Aroma active compounds of Bulgogi extracted by high vacuum sublimation

Abstract

Volatile flavor components of bulgogi, broiled beef with its unique sauce, were analyzed through high vacuum sublimation-gas chromatography-mass spectrometry-olfactometry (HVS-GC-MS-O). Among 60 volatile compounds identified by GC-MS, -caryophyllene was the most abundant, followed by diallyl disulfide, -phellandrene, acetic acid, and 2-hydroxy-2-butanone. Thirty-two aroma active compounds were detected by HVS-GC-O conducted on two GC columns of different polarity (DB-5ms and DB-Wax). The most potent aroma active compounds were methional (described as boiled potato-like/soy sauce-like), furaneol (described as caramel-like/sweet), 2- ethyl-3,5-dimethylpyrazine (described as coffee-like/nutty/toasted laver-like), 2-acetyl-2- thiazoline (described as nutty/popcorn-like/peanut-like) and 3-isobutyl-2-methoxy pyrazine (described as bell pepper-like/metallic/earthy) . The odor threshold values of potent aroma compounds were also determined by paired comparison test. Odor threshold values of potent aroma active compounds were as follows : methional (0.08㎍/L), furaneol (6.25㎍/L), 2-ethyl-3,5- dimethylpyrazine (1.56㎍/L), 3-isobutyl-2-methoxy pyrazine (0.31㎍/L), 1-octen-3-one (50㎍/L), 2-acetylpyrazine (12.5㎍/L), linalool (89.4㎍/L) , phenylacetaldehyde (78.23㎍/L) , and allylmercaptan (0.32㎍/L). Although most of potent aroma active compounds in bulgogi had high FD factor, they were not detected by GC/MS except for 2-ethyl-3,5-dimethylpyrazine, linalool, and phenylacetaldehyde. These results were strongly related to low odor threshold values.