食用油脂自動酸化速度定数の温度依存性

抄録

TTemperature dependency of rate constants of edible oil's autoxidation was estimated. One of us showed ⁽¹⁾ that the rate process of autoxidation of edible oils was expressed by an equation as below, and that the effects of brightness on the rate constants. k₀, k₁, k₂, and k₃, in the equation could be measured individually.
dP/dt=k₀M+k₁MP-2K₂P²-k₃P
Here, P is the concentration [mmol/kg-oil] of peroxides in the oil, and M is that of active methylene residues that are not oxidized yet at time t.
The rate constants k₀, k₁, k₂, and k₃ represent the reaction rates of initiation period, chain reaction period, dimmer formation, and decomposition of P in the termination period of autoxidation, respectively.
In this paper, we show the effects of temperature on the rate constants, i.e., temperature has little effect on k₀ (the activation energy E₀=11kJ/mol), and it has such ordinary effects on k₁, k₂, and k₃, as on a rate constant of a usual chemical reaction (E₁, E₂, E₃=60-90kJ/mol). The results show that the equation is useful to estimate the effects of conditions (processing and preservation) on each stage of autoxidation, and that a simulation can be done with the equation assuming arbitrary temperature conditions.