title: Redox properties of catechins and enriched green tea extracts effectively preserve L-5-methyltetrahydrofolate: assessment using cyclic voltammetry analysis.
abstract: A cyclic voltammetry (CV) study was performed in pH 5.5 Britton-Robinson buffer at room temperature to study the stability of 1mM l-5-methyltetrahydrofolate (l-5-MTHF) in combination with epigallocatechin-gallate-enriched extract (EGCGe) and epigallocatechin-enriched extract (EGCe). The combination of l-5-MTHF with enriched catechin extracts provided enhanced stability of l-5-MTHF over a period of 12h under ambient air conditions at pH 5.5. CV experiments showed that increasing the concentrations of EGCGe or EGCe extracts from 80 to 400mg/L produced a decrease in the second oxidation peak of l-5-MTHF. Thus, we calculated that l-5-MTHF remained at nearly 90% when in the presence of enriched tea extracts, compared to 74% without the tea antioxidants. The catechins responsible for this preservation were EGCG and C, confirmed by LC-MS. Compared to covalent link only low interaction (hydrogen bonds) between the different catechins present in the tea extract would stabilise l-5-MTHF. Rather, it was hypothesised that EGCGe and EGCe were effective agents to preserve l-5-MTHF, through a mechanism that also involved the redox potential of catechins to maintain l-5-MTHF in its reduced form.
authors: Institute of Nutraceuticals and Functional Foods (INAF) and Department of Food Sciences and Nutrition, Pavilion Paul Comtois, Laval University, Sainte-Foy (QC), Canada G1V 0A6. Elodie.Rozoy.1@ulaval.ca
authors: Elodie
authors: E
authors: Rozoy
authors: Monica
authors: M
authors: Araya-Farias
authors: Stéphan
authors: S
authors: Simard
authors: David
authors: D
authors: Kitts
authors: Jean
authors: J
authors: Lessard
authors: Laurent
authors: L
authors: Bazinet
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry*; D013763:Tetrahydrofolates / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D013763:Tetrahydrofolates; D002392:Catechin; C005984:5-methyltetrahydrofolate