Chitosan microparticles with different concentrations of thyme essential oil
In this study, thyme essential oil has been encapsulated in chitosan microparticles by the oil-in-water (o/w) emulsion cross-linking method. The effects of initial thyme essential oil concentration in the range from 0.3 to 1.5 vol.% on thyme essential oil loading and encapsulation efficiency were first investigated. The results are presented in Fig. 4.
The increase of the initial thyme concentration affected significantly its loading. Thyme essential oil loading increased rapidly with increasing concentration of thyme oil in the initial solution and then reached a maximum value of 58.85±1.32 mg/100 mg of micropar- ticles. It seemed that the maximum loading for chitosan microparticles was not reached in this experiment. The encapsulation efficiency appeared to slightly increase with the thyme concentration, being in the range from 77.89±4.0 to 85.56±7.19%, for thyme concentration of 0.3 and 1.5 vol.%, respectively. This result is in accord- ance with previous published data