Applying Iranian Gum Tragacanth to Improve Textural Properties of Maltodextrin Microcapsules

The effects of adding one of the species of Iranian gum tragacanth, Astragalus compactus, to maltodextrin solutions used for microencapsulation of 2-methylbutyl acetate (water-soluble flavoring compound of strawberry) were studied. Initial emulsions were evaluated regarding rheological behavior and particle size distribution. The resulted microcapsules were also analyzed for particle size distributions, glass transition temperature T_g , the morphology of the capsules and the rate of release from them. The results showed that addition of 0.5% w/w A. compactus gum to maltodextrin solutions (14.5% w/w) can increase the viscosity and T_g to an optimum level and can prevent stickiness. Also this species of gum tragacanth had an interesting effect in reducing physical defects of microcapsules and eliminated ruptures significantly. It was also showed that the rate of release of 2-methylbutyl acetate decreased by incorporating gum tragacanth in the wall material. PRACTICAL APPLICATIONS: Microencapsulation is of great interest in preservation of flavoring compounds. One of the most important wall materials is maltodextrin, which has several defects to protect flavorings. This study proposes the use of a new material, Iranian gum tragacanth from Astragalus compactus, to overcome these defects. It was found that new microcapsules did not undergo rupture and could retain the flavoring well.