Background:
The consumption of herbal teas has gained much attention due to its healthpromoting
benefits, including antioxidant, neuroprotective, antimicrobial, antitumor, and antiinflammatory
effects. These biological activities are associated in part to the antioxidant activity of
chemical compounds present in teas, especially flavonoids and phenolic acids.
Objective:
The aim of this study was to evaluate a total of 17 different botanical herbal infusions consumed
in Brazil in terms of their phenolic antioxidants.
Methods:
The analysis performed were total phenolic compounds, total flavonoids, total flavonols,
tannin content and in vitro antioxidant activity (DPPH, ABTS, CUPRAC, FRAP, and ORAC assays).
Data were processed using univariate, bivariate and multivariate analysis (hierarchical cluster analysis).
Results:
The use of Hierarchical Cluster Analysis (HCA) suggested an unsupervised classification relationship
based on level of functionality of the herbal teas. Higher levels of total phenolics, total flavonoids
and antioxidant activity were found in Anemopaegma mirandum while higher values of tannin
content and total flavonols were found in Peumus boldus. All antioxidant activity assays showed significant
correlations among each other (r > 0.84, p < 0.001), and with total phenolic and flavonoids (r
> 0.83, p < 0.001). Using HCA, three clusters were suggested and cluster 1 showed the highest functionality.
Conclusion:
The herbal infusions evaluated can be a good resource of bioactive compounds to consume
and supplementing food products. Nevertheless, future studies should focus on the evaluation of
these herbal teas using in vivo systems to understand the mechanisms of action when these different
herbal infusions are used as beverages.
Application of principal component and hierarchical cluster analysis to classify different spices based on in vitro antioxidant activity and individual polyphenolic antioxidant compounds
