Abstract
The effect of the temperature fluctuation in a nominal isothermal stability study is theoretically analyzed using hypothesized temperature-time functions. It is concluded that for symmetrical temperature-time profiles the extent of degradation in the real nonisothermal condition is less than that in the nominal isothermal condition. However, with the temperature fluctuaction obtainable with the current thermoregulated devices, the difference between the two is usually very small and can be neglected except for extremely fast reactions.