Encapsulations of wild garlic (Allium ursinum L.) extract using spray congealing technology

The objective of this study was to incorporate wild garlic (A. ursinum) extract into microparticles (MPs) in order to protect its valuable active compounds and improve its oral bioavailability. For this purpose, spray congealing technology was applied and Gelucire 50/13 (Stearoyl polyoxyl-32 glycerides) was selected as MPs carrier. MPs were characterized in terms of yield, encapsulation efficiency and particle size. Differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FT-IR) analysis of MPs showed the absence of chemical interactions between carrier and extract and suggested that spray congealing process did not modify nor degrade the encapsulated extract. The encapsulation into MPs led to an improvement of the extract dissolution performance as well as an enhancement in solubility of >18 fold compared to the pure extract. Additionally, MPs were stable over three months showing only a minor decrease in the content of active compounds (allicin and S-methyl methanethiosulfonate) and maintaining a good antimicrobial activity. Therefore, obtained results suggested that the encapsulation of A. ursinum extract in MPs by spray congealing is a promising approach to improve the biopharmaceutical properties of the extract, without affecting its antibacterial activity.