TY - JOUR
T1 - High performance liquid chromatography with two simultaneous on-line antioxidant assays : evaluation and comparison of espresso coffees
AU - Mnatsakanyan, Mariam
AU - Goodie, Tiffany A.
AU - Conlan, Xavier A.
AU - Francis, Paul S.
AU - McDermott, Geoffrey P.
AU - Barnett, Neil W.
AU - Shock, David
AU - Gritti, Fabrice
AU - Guiochon, Georges
AU - Shalliker, R. Andrew
PY - 2010
Y1 - 2010
N2 - 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{radical dot}); 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.
AB - 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{radical dot}); 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.
UR - http://handle.uws.edu.au:8081/1959.7/554785
U2 - 10.1016/j.talanta.2010.01.024
DO - 10.1016/j.talanta.2010.01.024
M3 - Article
VL - 81
SP - 837
EP - 842
JO - Talanta
JF - Talanta
IS - 3
ER -