Effect Coriandrum sativum L. Extracts on the Oxidative Stability of Cold-Pressed Sunflower Oil

One of the most important quality parameters of edible vegetable oils is their oxidation stability, especially when their chemical composition is dominated by polyunsaturated fatty acids, which are susceptible to oxidation. Even under optimal storage conditions, these oils have a limited shelf life. Given the harmful effects of synthetic antioxidants, increasing attention has been directed towards natural antioxidants in efforts to delay oxidative changes in edible oils. Medicinal and aromatic plants are used worldwide as food ingredients, flavouring agents and sources of promising antioxidants. In this context, the main objective of this study was to evaluate the effect of ethanolic extracts obtained from coriander seeds on the oxidative stability of cold-pressed sunflower oil (CPSO). The preliminary tests focused on evaluating the influence of the extraction conditions (extraction technique and solvent type) on the antioxidant activity of the coriander extracts. Regardless of the extraction technique employed, 70% ethanolic extracts showed a stronger antioxidant effect compared to 96% extracts, which is why 70% ethanolic extracts were selected for further analyses. These extracts were added to fresh CPSO at different concentrations (250, 500 and 1000 ppm) and their stabilising effects were monitored using accelerated techniques (Schaal oven and Rancimat test). While the lower concentrations of coriander extract showed certain capacity to delay oxidative changes, the highest concentration acted as a pro-oxidant.