Optimization of spray drying parameters for beetroot juice powder using response surface methodology (RSM)

AbstractThe optimization of beetroot juice powder was devised using Box-Behnken design to optimize the spray drying parameters of inlet air temperature (IAT) (160–180°C), maltodextrin (MD) addition rate (5–15%) and feed flow rate (FFR) (400–600ml/h). The experimental results were (p<0.05) fitted into the second-order polynomial model to describe and predict the response in terms of the powder yield, hygroscopicity, redness value, betalain retention (BR %) and radical scavenging activity (RSA %). The powder yield significantly (p<0.01) increased with increasing inlet temperature, whereas the redness value, BR, and RSA decreased. With the increasing rate of MD addition, redness value, BR, and RSA increased. The hygroscopicity values decreased with increasing feed flow rate. The effect of feed flow rate on the rest of responses was found non-significant at a level of p>0.05 except hygroscopicity. The optimum conditions were found as 160°C inlet air temperature and 400ml/h feed flow rate and a maltodextrin concentration of 15% with using desirability function