Implications of beta-mercaptoethanol in relation to folate stability and to determination of folate degradation kinetics during processing: a case study on [6S]-5-methyltetrahydrofolic acid.

The effect of β-mercaptoethanol (0−2%) addition to thermally and/or pressure-treated samples on [6S]-5-methyltetrahydrofolate was studied. Degradation of [6S]-5-methyltetrahydrofolate during both thermal and pressure treatments was mainly caused by oxidation, and the oxidized folates could be partly/completely reduced by β-mercaptoethanol. The addition of β-mercaptoethanol (2%) to the thermally and pressure-treated samples overestimated the “actual” stability of [6S]-5-methyltetrahydrofolate and misled the obtained kinetic information. Keywords: [6S]-5-Methyltetrahydrofolate; β-mercaptoethanol; stability; temperature; pressure