Louw Leanie, Roux Karolien, Tredoux Andreas, Tomic Oliver, Naes Tormod, Nieuwoudt Hélène H, van Rensburg Pierre
Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, 7602 Matieland (Stellenbosch), South Africa.
J Agric Food Chem. 2009 Apr 8;57(7):2623-32. doi: 10.1021/jf8037456.
The powerful combination of analytical chemistry and chemometrics and its application to wine analysis provide a way to gain knowledge and insight into the inherent chemical composition of wine and to objectively distinguish between wines. Extensive research programs are focused on the chemical characterization of wine to establish industry benchmarks and authentication systems. The aim of this study was to investigate the volatile composition and mid-infrared spectroscopic profiles of South African young cultivar wines with chemometrics to identify compositional trends and to distinguish between the different cultivars. Data were generated by gas chromatography and FTMIR spectroscopy and investigated by using analysis of variance (ANOVA), principal component analysis (PCA), and linear discriminant analysis (LDA). Significant differences were found in the volatile composition of the cultivar wines, with marked similarities in the composition of Pinotage wines and white wines, specifically for 2-phenylethanol, butyric acid, ethyl acetate, isoamyl acetate, isoamyl alcohol, and isobutyric acid. Of the 26 compounds that were analyzed, 14 had odor activity values of >1. The volatile composition and FTMIR spectra both contributed to the differentiation between the cultivar wines. The best discrimination model between the white wines was based on FTMIR spectra (98.3% correct classification), whereas a combination of spectra and volatile compounds (86.8% correct classification) was best to discriminate between the red wine cultivars.
分析化学与化学计量学的强大结合及其在葡萄酒分析中的应用，为了解葡萄酒的内在化学成分并客观区分不同葡萄酒提供了一种途径。广泛的研究项目聚焦于葡萄酒的化学表征，以建立行业基准和认证体系。本研究的目的是利用化学计量学研究南非年轻品种葡萄酒的挥发性成分和中红外光谱特征，以确定成分趋势并区分不同品种。数据通过气相色谱和傅里叶变换中红外光谱法生成，并采用方差分析（ANOVA）、主成分分析（PCA）和线性判别分析（LDA）进行研究。在品种葡萄酒的挥发性成分中发现了显著差异，皮诺塔吉葡萄酒和白葡萄酒的成分有明显相似之处，特别是对于苯乙醇、丁酸、乙酸乙酯、乙酸异戊酯、异戊醇和异丁酸。在分析的26种化合物中，有14种的气味活性值大于1。挥发性成分和傅里叶变换中红外光谱都有助于区分品种葡萄酒。白葡萄酒之间的最佳判别模型基于傅里叶变换中红外光谱（正确分类率为98.3%），而光谱和挥发性化合物的组合（正确分类率为86.8%）最适合区分红葡萄酒品种。
