Effect of the pig rearing system on the final volatile profile of Iberian dry-cured ham as detected by PTR-ToF-MS

The volatile compound profile of dry-cured Iberian ham lean and subcutaneous fat from pigs fattened outdoors on acorn and pasture (Montanera) or on high-oleic concentrated feed (Campo) was investigated by proton transfer reaction time-of-flight mass spectrometry. In addition to the usual proton transfer ionization the novel switchable reagent ions system was implemented which allows the use of different precursor ions (H3O+, NO+ and O2+). The analysis of the lean and subcutaneous fat volatile compounds allowed a good sample discrimination according to the diet. Differences were evident for several classes of compounds: in particular, Montanera hams showed higher concentrations of aldehydes and ketones and lower concentrations of sulfur-containing compounds compared to Campo hams. The use of NO+ as precursor ion confirmed the results obtained with H3O+ in terms of classification capability and provides additional analytical insights.

► The effect of rearing system on the volatile profile of Iberian ham was studied. ► A rapid and non-destructive PTR-ToF-MS profiling and a novel SRI system were used. ► Classification model was set with high success rate: the diet has a strong effect. ► The SRI system improve the analytical capability of PTR-MS. ► PTR-ToF-MS allows the rapid characterisation of food samples and ham in particular.