Title: OXIDATIVE STABILITY OF PURIFIED CANOLA OIL TRIACYLGLYCEROLS FROM GENETICALLY MODIFIED; NORMAL, HIGH STEARIC AND LAURIC ACID; CANOLA VARIETIES AS AFFECTED BY TRIACYLGLYCEROL COMPOSITION AND STRUCTURE
Submitted to: Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 14, 1996
Publication Date: N/A
Interpretive Summary: Genetically modified vegetable oils, like canola oil, are expected to become increasingly important as major components of human foods and animal feed. Vegetable oils are subject to deterioration during processing and storage of foods. This deterioration can cause these foods to become unsuitable for consumption. In this research, the effect of the composition and structure of the basic components of vegetable oils, called triglycerides, on the rate of oil deterioration as been examined. This knowledge is important to plant breeders for development of oilseed varieties with oils of improved storage and shelf life for formulations of foods.
Impact on canola oil oxidative stability with respect to fatty acid, triacylglycerol fatty acid location and triacylglycerol composition was investigated using oils from genetically modified (transgenic) canola varieties. Some of the canola varieties had oils with high content of saturated fatty acids like stearic and lauric. The canola oils were purified of non-triacylglycerol components to allow valid relation of oxidative stability with only the oil triacylglycerols. Accelerated oxidative stability tests permitted investigation of canola oil deterioration at oxidation levels pertinent to oil storage conditions. Rates of formation of peroxide value, triacylglycerol hydroperoxides and triacylglycerol hydroperoxide volatiles were determined for the oxidized canola oil's triacylglycerols. Oxidation results indicated that canola oils of improved oxidative stability compared to normal canola oil resulted from three types of oil modification: a) modification of fatty acid composition accomplished by decrease of readily oxidizable fatty acids like linolenic plus linoleic and increase of oxidation resistant fatty acids like oleic plus increase in saturated fatty acids like stearic and lauric; triacylglycerol structure modification accomplished by increase in oleic and decrease in linoleic at the glycerol moiety carbon 2; composition modification by decrease in linolenic and linoleic containing triacylglycerols and increase in triacylglycerols with stearic and lauric acids in combination with oleic acid.