Aroma active compounds of bulgogi

Volatile components in bulgogi were extracted by high vacuum sublimation (HVS) and solid phase microextraction (SPME). The extracts were then analyzed by gas chromatography-olfactometry (GCO) conducted on 2 columns with different polarities. Aroma dilution methods were used with a serial dilution of the extract in HVS-GCO and varying the GC injector split ratios in SPME-GCO to determine aroma active compounds of bulgogi. In HVS-GCO, methional (described as cooked potato/soy sauce) exhibited the highest flavor dilution (FD) factor, followed by 2-acetyl-2-thiazoline (described as nutty/popcorn/peanut), furaneol (described as caramel/sweet), and 2-ethyl-3,5-dimethylpyrazine (described as nutty/coffee/chocolate). In SPME-GCO, allyl mercaptan (described as garlic/bulgogi) showed the highest FD factor, followed by methional (described as cooked potato/soy sauce), 2-ethyl-3,5-dimethylpyrazine (described as nutty/coffee/chocolate), and 2-acetylpyrazine (described as nutty/peanut/cooked rice). These sulfur-containing compounds and heterocyclic compounds, which had high FD factors and characteristic odor notes, could be important to bulgogi flavor.