Resveratrol, phenolic antioxidants, and saccharides in South American red wines

Abstract: Wine is an important beverage with a long tradition, and its moderate consumption

may be considered beneficial for human health. Although there are many studies regarding

phenolic compounds in wines, there is a lack of information about antioxidants and phenolic

content in South American wines. In this study, 35 South American red wines from

four different countries, vintages 2004–2013, purchased at retail stores in La Paz, Bolivia,

were studied. Resveratrol content, total antioxidant capacity (TAC) by the 2,2′-azinobis(

3-ethylbenzotiazoline-6-sulfonic acid) (ABTS) and ferric-reducing antioxidant power

(FRAP) methods, total phenolic content (TPH), total flavonoids (TF), and main saccharides

were assessed using the well-established spectrophotometric and high-performance liquid

chromatography methods. The results ranged from 4 to 24 mmol/L for TAC determined by

ABTS method and 14 to 43 mmol/L for TAC determined by FRAP method, 1600 to 3500

mg gallic acid equivalents/L for TPH, and 2 to 6 mmol catechin equivalents /L for TF. The

resveratrol content ranged from 0.1 to 8 mg/L. Saccharides, glucose, and fructose content

ranged from 0.4 to 10 g/L, 1.4 to 8.6 g/L, and 0.2 to 12 g/L, respectively. There was a high

correlation among the different methods. The results showed that some wines growing at

high altitude (>1500 meters above the sea level) have higher amounts of TAC and phenolic

content, including resveratrol, while non-varietal wines showed the lowest values. It was

also observed that the saccharose content in some wines was surprisingly high, suggesting

saccharose dosing after fermentation.

Keywords: ABTS, FRAP, high altitude, HPLC, PCA, Bolivia