Influence of some experimental variables and matrix components in the determination of antioxidant properties by β-carotene bleaching assay: experiments with BHT used as standard antioxidant

Abstract

The b-carotene bleaching assay belongs to the oldest and continuously commonly applied methods of estimating the antioxidant activity of compounds and mixtures. In this method, the antioxidant activity of the examined substance is evaluated by the spectrophotometric measurement of b-carotene concentration changes in bcarotene/peroxyl radicals (LOO • ) systems with and without antioxidant. Yet a little is known about factors influencing the value of inhibition percent of the investigated antioxidant, estimated by this method. The paper shows that both the antioxidant solvent type and the amount of the antioxidant solvent in the measuring system significantly influence the inhibition percent value for butylohydroxytoluene (BHT), used as standard antioxidant in the performed experiments. Moreover, the results shown in the paper prove the essential influence of hydrogen and metal ions on the results of antioxidant assay. The relationships discussed in this paper indicate the necessity of standardizing b-carotene method and reveal the complexity of the problem of estimation of adequate antioxidant activity of examined substances.

Measurement of antioxidant activity

“…The β-carotene bleaching assay in different versions has been applied in the assessment of various synthetic and natural antioxidant extracts. It was recently suggested that standardization of this method is necessary as the results can be significantly influenced by a number of factors, such as type and amount of solvent in which the antioxidants are dissolved, and presence of hydrogen and metal ions, among others (Dawidowicz & Olszowy, 2010).…”

The Methodology Applied in DPPH, ABTS and Folin-Ciocalteau Assays Has a Large Influence on the Determined Antioxidant Potential

“…Apart from their structural characteristics (number and position of -OH groups, inductive effects of other substituents present in the antioxidant molecule, steric hindrance/accessibility, packaging of an antioxidant around reactive species) the reactivity of an antioxidant depends significantly on reaction conditions such as solvent polarity, pH, temperature, type and concentration of reactive species. 3,[6][7][8][9][10][11][12][13][14] Since the selection of the method, the time and reaction conditions adopted to evaluate the content of antioxidants in a given sample significantly impact the determined values and, due to the fact that these parameters in a number of articles are relatively poorly described, it is very difficult to compare the results of AOP obtained for similar samples in different studies.…”

The importance of solvent type in estimating antioxidant properties of phenolic compounds by ABTS assay

“…It has been demonstrated [17] that the reaction kinetics between an antioxidant and peroxyl radicals in this method depends on the solvent type which account for the estimated antioxidant properties of the examined compounds. A question appears whether solvent type also influences the estimation of antioxidant properties of compounds by ABTS assay.…”