title: EPR study of free radicals in bread.
abstract: The features of the recorded EPR spectra of paramagnetic species formed in bread and rusk are reported. The appearance of free radicals in them is only connected with their thermal treatment since the starting materials (flour and grains) exhibit very weak EPR signal. The obtained EPR spectra are complex and indicate that: (i) the relative number of paramagnetic species depends on the temperature and treating time of the raw product; (ii) the g-values are strongly temperature dependent with a tendency to coincide at t > or = 220 degrees C. Because of the relatively low (150-220 degrees C) temperature of thermal treatment, the studied free radicals can be assumed to appear in the course of the browning (Maillard) reaction and not to the carbonization of the material.
authors.affiliation: Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. ndyepr@bas.bg
authors.forename: Nicola D
authors.initials: ND
authors.lastname: Yordanov
authors.forename: Ralitsa
authors.initials: R
authors.lastname: Mladenova
mesh_terms: D001939:Bread; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000032:analysis*; D015416:Maillard Reaction; D013696:Temperature; D013997:Time Factors
chemical_list: D005609:Free Radicals