Antioxidant activity comparison between [6S]-5-methyltetrahydrofolic acid calcium salt and the related racemate form

► [6S]-5-MTHF and its racemate [6R,S] form were evaluated by TEAC, FRAP and ORAC assays. ► In the TEAC assay, [6S] form had higher antioxidant activity versus its racemate form. ► Similar antioxidant activity values in the FRAP and ORAC assays. ► Stereoisomery influences the antioxidant activity of 5-MTHF.