Sensitivity of phenolic compounds evaluated by a new approach of analytical methods

Phenolic compounds have a great diversity of substances, ranging from simple molecules to complex polymers. Therefore, it has been a great challenge to relate the behavior these substances, which may cause variations in the results obtained. For this, the objective of this work was to evaluate the behavior of phenolic compounds belonging of different classes (hydroxybenzoic; hydroxycinnamic acids; flavonols; flavonols (catechins) and synthetic compounds) employing a new approach of analytical methods through sensitivity for each method. Results were statistically evaluated using principal component analysis ( PCA ) and Tukey’s test methodologies. The compounds sensitivity was obtained from the inclination of the standard curves constructed for each standard phenolic compound. Limits of detection ( LOD ) and quantification ( LOQ ) were calculated for each compound through the relation between uncertainty of the intercept ( Sa ) and slope ( b ), they presented different behavior comparing the methodologies, even compounds belonging to the same class. Moreover, 4-hydroxybenzoic acid compound did not show sensitivity to the methods 2,2-Diphenyl-1-picrylhydrazyl (DPPH ˙ ) and Ferric Reducing Ability Power ( FRAP ) . Limits of detection and quantification also varied according to the compound and method investigated. The results interpretation was better examined applying the principal component analysis, PCA , rearranging the data in new coordinates. Hence, this study indicated that in general the ORAC methodology provides the best results in relation to the analysis of these different phenolic compounds and was indicated to evaluate the antioxidant capacity of most of the compounds analyzed. This correlation can be investigated in future studies, applying in real samples, indicating which methodology will be the most appropriate depending on the antioxidant composition in food.