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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 Shalliker
The 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

Talanta

Volume

81

Issue

3

Pagination

837 - 842

Publisher

Elsevier B.V.

Location

Amsterdam, The Netherlands

ISSN

0039-9140

eISSN

1873-3573

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2010, Elsevier B.V.

Related work

DU:30042598