Brazilian fortified wines: Chemical composition, chromatic properties and antioxidant activity

•A study about of chemical composition of white and red Brazilian fortified wines.•Phenolic compounds of Brazilian fortified wines, colour and antioxidant activity.•Minerals, higher alcohols, carbon isotope ratio and phenolic compounds in wines.•Analytical determinations and principal component analysis in Brazilian wines.

The phenolic compounds, minerals and higher alcohols content, carbon isotope ratio, colour and antioxidant activity were determined for samples of white and red fortified wines produced in Brazil, in the regions of the Planalto Catarinense, Serra Gaúcha and Carbonífera Region. The analysis was performed using spectrophotometry, colorimetry, high performance liquid chromatography, inductively coupled plasma mass spectrometry, capillary zone electrophoresis, gas chromatography and isotopic ratio mass spectrometry. The results showed that white and red fortified wines produced in Brazil are active in the scavenging of DPPH and ABTS radicals and in iron reduction. The results for the antioxidant activity of samples of Brazilian fortified wines correlated significantly (p < 0.05) with the content of total polyphenols, ortho-diphenols, tartaric esters, flavonols, total monomeric anthocyanins, total tannins, gallic acid, trans-resveratrol, catechin, caffeic acid, coumaric acid and ferulic acid. The analytical determinations combined with principal components analysis showed the separation of white and red fortified wine samples according to region of origin, with contributions from the variables antioxidant activity, tartaric esters, flavonols, non-polymerized polyphenols, ortho-diphenols, anthocyanins, tannins, total polyphenols, trans-resveratrol, gallic acid, potassium, ethanal, iron, cadmium, sodium, calcium and magnesium. The results obtained showed that fortified red wines produced in the Serra Gaucha show a high concentration of potassium, trans-resveratrol and phenolic compounds along with a high antioxidant activity, while the wines produced in the Planalto Catarinense are notable for their contents of caffeic acid, coumaric acid, cobalt, isoamyl alcohol and isobutanol and their relatively low carbon isotope ratio. White wines produced with the Goethe variety in the Carbonífera Region had low levels of phenolic compounds and minerals.