Effect of freeze‐drying on the antioxidant and the cytotoxic properties of Allium roseum L. and its application in stabilizing food emulsions

Abstract

Allium roseum is a wild edible plant in North Africa. In the present study, the effect of freeze‐drying on the phenolic profile, the antioxidant and the cytotoxic properties of this plant is investigated for the first time. Furthermore, this is the first research that studies its ability to preserve the stability of emulsions. We found that water extract prepared from freeze‐dried leaves (FDL) contains higher amount of phenolic compounds than the extract prepared from fresh leaves (FL) and therefore the most important antioxidant power. FDL extract is more cytotoxic on K562, MCF‐7 and Caco‐2 cancer cells. Chromatographic analyses identified kæmpferol and luteolin‐7‐o‐glucoside as the major phenolic compounds. Finally, water extract prepared from FDL preserved the physical stability of W/O emulsion at 4 °C and room temperature over 30 days. It also protects those emulsions from the production of free radicals at the same temperatures and during the whole storage period.