3.1.1. Higher alcohols
Three higher alcohols were detected above their threshold, isobutanol, isopentanol and 2-phenylethanol, and their OAVs were higher in IF wine than in SF wine (Table 2). Higher alcohols can have both a positive and negative impact on the aroma and flavor of wine, depending on their concentrations. An excessive concentration (exceeding 400 mg/L) can result in a strong, pungent smell. The concentration of 300-400 mg/L is acceptable, whereas the optimal level (below 300 mg/L) imparts a pleasant character (Rapp & Versini, 1991). Total concentrations of higher alcohols of 896.7 mg/L and 674.2 mg/L were produced in IF and SF wines, respectively, suggesting that they negatively impact to the aroma of wine. This could be ascribed to the cold maceration technology applied in this work. According to the literature data, cold maceration can evoke an increased amount of higher alcohols by extracting aromatic components and precursors from grape skins
(Petropulos et al., 2014).