- Effect of Canolol on Oxidation of Edible Oils
Canola oil is one of the most important vegetable oils in the world after palm oil and soyabean oil and is ranked third in world production. The fatty acid composition of the oil is characterized by a high content of oleic acid of about 60% and a moderate content of α-linolenic acid of about 10%. The relative high content of α-linolenic acid and the ratio between ω-6 and ω-3 fatty acids of 2:1 makes canola oil attractive oil nutritionally. In addition to the fatty acids, canola oil is relatively rich in tocopherols and phytosterols, which are important to health, but also improve the oxidative stability of vegetable oils. In comparison with other major oilseeds, canola seeds also contain comparatively high amounts of phenolic compounds (Naczk et al., 1998). However, during oil extraction with a screw press or expeller, in the absence of solvent extraction, only a few of the phenolic compounds go into the oil with the main part remaining in the press cake (Vuorela et al., 2003). Virgin extra olive oil is a particularly important cold-pressed oil. It has a high content of phenolic compounds that signicantly improve the oxidative stability of this type of oil (Figure 17.1).