Microwave-assisted extraction (MW) is scalable to industrial conditions and thus can be adopted by the wine industry. Cabernet Sauvignon grapes with a marked vegetal character were submitted to MW (seven min, peak temperature 53 ± 3°C, n = 24). Untreated control wines were also produced. All wines were produced in triplicate with 12 days maceration and were followed for phenolics and color from pressing up to three months of bottle aging (BA). MW reduced total yeast counts. Ethanol, titratable acidity, malic acid, lactic acid, dry extract, and glycerol were more concentrated in MW wines. Extraction of anthocyanins, tannins, and total phenolics at pressing was 36, 26, and 27% higher in MW wines. After three months of BA, anthocyanins declined 42% in MW wines and 21% in control wines; tannins declined 45% and 29%, respectively. As a result, after three months BA, there were no differences between MW and control wines for anthocyanins, tannins, total phenolics, color hue, or polymeric pigments, but wine color (AU 420 + 520 + 620 nm) remained higher in MW wines. Descriptive sensory analysis with a trained panel (n = 21) found that MW wines had greater color saturation, purple color, fruity aroma, astringency, and bitterness than control wines. Additionally, MW reduced the vegetal character of the MW wines. Overall, MW applied to Cabernet Sauvignon grapes had a positive effect on phenolic extraction that was observable early during winemaking, but the rate of loss of phenolics in MW wines was higher than in control wines. Although the long-term phenolic and chromatic composition of MW was not significantly altered relative to a control, MW was a viable option to manage the vegetal character of Cabernet Sauvignon wines while positively altering mouthfeel and taste properties.

Funding Support: INTA