Chemical Characterization of Calvados (Apple Brandy) Young Spirits: Separation of Polar and Non-Polar Volatile Compounds

Calvados is an apple-brandy of Normandy (France). Mashed apples are fermented to obtain cider and then distilled to give the young spirit.

Spirit aromas are a subtle balance of various volatile compounds belonging to different chemical classes, having different chemical functionalities and consequently various polarities. They may be acetals, aldehydes, alcohols, carboxylic acids, ketones and phenolic derivatives. In Calvados, esters with fruity descriptors are believed to improve the quality, while carboxylic acids with "rancid, sweat" notes are supposed to decrease the quality.

The aromatic composition can be determined using two techniques, gas chromatography coupled to mass spectrometry (GC–MS) to determine the volatile composition and gas chromatography coupled to olfactometry (GC–O) to determine the corresponding odours.

The GC analysis is typically performed using both a non-polar phase (such as 5% phenyl polysiloxane) and a polar phase (such as a polyethylene glycol) for the separation. In the work reported here, a medium polar phase [14% cyanopropylphenyl polysiloxane (BP10)] was used, as it was found to separate both volatile and semi-volatile compounds (such as a non-polar phase), and polar compounds of close molecular weights (such as a polar phase).

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