Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria (EEA Mendoza INTA), San Martín 3853, M5507EVY, Luján de Cuyo, Mendoza, Argentina; Centro de Estudios Vitivinícolas y Agroindustriales, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP5519 Guaymallén, Mendoza, Argentina.
Estación Experimental Mendoza, Instituto Nacional de Tecnología Agropecuaria (EEA Mendoza INTA), San Martín 3853, M5507EVY, Luján de Cuyo, Mendoza, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Food Res Int. 2022 Jun;156:111169. doi: 10.1016/j.foodres.2022.111169. Epub 2022 Mar 21.
Bonarda, the second red grape variety in Argentina, produces high yields per hectare generating, in several cases, low quality wines. Microwave-assisted extraction (MW) is a novel extraction technique for winemaking, widely applied in other foods. Stems addition (S) during vinification can be a sustainable technology for phenolic and aroma contribution without additional cost. Therefore, this study aimed to evaluate the combined effect of MW application with stem additions in different conditions, before fermentation, on the chemical composition of Bonarda wines. During two consecutive vintages (2018 and 2019), the experimental design consisted of ten treatments (two factors) by triplicate. Two maceration strategies (Factor 1) were applied [control (C), and microwaved-assisted extraction after grape crushing (MW; 2450 MHz, 7600 W, 45-50 °C)], combined with five stem-contact conditions (Factor 2) [control without stems (WS), 50% stems addition (S50), 50% stems addition + MW of the stems (S50MW; 2450 MHz, 7600 W, 60 °C), 100% stems addition (S100), 100% stems addition + MW (S100MW)]. Wines were analyzed for basic chemistry, phenolic composition and color parameters, polysaccharides, and aroma profiles. The 2018 wines showed higher pH and lower volatile acidity with stem additions and MW application in both matrices (grapes and stems). Stem additions increased tannin content by >55% (S100) and by >25% for the other treatments; while MW, mostly in the 2018 season, consistently improved phenolic extraction and polymeric pigments formation, enhancing wine color (greater saturation) and intensifying violet hue. The behavior observed in 2019 was similar, with a more marked effect of MW on wine color (C* and polymeric pigments). Likewise, combined strategies increased polysaccharides extraction and modified the volatile profile of wines. The reported results are promising and are considered the first advance in the knowledge of the impact of the proposed combined strategies on the chemical composition of red wines.
宝娜达是阿根廷的第二大红葡萄品种，其每公顷的产量很高，但所产葡萄酒的质量往往较低。微波辅助提取（MW）是一种新颖的酿酒提取技术，在其他食品中也得到了广泛应用。在发酵过程中添加茎秆（S）可以为葡萄酒带来酚类物质和香气贡献，且无需额外成本，是一种可持续的技术。因此，本研究旨在评估 MW 应用与不同条件下茎秆添加相结合（发酵前）对宝娜达葡萄酒化学组成的综合影响。在两个连续的葡萄收获年份（2018 年和 2019 年）中，实验设计由三个重复的十个处理（两个因素）组成。采用两种浸渍策略（因素 1）[对照（C）和葡萄破碎后微波辅助提取（MW；2450MHz，7600W，45-50°C）]，结合五种茎秆接触条件（因素 2）[对照无茎秆（WS）、50%茎秆添加（S50）、50%茎秆添加+MW 处理的茎秆（S50MW；2450MHz，7600W，60°C）、100%茎秆添加（S100）、100%茎秆添加+MW（S100MW）]。对葡萄酒的基础化学、酚类成分和颜色参数、多糖和香气特征进行了分析。2018 年的葡萄酒表现出较高的 pH 值和较低的挥发性酸度，且茎秆添加和 MW 应用均增加了两种基质（葡萄和茎秆）中葡萄酒的稳定性。添加茎秆可使单宁含量增加超过 55%（S100），其他处理的单宁含量增加超过 25%；而 MW 主要在 2018 年提高了酚类物质的提取和聚合色素的形成，增强了葡萄酒的颜色（更大的饱和度），并增强了紫罗兰色调。2019 年的表现相似，MW 对葡萄酒颜色（C*和聚合色素）的影响更为明显。同样，联合策略增加了多糖的提取，改变了葡萄酒的挥发性特征。所报道的结果很有前景，被认为是首次在知识上了解到所提出的联合策略对红葡萄酒化学组成的影响。
