Abstract: In this study, four domestic hawthorn kernel liquid smokes: I, II, II-2002 and II-2003 and five liquid smokes produced by Red Arrow (USA): Smokez poly C-10-03, C-10-05, C-10-10, C-10-11, and C-10-22 were evaluated and compared for their flavor components using electronic nose and electronic tongue technology combined with gas chromatography-mass spectrometry (GC-MS). The results of electronic nose showed discrimination of the domestic liquid smokes from the imported ones, which had similarity in flavor. Principal component analysis performed on the electronic tongue data revealed that there were differences in overall taste profile among all liquid smokes except for oil-soluble C-10-11 and C-10-22, and C-10-03 and C-10-10 were mainly affected by salty taste while the five others were affected by salty taste, bitterness and astringency and richness. Besides, liquid smoke I was also affected by sourness. A total of 156 flavor compounds, including ketones, phenols, acids, aldehydes, alcohols, esters, nitrogen and other compounds, were identified by GC-MS. Ketones were dominant, followed by phenols and acids. Finally, a comprehensive evaluation model for the flavor of liquid smokes was obtained by principal component analysis. The comprehensive flavor scores of the nine liquid smokes were in the following decreasing order: C-10-05, C-10-10, C-10-03, C-10-11, C-10-22, II, II-2002, I, and II-2003, revealing the difference in flavor between hawthorn kernel liquid smokes and Red Arrow-produced liquid smokes.

Key words: liquid smoke; electronic nose; electronic tongue; gas chromatography-mass spectrometry; flavor