump speed of12 x 103 rpm, feed temperature of 43 °C and air pressure of 1-2 bars.