NMR-based metabolomics has been extensively used for the classification of wine samples according to their geographical origin, and several studies have shown a clear differentiation among wine samples produced by grapes belonging to the same cultivar but harvested in different regions of the same country.
Our novel method is a trial of realizing an engineering model of the sensing and recognizing systems of humans that combines all features of artificial olfactory and artificial taste, i.e. 'electronic nose' and 'electronic tongue' for the classification of wine.
This motivation spawned a new classification of wine in Italy.
Figure 7 presents PCA (A) and OPLS-DA (B) score plots of healthy and botrytized base wines indicating the correct classification of healthy wines and wines infected by Botrytis cinerea (20 and 40% of infection).
(Extra bonus points here for anyone who wants to compare the mid-nineteenth-century classification of French wine, which only happened in 1855, with the companion classification of dogs around the same time.
The organic compounds that were responsible for the classification of the wine samples according to vintage were mainly amino acids, sugars, and aromatic compounds [11].
The data obtained were treated using advanced chemometric tools like Principal Component Analysis (PCA) and Soft Independent Modeling Class Analogy (SIMCA) for the classification of the wine mixtures and Partial Least Squares (PLS) regression for the quantification of the grape variety composition.
PLS-DA models of the obtained metabolomic data showed good differentiation of the wine samples according to their geographical origin, with total acidity, citric acid, malic acid, succinic acid, lactic acid, total polyphenol index, glucose, and proline/arginine ratio being the main contributors to the classification of the wine samples [62].
At the third level of classification are wines sold under the simple village appellations.
1H NMR spectroscopy combined with multivariate statistical analysis showed classification of two vintages (2008 and 2009) of wines produced in Germany from different grape varieties, by different enological technologies and from different producing areas [55].
