Use of a non-destructive sampling method for characterization of Iberian cured ham breed and feeding regime using GC-IMS

Iberian cured ham from purebred pigs fattened on grazing acorns is a highly appreciated product. There are several analytical methods to avoid its labelling fraud; however, these require opening the ham. The aim of this work is testing a non-destructive sampling method which does not spoil the physical integrity of the ham. It consists of a puncture with a needle imitating a traditional olfactory system. After removing the needle impregnated with fat, its volatiles are analyzed with a Gas Chromatography (GC) coupled to Ion Mobility Spectrometry (IMS). The potential of this methodology was studied analyzing 156 Iberian hams from pigs under two different feeding regimes (acorns versus feed) and from different breed (Iberian versus Duroc crossed). Intensity of GC-IMS plot features was extracted and chemometric differentiation models were obtained; one for feeding regime and another for breed, providing validated classification rates of 91.7% and 100%, respectively. In addition, 29 features used for construction of both models were tentatively identified using chemical standards. The suitability of the method for quality control analysis was characterized by means of a precision study. As a conclusion, GC-IMS becomes a useful tool to guarantee dry-cured Iberian ham authenticity and detect labelling fraud.