The kinetics of change in peroxide value and weight gain were simultaneously studied during peroxidation of three vegetable oils of various chemical compositions. The initia-tion and propagation oxidizability parameters Oi (kg mEq–1 h2) and rn (h–1) of the canola, corn, and peanut oils were calculated to be 412 and 0.0894, 160 and 0.0641, and 36.1 and 0.0304, respectively. The weight-based parameter Oiw ranked the oils (103000, 51000, and 8000 %h2, respectively) as the parameter Oi did. However, the equivalent parameter rnw (0.0680, 0.1198, and 0.1875 h–1, respectively) provided a reverse order than that of the pa-rameter rn. This was attributed to the fact that the value of rn represents the formation and decomposition of lipid hydroperoxides in general, whereas the value of rnw stands actually for the overall tendency of an oil to the formation and polymerization of lipid hydroper-oxides.

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