Volatile components from triolein heated in air

In a continuing study to identify volatile odor constituents and their precursors from heated soybean oil, the following model triglycerides were heated to 192 C in air for 10 min: (a) pure triolein, (b) a mixture of triolein (25%)-tristearin, and (c) a randomly esterified triglyceride composed of oleic (25%) and stearic acids. Each model system produced the same major compounds which were identified as heptane, octane, heptanal, octanal, nonanal, 2-decenal, and 2-undecenal. These seven compounds apparently are unique to the oxidation of the oleate fattyy acid in each triglyceride sample. Minor volatile compounds from oxidized triolein included saturated and unsaturated aldehydes andn-hydrocarbons and saturated primary alcohols, methyl ketones, gamma lactones, and monobasic acids. Incorporation of stearic acid in the triglycerides noticeably increased the amounts of saturated minor compounds and the range of their carbon chain lengths. Decomposition products characteristic of the oxidation of stearate were apparent among decomposition products associated with the oxidation of oleate.