Efeito da temperatura do ar de secagem e dos agentes encapsulantes no microencapsulamento de óleo de laranja em leito de jorro e em secador por atomização

Abstract

In this research the orange essential oil encapsulation process in spouted bed dryers and spray dryers was evaluated. The effects of temperature variations and different encapsulating agents in microcapsules formation were also determined. The experiments were carried out at 40, 60 and 80 C, when the spouted bed dryer was used, and at 190 C, when the process was performed in the spray dryer. The encapsulating emulsion composition consisted of 10 % (w/w) of essential orange oil, 46 % (w/w) of encapsulating agent and 44 % (w/w) of water. The encapsulating agents evaluated were prepared blending malt dextrin (20DE), Capsul® and gum arabic. The microscopic analysis of the microcapsules obtained in the spouted bed dryer show that both, the temperature and the encapsulating emulsion composition, affect the orange essential oil retention rate. It was also observed that the encapsulating agent composition affects the microcapsules formation and orange essential oil retention rate, when the process was carried out in the spray dryer. The results obtained allowed to conclude that the encapsulating blends containing Capsul® reached better performance in temperatures above 60 oC, in both equipments. The analysis of the microcapsules microscopic pictures show that the product obtained in the spouted bed dryer is morphologically different from that obtained in the spray dryer. The differences observed could be attributed to temperature and encapsulating blend composition variations. It was possible to verify that the equipment applied in encapsulation process also affected the microcapsules morphological properties.