Consonni R, Cagliani L R, Benevelli F, Spraul M, Humpfer E, Stocchero M
Istituto per lo Studio delle Macromolecole, Lab. NMR, CNR, v. Bassini 15, 20133 Milan, Italy.
Anal Chim Acta. 2008 Mar 17;611(1):31-40. doi: 10.1016/j.aca.2008.01.065. Epub 2008 Feb 5.
This work presents the capability of NMR spectroscopy combined with Chemometrics in predicting the ageing of Balsamic and Traditional Balsamic Vinegar of Modena. The need of an analytical method is an important requirement for both research oriented and commercial evaluation of these very valuable products. (1)H NMR spectroscopy, based on the advantage of rapid sample analysis without any manipulation or derivatization, is here proposed as a valid tool to describe Balsamic and Traditional Balsamic Vinegar of Modena. For this purpose, 72 reliable samples, were divided into three different groups according to their ageing process: young (<12 years), old (>12 and <25 years) and extra old (>25 years). Hierarchical Projection to Latent Structures Discriminant Analysis (PLS-DA) allowed us to characterize the ageing process. Variables showing the largest VIP (Variable Importance in the Projection) were extracted from PLS-DA model, thus shedding lights onto the role played by specific compounds in this complex ageing process. Two robust classification models, were built by PLS-DA and Naïve Bayes classifier and compared to prove the accuracy of the representation on both training and test sets. The predictions obtained for 41 "unknown" vinegar samples with these both methods gave more than 80% agreement among them.
这项工作展示了核磁共振光谱法结合化学计量学在预测摩德纳香醋和传统摩德纳香醋陈酿情况方面的能力。对于这些极具价值的产品，无论是面向研究还是商业评估，都迫切需要一种分析方法。基于无需任何样品处理或衍生化即可快速进行样品分析的优势，¹H核磁共振光谱法在此被提议作为一种描述摩德纳香醋和传统摩德纳香醋的有效工具。为此，72个可靠样品根据其陈酿过程被分为三个不同组：年轻的（<12年）、陈年的（>12年且<25年）和特级陈年的（>25年）。潜在结构判别分析的层次投影法（PLS-DA）使我们能够表征陈酿过程。从PLS-DA模型中提取显示出最大VIP（投影中变量重要性）的变量，从而揭示特定化合物在这一复杂陈酿过程中所起的作用。通过PLS-DA和朴素贝叶斯分类器构建了两个稳健的分类模型，并进行比较以证明在训练集和测试集上表示的准确性。用这两种方法对41个“未知”醋样品进行预测，结果显示它们之间的一致性超过80%。
