Seventy wines were produced in Ecuador under different processing conditions with local fruits: Andean blackberries (Rubus glaucus Benth.) and blueberries (Vaccinium floribundum Kunth.) and Golden Reinette apples. Wines were evaluated for antioxidant activity (AA) using the radical scavenging capacity (DPPH) method, total phenolic content (TPC) using the Folin-Ciocalteu method, total monomeric anthocyanins (TMAs) using the pH differential test, and color parameters using VIS-spectrophotometry. For blackberry wines, ellagitannins and anthocyanins were also analyzed using high-performance liquid chromatography with diode-array detection (HPLC-DAD). Apples wines (n = 40) had the lowest TPC (608 ± 86 mg/L) and AA (2.1 ± 0.3 mM Trolox). Blueberry wines (n = 12) had high TPC (1086 ± 194 mg/L) and moderate AA (5.4 ± 0.8 mM) but very low TMA (8 ± 3 mg/L), with a color evolved toward yellow and blue shades. Blackberry wines (n = 10) had the highest TPC (1265 ± 91 mg/L) and AA (12 ± 1 mM). Ellagitannins were the major phenolics (1172 ± 115 mg/L) and correlated well with AA (r = 0.88). Within anthocyanins (TMA 73 ± 16 mg/L), cyanidin-3-rutinoside (62%) and cyanidin-3-glucoside (15%) were predominant. Wines obtained by cofermentation of apples and blackberries (n = 8) showed intermediate characteristics (TPC 999 ± 83 mg/L, AA 6.2 ± 0.7 mM, TMA 35 ± 22 mg/L) between the blackberry and blueberry wines. The results suggest that the Andean berries, particularly R. glaucus, are suitable raw materials to produce wines with an in vitro antioxidant capacity that is comparable to red grape wines.
Keywords: anthocyanin; antioxidant activity; fruit; polyphenols; wine.
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