Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    An on-line high performance liquid chromatography-crocin bleaching assay for detection of antioxidants
    Bountagkidou, O. ; Klift, E.J.C. van der; Tsimidou, M.Z. ; Ordoudi, S.A. ; Beek, T.A. van - \ 2012
    Journal of Chromatography. A, Including electrophoresis and other separation methods 1237 (2012). - ISSN 0021-9673 - p. 80 - 85.
    radical scavenging compounds - chemiluminescence detection - natural antioxidants - complex-mixtures - identification - capacity - extracts - inhibition - plant
    An on-line HPLC (high performance liquid chromatography) method for the rapid screening of individual antioxidants in mixtures was developed using crocin as a substrate (i.e. oxidation probe) and 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH)) in phosphate buffer (pH 7.5) as a radical generator. The polyene structure of crocin and AAPH-derived peroxyl radicals resemble the lipidic substrates and radicals found in true food more closely than the popular, albeit artificial, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS+ (2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate)) do. After separation by a C18 (octadecyl silica) column and UV (ultraviolet) detection, antioxidative analytes react with peroxyl radicals at 90 °C and the inhibition of crocin oxidation (i.e. bleaching) is detected as a positive peak by an absorbance detector at 440 nm. The method is simple, uses standard instruments and inexpensive reagents. It can be applied for isocratic HPLC runs using mobile phases containing 10–90% organic solvent in water, weak acids or buffers (pH 3.5–8.5). With baseline correction, gradient runs are also feasible. The radical scavenging activity of several natural antioxidants and a green tea extract was studied. After optimisation of conditions such as reagent concentrations and flows, the limit of detection varied from 0.79 to 7.4 ng, depending on the antioxidant. --------------------------------------------------------------------------------
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