Degradation kinetics of folic acid in cowpea (Vigna catjang L.) during cooking.

Kinetics of folic acid degradation in cowpea (Vigna catjang L.) as well as in pure folic acid solutions at initial concentrations present in cowpea over a temperature range of 50-120 degrees C (isothermal conditions) followed first order reaction kinetics, where the rate constant increased with an increase in temperature. The temperature dependence of degradation was adequately modeled by Arrhenius equation. The degradation was also evaluated in normal open pan cooking, pressure-cooking and a newly developed and patented fuel-efficient Eco Cooker (non-isothermal heating process). A mathematical model was developed using the isothermal kinetic parameters obtained to predict the losses of folic acid from the time-temperature data of the non-isothermal heat processing method. The results obtained indicate the folic acid degradation is of a similar order of magnitude in all the methods of cooking.