Does crude oil extraction technique affect canola oil functionality?

Crude oil extraction technique can affect the physicochemical properties of canola oil. However, the effect on refined canola oil is not well studied. This study investigated the frying characteristics of two refined canola oils obtained by two extraction techniques – mechanical-pressing (MCO) and solvent-extraction (SCO). Refined canola oils from both extraction techniques were obtained from Australian processors and used to fry potato chips. Differences in frying functionality of the oils were assessed by monitoring oil degradation indices total polar materials, tocopherols degradation and changes in the major fatty acids oleic, linoleic and linolenic acids. The refined canola oil from mechanical-pressing exhibited better frying stability than the refined oil from solvent-extraction. The frying life was correlated with tocopherols degradation during frying with greater tocopherols loss correlating with reduced frying life. The differences in canola oil frying performance most likely resulted from differences in crude oils obtained by the two extraction techniques which effected changes in the refined canola oils. Also, process variations as applied by the different processors can affect refined oil quality, hence canola oil functionality. The result of this study could serve as a platform for optimisation of existing processes to produce canola oils with better functionalities.