Relationships between volatile compounds and odour in Manchego cheese:: comparison between artisanal and industrial cheeses at different ripening times

Manchego cheese, produced from local ewe's milk in the La Mancha region of Spain under a Protected Designation of Origin (PDO), is Spain's most popular cheese variety and may be made from raw milk (artisanal cheese) or pasteurised milk ( industrial cheese). As a consequence, the cheeses so manufactured may show differences in their organoleptic properties, associated with differences in volatile composition, important for cheese aroma. Samples of Manchego cheese made from raw milk and from pasteurised milk and aged for 2, 4, 6 and 12 months were analysed in this study of the volatile composition of the different cheese types, performed using two different analytical methods, Simultaneous Distillation Extraction (SDE) and Automatic Dynamic Headspace (P&T). Approximately 79 compounds were detected by SDE and 44 by headspace, falling in the chemical groups free fatty acids (FFAs), ketones, esters, alcohols and others. Also, olfactory profiles of the cheese samples were assessed by sensory analysis. Nine odour attributes ( odour intensity, milk odour, lactic/yoghurt odour, briny odour, rancid odour, butter odour, dry hay odour, fruity odour and pungent sensation) were assessed sensorially. Both the concentrations of the volatile compounds detected and the intensity of the sensory odour attributes evaluated were found to vary during ripening. The results were distinctly different for the artisanal and industrial Manchego cheese samples.