El-Guendouz, S., Aazza, S., Dandlen, S.A., Majdoub, N., Lyoussi, B., Raposo, S., Gomes, V., Bankova, V., Popova, M.,
Antunes, D., Miguel, M.G.
This study compared the capacity of propolisextract (PE) and thyme waste extract (TWE) to prevent theoxidation of oil in water (O/W) emulsion, as well as theirimpact on emulsion apparent viscosity (AV) in the presenceof wheat germ and almond oils as lipid phase. For this,central composite design (CCD) and principal componentanalysis (PCA) were performed. Oxidation process wasmonitored by evaluating the formation of primary and sec-ondary lipid oxidation products, at the same time the AVbehavior was determined evaluating consistency index andflow behavior index. The results revealed that the increase of PE% and TWE% decreases TBARS (Thiobarbituric AcidReactive Substances) and hydroperoxides formation. Vis-cosity increases with the rise of TWE% over (0.04%),whereas lower concentrations of PE% decreases it. Thoseresults have been confirmed in the PCA analysis. TWEshowed higher resistance to oxidation, although PE wasmore effective as antioxidant than TWE.
