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High performance liquid chromatography with two simultaneous on-line antioxidant assays : evaluation and comparison of espresso coffees
journal contribution
posted on 2010-05-15, 00:00 authored by M Mnatsakanyan, Tiffany Goodie, Xavier ConlanXavier Conlan, Paul FrancisPaul Francis, Geoffrey McDermott, Neil BarnettNeil Barnett, D Shock, F Gritti, G Guiochon, R ShallikerThe antioxidant profiles of various espresso coffees were established using HPLC with UV-absorbance detection and two rapid, simultaneous, on-line chemical assays that enabled the relative reactivity of sample components to be screened. The assays were based on (i) the colour change associated with reduction of the 2,2´-diphenyl-1-picrylhydrazyl radical (DPPH•); and (ii) the emission of light (chemiluminescence) upon reaction with acidic potassium permanganate. Results from the two approaches were similar and reflected the complex array of antioxidant species present in the samples. However, some differences in selectivity were observed. Chromatograms generated with the chemiluminescence assay contained more peaks, which was ascribed to the greater sensitivity of the reagent towards minor, readily oxidisable sample components. The three coffee samples produced closely related profiles, signifying their fundamentally similar chemical compositions and origin. Nevertheless, the overall intensity and complexity of the samples in both UV absorption and antioxidant assay chromatograms were aligned with the manufacturers description of flavour intensity and character.
History
Journal
TalantaVolume
81Issue
3Pagination
837 - 842Publisher
Elsevier B.V.Location
Amsterdam, The NetherlandsPublisher DOI
ISSN
0039-9140eISSN
1873-3573Language
engPublication classification
C1 Refereed article in a scholarly journalCopyright notice
2010, Elsevier B.V.Related work
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