Use of propolis extracts as antioxidant in dairy beverages enriched with conjugated linoleic acid

The addition of propolis to food formulations containing conjugated linoleic acid (CLA) can improve nutritional properties and stability during storage. The purpose of this study was to enrich dairy beverages with both CLA and Canadian propolis extracts and to determine the chemical characteristics of the enriched beverages, with a focus on antioxidant properties and protection against lipid oxidation. Analysis of DPPH, ORAC, color and aldehyde production along with CLA quantification was performed. Adding different propolis extracts increased the antioxidant capacity of dairy beverages enriched with CLA, while pasteurization treatment reduced the antioxidant capacity. The production of aldehydes during storage under light exposure was reduced significantly in the presence of propolis extracts. Since no nutritional loss was observed during processing and storage of dairy beverages, the main advantage of using propolis extract relates to its higher antioxidant capacity and ability to reduce off-flavors associated with aldehyde production.