Thermal degradation of folates under varying oxygen conditions

Nicolas Delchier (1) , Christiane Ringling (2) , Marie-Elisabeth Cuvelier (3) , Francis Courtois (3) , Michael Rychlik (2) , Catherine Renard (1)

1 SQPOV - Sécurité et Qualité des Produits d'Origine Végétale
2 TUM - Technische Universität Munchen - Technical University Munich - Université Technique de Munich
3 GENIAL - Génie industriel alimentaire

Folate losses in thermally treated foods are mainly due to oxidation. Other mechanisms and folate vitamers behaviour are poorly described. Our study evaluated oxygen impact on total folate degradation and derivatives’ evolution during thermal treatments. Spinach and green bean purees were heated, in an instrumented reactor, in anaerobic conditions, under an oxygen partial pressure of 40 kPa. Folates were stable in the absence of oxygen, whilst they were degraded under 40 kPa of oxygen. Total folate showed a sharp decrease in the first hour driven by the degradation of 5-CH3-H4folate, followed by a plateau due to the formyl derivatives and minor compounds stability. The different evolution of the main derivatives was confirmed by the degradation of 5-CH3-H4folate and folic acid in solution, under the same conditions of oxygen concentrations. The stability of folic acid and the high susceptibility of 5-CH3-H4folate to degradation in the presence of oxygen were confirmed.

Mots clés: Vitamin; Heating; Vegetable; Oxidation; Spinach; Green bean; Kinetics

Domaines: Sciences du Vivant [q-bio]

Nicolas Delchier, Christiane Ringling, Marie-Elisabeth Cuvelier, Francis Courtois, Michael Rychlik, et al.. Thermal degradation of folates under varying oxygen conditions. Food Chemistry, 2014, 165, pp.85-91. ⟨10.1016/j.foodchem.2014.05.076⟩. ⟨hal-01173909⟩