Isothermal microcalorimetry has been applied as a method for predicting (in)stability of ascorbic acid and several amino acids
that undergo oxidative degradation in aqueous media. The fast and simple method involved the addition of different amounts
of hydrogen peroxide. The appearance of the heat flow curves gave a clear general indication of how stability was influenced.
The accuracy of the microcalorimetric result was investigated by comparing it with an HPLC assay and a good agreement between
the results of both methods was demonstrated. It was also established that susceptibility to oxidative degradation decreases
in the following order: cysteine, methionine, ascorbic acid, tyrosine and tryptophan.