Comparison of Total Phenolic Content and Total Antioxidant Activity in Local Red Wines Determined by Spectrophotometric Methods

Abstract

Stratil P., Kubáň V., Fojtová J. (2008): Comparison of the phenolic content and total antioxidant activity in wines as determined by spectrophotometric methods. Czech J. Food Sci., 26: 242-253. Folin-Ciocalteu reagent (FCM) and Price and Butler method (PBM) were used for spectrophotometric determination of the total content of phenolic compounds in 29 wines (8 white, 21 red). The average contents of phenolic compounds determined by FCM and PBM were 108 (90-119) and 105 (90-129) for white wines, and 1545 (874-2262) and 547 (306-816) mg/l of gallic acid equivalents (GAE) for red wines, respectively. The reason for the lower PBM values in red wines is the higher reactivity in PBM of phenolic compounds, especially of gallic acid generally used as a standard in the above methods. The higher reactivity of the standard means that the measured absorbance of the sample responds to a lower concentration. The average total antioxidant activities determined by TEAC (Trolox Equivalent Antioxidant Capacity), FRAP (Ferric Reducing Antioxidant Power), and DPPH (using diphenyl-p-picrylhydrazyl radical) were 5.14 (4.30-6.14), 1.43 (0.86-2.14), and 0.71 (0.61-0.81) of Trolox equivalents (TE) and 26.44 (13. 9-34.4), 9.43 (4.92-13.9), and 5.52 (2.91-8.62) mmol/l TE for white and red wines, respectively. Almost the same molar absorptivities with TEAC and DPPH methods were found while with FRAP method it was somewhat higher (about 1.56-times). The ratio of the values determined by FRAP and DPPH methods for white and red wines were 2.0 and 1.7, respectively. The TEAC values were 2.8-and 4.8-fold higher than those determined by FRAP and DPPH methods, respectively. The radical ABTS •+ used in TEAC method is therefore the most reactive and responds to the highest number of hydroxyl groups of the phenolic compounds of wines.

Antioxidant activities of tropical fruit wines

“…Phenolic compounds can be considered good indicators of antioxidant activity in the fermented products, as their content significantly correlated ( p < 0.01) with antioxidant activity determined by DPPH and FRAP methods. This confirms the major role of phenolic compounds in antioxidant activity .…”

Determination of some individual phenolic compounds and antioxidant capacity of mead produced from different types of honey

“…A good correlation between the antioxidant capacity and total phenolic content has been determined in some studies. However, the relationship between individual phenolic componds and antioxidant capacity was unclear (62,63).…”

Influence of Mycorrhiza and Different Yeast Strains on Physical, Chemical and Organoleptic Properties of Graševina (Vitis vnifera L.) Wine

“…They also concluded that besides the previously mentioned antioxidants, antioxidant activity depends not only on the phenolic concentration, but also on the specific chemical structure of each phenolic compound. Previous researches showed good a correlation between the total polyphenols content and antioxidant activity in red wines (Büyüktuncel et al, 2014, Piljac-Ţegarac et al, 2007, while the correlation in white wines varieties was low (Piljac-Ţegarac et al, 2007). As it can be seen (Figures 2 and 3) antioxidant activity shows very bad correlation to polyphenol content regardless of the method used for antioxidant activity determination.…”