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Evaluation of free radical scavenging of dietary carotenoids by the stable radical 2,2‐diphenyl‐1‐picrylhydrazyl
Author(s) -
JiménezEscrig Antonio,
JiménezJiménez Isabel,
SánchezMoreno Concepción,
SauraCalixto Fulgencio
Publication year - 2000
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/1097-0010(20000901)80:11<1686::aid-jsfa694>3.0.co;2-y
Subject(s) - dpph , chemistry , antioxidant , absorbance , lutein , carotenoid , xanthophyll , ec50 , food science , carotene , organic chemistry , chromatography , biochemistry , in vitro
In order to avoid the interference of compounds with a chromophoric system when the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH · ) method is used, a new measure of the decrease in absorbance at 580 nm was performed (correlation coefficient between absorbance and DPPH · concentration, 0.9979; p < 0.01). The antioxidant effectiveness of dietary carotenes and xanthophylls towards the stable free radical DPPH · was measured. The antioxidant activity expressed as the amount of antioxidant able to reduce the initial DPPH · concentration to 50% (EC 50 ), given in terms of moles of antioxidant per mole of DPPH · , ranged from 0.16 ± 0.01 (lycopene) to 3.29 ± 0.31 (lutein). The parameter antiradical efficiency (AE), which involves the potency (1/EC 50 ) and the time taken to reach the steady state at EC 50 ( T EC50 ), was calculated to discriminate carotenoids with no significant difference between their EC 50 . Comparison of the structures of the carotenoids tested revealed that the scavenging ability towards DPPH · was increased by the length of the effective conjugated double‐bond system and was modulated by the addition of chemical groups on the terminal rings (xanthophylls). © 2000 Society of Chemical Industry