title: Antioxidant Capacity: Experimental Determination by EPR Spectroscopy and Mathematical Modeling.
abstract: A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.
authors.affiliation: †Department of Materials Chemistry and Chemical Technology and ‡Department of Physical Chemistry, Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
authors.forename: Justyna
authors.initials: J
authors.lastname: Polak
authors.affiliation: †Department of Materials Chemistry and Chemical Technology and ‡Department of Physical Chemistry, Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
authors.forename: Mariola
authors.initials: M
authors.lastname: Bartoszek
authors.affiliation: †Department of Materials Chemistry and Chemical Technology and ‡Department of Physical Chemistry, Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Chorążewski
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry*; D001628:Beverages / Q000032:analysis; D001713:Biphenyl Compounds; D004578:Electron Spin Resonance Spectroscopy; D005504:Food Analysis / Q000379:methods*; D008962:Models, Theoretical; D010851:Picrates; D017365:Spices / Q000032:analysis; D013662:Tea / Q000737:chemistry; D014920:Wine / Q000032:analysis
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D010851:Picrates; D013662:Tea; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: EPR spectroscopy; Trolox equivalent antioxidant capacity (TEAC); antioxidant capacity; mathematical modeling