Increasing energy efficiency in microencapsulation of soybean oil by spray drying

Abstract

The aim of this study was to evaluate the influence of inlet air temperature of spray drying on microparticles properties and heat loss on drying chamber in sense to select the conditions that promote the preservation of functional compounds and improve energy efficiency. The energy efficiency of the process was evaluated varying inlet air temperature (T) from 110 to 150 °C and airflow (AF) from 20 to 40kg/h, being the energy efficiency, the response variable. The microspheres presented a continuous surface and no cracking, which hinders the diffusion of air and reduces the probability of triglycerides oxidation in the nucleus. The heat loss curves were plotted considering the principles of mass and energy conservation applied to both input and output currents. Further, the thermodynamic parameters were continuously monitored during the spray dryer. So, the selected operational conditions (T = 130 °C, AF = 20 kg.h 1 ) allowed to achieve high encapsulation efficiency (95%) and saving energy compared to conventional processes using inlet air temperatures above 180 °C, a significant improvement to thermo-sensitive compounds.