Preparation and characterization of allyl isothiocyanate microcapsules by spray drying

The objective of this study was to establish the ability of microencapsulation to entrap allyl isothiocyanate (AITC) and extend its shelf life. Microcapsules were prepared by spray drying after emulsification, using different mass ratios of gum arabic (GA) to AITC (3:1, 4:1, 5:1 and 6:1) with tween20 or span80. The microencapsulation efficiency and release characteristics of GA/AITC microcapsules were investigated. Retention of AITC during spray drying was increased as the mass ratio of GA to AITC increased. The Avarami's parameter n values of all AITC powders indicated that release of AITC was controlled by diffusion through the wall of the particles. The release rate of AITC was not only dependent on the emulsifier type, but also on the mass ratio of GA to AITC. The highest retention of AITC was achieved at a GA:AITC mass ratio of 4:1 in 0.7% tween20.