Maturation and Maceration Effects on Tropical Red Wines Assessed by Chromatography and Analysis of Variance - Principal Component Analysis

Effects of grape maturity, maceration length during winemaking and interaction of both of them on physicochemical parameters, phenolic and volatile composition were investigated in tropical Syrah wines with the aim of finding the best conditions to produce wines that are rich in phenols and positive aroma active compounds. A headspace solid phase micro extraction and gas chromatography with mass spectrometry (HS-SPME-GC-MS) method was improved and validated for the analysis of 41 volatiles. Principal component analysis (PCA) and analysis of variance (ANOVA)-PCA coupled with inspection of statistically significant loadings were important to access the effects of maturation and maceration on wine composition. Wines made from riper grapes (21-23 ºBrix) stood out in relation to color intensity, total phenolic compounds, and presented high levels of anthocyanins, flavonols, procyanidin A2, and linalool (floral). Thirty days of maceration were linked to higher levels of some flavan-3-ols, gallic acid, a few esters (fruity) and alcohols, (E)-nerolidol (floral), while nonanoic acid (unpleasant aroma) reduced its concentration with prolonged maceration.

本研究以热带产区西拉（Syrah）葡萄酒为研究对象，探究葡萄成熟度、酿酒浸渍时长以及二者的交互作用对葡萄酒理化指标、酚类物质与挥发性成分的影响，旨在筛选出可制备富含酚类物质与优质香气活性化合物的葡萄酒的最优工艺条件。本研究优化并验证了顶空固相微萃取-气相色谱-质谱联用（headspace solid phase microextraction and gas chromatography with mass spectrometry, HS-SPME-GC-MS）分析方法，用于41种挥发性成分的检测。主成分分析（PCA）结合方差分析-主成分分析（ANOVA-PCA），并辅以统计学显著载荷值解析，是解析成熟度与浸渍工艺对葡萄酒成分影响的关键分析手段。采用成熟度更高的葡萄（21~23°白利糖度）酿造的葡萄酒，在色泽强度与总酚含量方面表现优异，且富含花青素、黄酮醇、原花青素A2以及具有花香香气的芳樟醇。浸渍时长30天的葡萄酒，其部分黄烷-3-醇类物质、没食子酸、少量果香酯类与醇类物质以及具有花香香气的(E)-橙花叔醇的含量显著提升；而壬酸（带有不愉快香气）的浓度则随浸渍时长延长而降低。