Volatile profile of Stilton cheeses: Differences between zones within a cheese and dairies

Penicillium roqueforti grows and sporulates during the ripening period of blue cheeses and it is responsible for the typical blue cheese flavour formation. However, the sporulation (blue veins) is taking place in a fraction of the total mass and the cheese matrix is highly heterogeneous. The aroma profiles regarding the three different sections of Stilton cheese, blue veins outer crust and white core, were studied using solvent extraction GC–MS, a headspace GC–MS technique (SPME GC–MS) and direct headspace analysis (APCI–MS). Cheeses from different dairies were analysed, allowing the question of how similar are different batches of cheese from different dairies. APCI–MS was good for rapid discrimination of the different cheese profiles. However, the analysis was affected by the presence of ammonia in the headspace. SPME GC–MS produced a large amount of information for screening differences between the sections of the cheese and dairies. Overall, the blue and the outer crust had similar profiles. These two sections contained the higher amount of ketones, while the white contained higher amounts of alcohols and aldehydes.