Rosemary powder filtrate improves the oxidative stability and antioxidant properties of rapeseed oil: potential applications for domestic cooking

Rapeseed oil is an important source of edible oil for the human diet but is also highly susceptible to oxidative deterioration. Previous research has demonstrated that rosemary powder and its extracts can increase the oxidative stability of rapeseed oil. In this study, the protective effect of ground rosemary powder (0.25-2.0%) against the oxidative degradation of filtered rapeseed oil was assessed. Rapeseed oil filtrate showed enhanced antioxidant capacity and higher induction periods (IP) based on Rancimat analysis. Lower conductivity changes and total colour differences, reduced malondialdehyde and conjugated dienes content, and higher levels of tocopherols and carotenoids were observed for the oils formulated with rosemary powder after 1.5 and 3 h of exposure to accelerated oxidation. The use of rosemary powder filtrate could be an effective way to protect rapeseed oil from oxidation during storage or cooking with domestic and commercial applications.