Influence of refining stages on the physicochemical properties and phytochemicals of canola oil

Abstract

Free fatty acidity and peroxide numbers of canola oil varied between 0.060% (deodorized oil) and 1.090% (crude oil) to 0.15 meqO2/kg (deodorized oil) and 3.00 meqO2/kg (crude oil), respectively. Also, viscosity of oil samples varied between 69.85 mPa (crude oil) and 82.25 mPa (bleached oil). Oleic and linoleic acid contents of canola oils obtained from each refining step were determined between 60.64% (deodorized oil) and 64.04% (neutralized oil) to 19.93% (neutralized oil) and 24.58% (deodorized oil), respectively. The campesterol contents of canola oils taken during rafination were determined between 6.01% (deodorized oil) and 7.90% (bleached oil) while stigmasterol contents of canola oil samples vary between 33.31% (deodorized oil) and 34.81% (bleached oil). While the B and Sn content of the oils increased during refining, Si, P, Fe, N, and Pb contents decreased significantly depending on the refining stages. The refining treatments were used to remove undesirable ingredients and produce higher quality oils in crude canola oil. Practical applications Due to their high saturated fatty acids, vegetable oils are a rich phytochemical (fatty acids, tocopherol, and sterols) sources. In addition, seeds are recognized as a good source of natural oil. The refining treatments were used to remove undesirable ingredients and produce higher quality oils in crude canola oil. Refining processes provide removing the unwanted substances, the most of vitamins, antioxidants, and sterols. The refining steps have specific functions for removing certain minor constituents.