Effect of Oxygen on Thermal Degradation of 5‐Methyl‐5,6,7,8‐Tetrahydrofolic Acid

Previous studies of thermal degradation of folic acid have not given consistent rate expressions or activation energies. The present study employed a model system which eliminated oxygen mass transfer limitations to examine degradation as a result of heating. A pseudo first‐order reaction rate constant (k 365.K ) and an activation energy (E a ) for thermal degradation due to an oxidative mechanism were estimated to be 0.154 ± 0.044 min −1 and 16.3 kcal/mol, respectively. In the presence of N 2 , these parameters were estimated to be 0.094 ± 0.009 min −1 and 23.3 kcal/mol, respectively. While elimination of oxygen will not ensure folic acid retention, the overall degradation rate will be reduced significantly.