A factorial design was performed for the microencapsulation of chia oil by spray drying at pilot-scale, to validate the results obtained previously at laboratory scale in a Buchi-B290. The effects of drying-air inlet (T-inlet) and outlet (T-outlet) temperatures in a Niro Production Minor on the solid yield, thermal efficiency, theoretical droplet evaporation times, and physico-chemical properties of powders were analyzed. The theoretical droplet evaporation times (0.31-0.54 s) were calculated considering the constant and falling rate periods and a negligible relative velocity between spray and air. Critical diameters between 31.77-41.57 mu m were estimated for microcapsules, depending on the process conditions. After scaleup of the spray drying operation, higher solid yields (74.24-79.79%), thermal efficiencies (27.56-73.19%), encapsulation efficiencies (96.97-98.57%), and enhanced flowability of products, compared with experiments at laboratory scale, were observed. Moreover, the scale-up did not affect the chemical composition of microencapsulated oils, their fatty acid composition before and after in-vitro digestion processes. A global optimization was performed at pilot-scale and the process conditions that simultaneously optimized all the responses was 160 degrees C x 90 degrees C (T-inlet x T-outlet). (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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