Assessing the association between phenolic compounds and the antioxidant activity of Brazilian red wines using chemometrics

Abstract

a b s t r a c tThe objective of this study was to evaluate the association among chemical parameters, the commercial value, and the antioxidant activity of Brazilian red wines using chemometric techniques. Twenty-nine samples from five different varieties were assessed. Samples were separated into three groups using hierarchical cluster analysis: cluster 1 presented the highest antioxidant activity towards DPPH (68.51% of inhibition) and ORAC (30,918.64 mmol Trolox Equivalents/L), followed by cluster 3 (DPPH ¼ 59.36% of inhibition; ORAC ¼ 25,255.02 mmol Trolox Equivalents/L) and then cluster 2 (DPPH ¼ 46.67% of inhibition; ORAC ¼ 19,395.74 mmol Trolox Equivalents/L). Although the correlation between the commercial value and the antioxidant activity on DPPH and ORAC was not statistically significant (P ¼ 0.13 and P ¼ 0.06, respectively), cluster 1 grouped the samples with higher commercial values. Cluster analysis applied to the variables suggested that non-anthocyanin flavonoids were the main phenolic class exerting antioxidant activity on Brazilian red wines.

Botanical Extracts Used as Wine Preservatives

“…It is difficult to confront our values of antioxidant activity with the literature data since similar experiments are very scarce in the literature. However the majority of authors used various methods for determining antioxidant activity in wines such as the inhibition of lipid oxidation, DPPH method with the evaluation of EC50 (the sample concentration necessary to reduce the remaining DPPH by 50%), and ORAC method (Oxygen Radical Absorbance Capacity) [7][8][9]. It is possible to compare, in part, some of the values determined by the method TEAC using ABTS radical.…”

“…The total volume used in the original procedure [8,9,12,13] was reduced to 1 ml. The stock solution, a 1:1 (v/v) mixture of ABTS (7 mmol/l) and potassium persulfate (4.95 mmol/l), was left to stand for 12 h at laboratory temperature in dark to form radical-cation ABTS•+.…”

Cytotoxic effect and antioxidant activity of Andean berry (Vaccinium meridionale Sw) wine

“…This author reported a value of 1836 ± 40.5 mg GAE eq/L for Karpat wine and 3466 ± 54.4 mg GAE eq/L for Buzbag wine in totals phenols. Besides, Granato et al (2010) reported a range of 1041. 63 -1958.78 mg GAE/L for Brazilian red wines.…”

Monitoring the authenticity of Brazilian UHT milk: A chemometric approach

“…The results, qualitative in nature, are usually presented as a dendrogram, allowing the visualisation of clusters and correlations among samples or variables. In HCA, the Euclidean distances between samples or variables are calculated and transformed into a similarity matrix whose elements are similarity indexes ranging from 0 to 1; a smaller distance means a larger index and therefore, a larger similarity (Granato, Castro, & Katayama, 2010). Principal Component Analysis (PCA), on the other hand, is based on the correlation among variables.…”