Characterization and comparison of UK, Irish, and French cold pressed rapeseed oils with refined rapeseed oils and extra virgin olive oils

Various chemical parameters were used to characterize a wide range of cold pressed rapeseed oils and to contrast the findings with refined rapeseed and extra virgin olive oil. There were significant differences between cold pressed rapeseed oils regarding almost all measured parameters. Volatile composition analysis showed that hexanal, 3-methyl pentane and 1-butene, 4-isothiocyanato were the most abundant compounds. There was no correlation between volatile compounds and geographical region of cold pressed rapeseed oils. French cold pressed rapeseed oils were found in exhibit significantly higher antioxidant activity levels than cold pressed rapeseed oils from other regions. Refined rapeseed oil was found to have a higher antioxidant activity but have significantly lower levels of phenolic acids (0.008 mg/kg oil) than cold pressed rapeseed oil (0.46 mg/kg oil). These phenolic acids appear to be important for oxidative stability as cold pressed rapeseed oil was more stable under heat stress than refined rapeseed oil. Olive oil was the most stable under heat stress, largely due to its comparatively high saturated fat content. Antioxidant potential, phenolic acids and peroxide values were found to be the main factors differentiating cold pressed rapeseed oil from refined rapeseed oil. Practical applications: Cold pressed rapeseed oil is a relatively new oil to the market and this study is the first to examine oils available to the British, Irish and French consumers. It shows the compositional variation of oils on the market by analyzing many parameters important for oil quality and consumer palatability. Antioxidant behavior and phenolic acid identification indicate potential health benefiting properties. This research also compares cold pressed rapeseed oils with market competitors which allows for clear comparison of these widely used edible oils. Cold pressed rapeseed oil is made by mechanically crushing rapeseeds at a low temperature, followed by filtering and bottling the oil. This work investigates the chemical composition of cold pressed rapeseed oil, along with its antioxidant capacity and stability under heat stress. Cold pressed rapeseed oil is also compared to market competitors; refined rapeseed oil and extra virgin olive oil.