Effect of Microwave Radiation on Thiamin Degradation Kinetics

A new technique for studying reaction kinetics was used to confirm evidence for the absence of non-thermal microwave effects on the thermal degradation of vitamin B1. An additional experiment was performed to determine whether exposure of the vitamin to relatively high power microwaves (400W), at low temperatures (< 30°C), induced degradation which would not normally be expected in the absence of microwave exposure. For the first experiments, a special microwavable reaction vessel was used to determine rates of vitamin B1 degradation due to microwave exposure at controlled steady-state temperatures of 100, 110, 120 and 130°C. Degradation rates from equivalent conventional heating experiments were compared to those from microwave heating. Both studies indicated that the effect of microwave radiation on thiamin degradation was solely thermal in nature. Rates of degradation were found to be similar at the 95% confidence level. No difference was found between microwave irradiated and unirradiated thiamin samples when temperatures were maintained at low temperatures.