title: Mechanisms of folate losses during processing: diffusion vs. heat degradation.
abstract: Though folates are sensitive to heat treatments, leaching appears to be a major mechanism involved in folate losses in vegetables during processing. The aim of our study was to study folate diffusivity and degradation from spinach and green beans, in order to determine the proportion of each mechanism involved in folate losses. Folate diffusivity constant, calculated according to Fick's second law (Crank, 1975), was 7.4×10(-12) m(2)/s for spinach and 5.8×10(-10) m(2)/s for green beans, which is the same order of magnitude as for sugars and acids for each vegetable considered. Folate thermal degradation kinetics was not monotonous in spinach and green beans especially at 45 °C and did not follow a first order reaction. The proportion of vitamers changed markedly after thermal treatment, with a better retention of formyl derivatives. For spinach, folate losses were mainly due to diffusion while for green beans thermal degradation seemed to be preponderant.
authors.affiliation: INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, Domaine Saint Paul, Site Agroparc, F-84000 Avignon, France; Université d'Avignon et des Pays du Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France. Electronic address: nicolas.delchier@gmail.com.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Delchier
authors.affiliation: Bioanalytik Weihenstephan, Research Center of Nutrition and Food Sciences, Technische Universität München, Alte Akademie 10, D-85354 Freising, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Ringling
authors.affiliation: INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, Domaine Saint Paul, Site Agroparc, F-84000 Avignon, France; Université d'Avignon et des Pays du Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Maingonnat
authors.affiliation: Bioanalytik Weihenstephan, Research Center of Nutrition and Food Sciences, Technische Universität München, Alte Akademie 10, D-85354 Freising, Germany; Chair of Analytical Food Chemistry, Technische Universität München, Alte Akademie 10, D-85354 Freising, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Rychlik
authors.affiliation: INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, Domaine Saint Paul, Site Agroparc, F-84000 Avignon, France; Université d'Avignon et des Pays du Vaucluse, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France.
authors.forename: Catherine M G C
authors.initials: CM
authors.lastname: Renard
mesh_terms: D005492:Folic Acid / Q000378:metabolism*; D006358:Hot Temperature; D018724:Spinacia oleracea / Q000737:chemistry* / Q000378:metabolism; D014675:Vegetables / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005492:Folic Acid
keywords: Fick’s second law; Folate; Heat degradation; Kinetics; Leaching; Process; Vegetables; Vitamins