Characteristics and release of monosodium glutamate microcapsules obtained by spray drying

Abstract

The present study aimed at investigating the characteristics of monosodium glutamate (MSG) microcapsules. Spray-drying was used to prepare the microcapsules, in which the core material (MSG) was coated with gum Arabic (GA) and maltodextrin (MD), and the weight ratio of MD with GA was 1:2. The characteristics of microcapsules were evaluated by scanning electron microscopy (SEM), moisture content, particle size, Fourier-transform infrared (FTIR), differential scanning calorimeter (DSC), thermogravimetry analysis (TGA), release behavior, the flavor, and taste in hot-pot. Few concave wrinkles were observed on the quasispheres surface of microcapsules coated with GA and MD. The particle size of the microcapsules ranged from 14.00 to 30.00 µm in the mean diameter, and moisture content was 2.08%. An FTIR study indicated a successful packet of MSG by wall materials and the formation of MSG microcapsules during spray drying. Results of DSC and TGA showed that hybrid encapsulation was conducive to the improvement of thermal stability of MSG. In the release of hot-pot study, tests of slow-release, electronic nose, and electronic tongue demonstrated that MSG microcapsules were available in hot water conditions to release. The MSG microcapsules coated with GA and MD exhibited long time for slow-release. Therefore, spraying drying is a suitable approach to manufacture slow-released powdered microcapsules.