[en] The influence of sample dilution on the measurement of antioxidant capacity was analyzed. To ensure the reproducibility of results it is necessary to realize such scarce investigations. This study focuses on different antioxidant capacity assays, commonly used for the analysis of pure substances and food extracts. For all compounds and foods tested in most of the four assays (TEAC, DPPH and ORAC), effects of sample dilution on the measured (and recalculated) antioxidant capacity were observed, differences up to 28% between dilutions. An extrapolation method was proposed to obtain a “real value” thus to minimize the effects of the sample dilution. This extrapolation method is relatively simple, based on a linear regression of 4 or 5 appropriate dilutions of the sample and applicable to the various assays. The use of such a method will improve the consistency of inter-laboratory antioxidant capacity data and thus permit better comparisons. In contrast, there was no dilution problem with FRAP assays.
Disciplines :
Food science
Author, co-author :
Sipel, Arnaud; Université de Liège - ULiège > Sciences de la vie > Biologie Moléculaire et Biotechnologie Végétales
Kevers, Claire ; Université de Liège - ULiège > Département des sciences de la vie > Département des sciences de la vie
PINCEMAIL, Joël ; Centre Hospitalier Universitaire de Liège - CHU > Chirurgie cardio-vasculaire
Grygel, Pierre-Gabriel; Université de Liège - ULiège
DEFRAIGNE, Jean ; Centre Hospitalier Universitaire de Liège - CHU > Chirurgie cardio-vasculaire
Dommes, Jacques ; Université de Liège - ULiège > Département des sciences de la vie > Biologie moléculaire et biotechnologie végétales
Language :
English
Title :
Sample dilution influences the determination of antioxidant capacity in food. How to minimize it?