This study investigated variability in the frying life of refined canola oil obtained by different crude oil processing practices. Refined canola oil samples were drawn from the 2016/2017 and 2017/2018 production seasons and included two expeller-pressed (ExCanO-1 and ExCanO-2) and two solvent/expeller blended (BlCanO-1 and BlCanO-2) canola oils. Oil samples were used to fry potato chips 36 to 48 times, and the total polar compounds, tocopherol content, anisidine value and antioxidative capacity were measured as indices of frying life. The expeller-pressed oil ExCanO-1, exhibited significantly longer frying life and showed the least changes in its quality indices compared to the three other oil types (P < 0.05) for both seasons. The longer frying life of ExCanO-1, correlated with higher retention of tocopherol and antioxidative capacity of the oil during frying, underscoring the beneficial role of tocopherols on canola oil stability during frying. We hypothesize that the greater retention of tocopherol may have resulted from the presence of minor bioactive compounds in the oil, protecting the tocopherols from heat and oxidative deterioration. The differences in the frying life of the oils were driven by different processing practices employed by the different processors during oil extraction, refining and subsequent handling. This has great implications for oil processors in that there exists the potential to increase the frying life of oil products by adopting intelligent processing approaches. This is because the approach used can improve or adversely impact the quality and frying life of the oil.
|Publication status||Published - 09 Feb 2020|