Influence of spray‐dryer air temperatures on encapsulated lime essential oil

Abstract

SummaryThe influence of inlet and outlet air temperatures (180–220 and 80–100 °C, respectively) on the spray drying of lime essential oil was evaluated by using a three‐level factor design. For optimisation, dryer evaporative rate, volatile oil retention, and microencapsulation efficiency were considered as response variables. The response surface analysis produced significant (P < 0.05) polynomial regression equations that were successfully fitted for all response variables, and no significant (P > 0.05) lack of fit was indicated for the reduced models, with the exception of microencapsulation efficiency. This observation confirmed an accurate fitness of the reduced response surface models to the experimental data. The multiple response optimisations indicated that an inlet air temperature of 220 °C and an outlet air temperature of 85 °C were predicted to provide the maximum evaporative rate (7.7 kg h−1), volatile oil retention (95.7%), and microencapsulation efficiency (99.9%) in the studied ranges. Checking of the optimisation showed that with these optimal parameters, a very good closeness between the experimental and predicted values was obtained.