Evaluation of spray drying conditions on properties of microencapsulated oregano essential oil

• Main Author: Botrel, D. A.
• Publication Date: 2012
• Other Authors: Borges, Soraia Vilela, Fernandes, R. V. de B., Viana, A. D., Costa, J. M. G. da, Marques, G. R.
• Format: Article
• Language: eng
• Source: Repositório Institucional da UFLA
• Download full: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.2012.03100.x/abstract; http://repositorio.ufla.br/jspui/handle/1/4711
• topic: Essential oils; Microencapsulation; Physicochemical properties; Response surface methodology; Spray drying; Starch

Response surface methodology (RSM) was employed to investigate variations in powder characteristics with respect to spray drying operating parameters including both feed rates (L min )1 ) and inlet temperatures (°C). Inlet temperatures around 180 °C provided the lowest values for moisture. Powder recovery was significantly affected (P < 0.10) by inlet air temperature and feed rate, where a raise in inlet temperature and feed rate resulted in higher powder recovery. No significant difference (P > 0.05) was observed for water activity, solubility and hygroscopicity between treatments. Regarding oil retention, the results showed a significant (P < 0.05) interaction between the two studied factors. A tendency for higher values of oil retention was observed when using combinations of high inlet temperatures ⁄ low feed rates and low inlet temperatures ⁄ high feed rates. Particle size distribution averaged 2.0, 8.1 and 18.3 lm for D 10 , D 50 and D 90 , respectively. The morphology of particles showed no cracks in most capsules. The results indicate that high temperature (185 °C) and moderated feed rate (0.63 L min )1 ) are the best spray drying conditions.