Authenticity of Cypriot sweet wine Commandaria using FT-IR and chemometrics.

UNLABELLED: FT-IR spectra of 65 sweet wines produced in Cyprus and other countries were determined, in order to study the authenticity and uniqueness of the Cypriot traditional wine "Commandaria" that is produced from sun-dried grapes. Different sample preparation methods such as freeze-drying and nitrogen-flow concentration and direct analysis were used. The spectra were obtained in transmittance mode from KBr pellets and by using the attenuated total reflectance technique, and analyzed statistically using multivariate chemometric techniques, involving principal component analysis, cluster analysis, linear and regularized discriminant analysis, and classification and regression trees. A nearly correct classification for Commandaria was achieved. Fourier Transform Infrared spectroscopy and chemometrics were able to differentiate all the types of Commandaria (nonfortified, fortified, and commercial) from various sweet wines from other countries. PRACTICAL APPLICATION: Commandaria is a traditional Cyprus product that was proven to be very popular and economically very important. There is therefore a need to determine its chemical characteristics in order to differentiate it from its competitors and thus enable Cyprus to seek the protection of the name as a regional product. A means of easily distinguishing the genuine product from others mimicking it is also of significant economic interest.