Thermal Oxidation Studies on Reduced Folate, L-5-Methyltetrahydrofolic Acid (L-5-MTHF) and Strategies for Stabilization Using Food Matrices

Yazheng Liu, Stephen Tomiuk, Elodie Rozoy, Stephan Simard, Laurent Bazinet, Timothy Green, David D. Kitts

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


The thermal stability of L-5-methyltetrafolic acid (L-5-MTHF) was investigated in model/buffer systems and food systems. L-5-MTHF degradation followed first-order reaction kinetics with relatively greater (P < 0.01) stability at pH 4 compared to pH 6.8 in the buffer systems. This was confirmed using cyclic voltammetry. The stability (for example, k-values) of L-5-MTHF in an oxygen controlled environment improved (P < 0.001) proportionally when in the presence of increasing molar ratios of sodium ascorbate (NaAsc). The addition of NaAsc to L-5-MTHF after heat treatment was also effective at returning thermally oxidized L-5-MTHF back to its original form. A scheme was developed to explain the degradation and regeneration of L-5-MTHF. The importance of antioxidant protection of L-5-MTHF from thermal oxidation was extended using 2 distinct food systems; namely skim milk and soy milk, both with known antioxidant capacities. We conclude that the antioxidant activity of food components can enhance the stability of L-5-MTHF.

Original languageEnglish
JournalJournal of Food Science
Issue number2
Publication statusPublished or Issued - 1 Feb 2012
Externally publishedYes


  • Antioxidant
  • Food matrices
  • L-5-methyltetrahydrofolic acid
  • Thermal stability

ASJC Scopus subject areas

  • Food Science

Cite this