Volatiles profiling in heated cheese as analyzed using headspace solid-phase microextraction coupled to gas chromatography coupled to mass spectrometry

Cheese is one of the most common fermented dairy foods consumed worldwide. Despite being extensively used, the heating effect on cheese flavor and chemistry has yet to be reported. The impact of heat on cheese aroma profile was assessed using headspace solid-phase microextraction (SPME) coupled to gas chromatography coupled to mass spectrometry (GC-MS). A total of 50 volatiles were identified to encompass fatty acid-derived compounds (82%, 75%, and 87%), nitrogenous (7%, 12%, and 10%), aromatics (6%, 2%, and 0.8%), amino acids derived volatiles (1%, 5%, and 0.7%), sugar derived volatile organic compounds (1%-3%), and terpenes (0.5%-3%) in the heated edam, emmental, and gouda cheese, respectively. The fatty acid-derived volatiles (methyl ketones and fatty acids) are likely to contribute to its flavor amounting to 75%-87% in heated gouda, edam, and emmental cheese aroma profile. Nitrogenous compounds amounted for the second abundant class in all heated cheese at 7%-12% represented by alkyl pyrazines, whereas N-nitrosopiperidine a toxic chemical was found only in heated emmental cheese. This study provides the first approach for the use of cold extraction techniques such as SPME coupled with GC-MS to characterize the aroma profile of three major heated cheese, that is, edam, emmental, and gouda analyzed using chemometric tools in comparison to cold cheese. This study is the first to discuss the generation or not of hazardous compounds (N-nitrosopiperidine) in heated cheese that could negatively affect human health upon consumption.