Abstract:  A total of 45 and 41 compounds were detected in white grapefruit juice and red grapefruit juice with total relative contents of 84.43% and 89.16% by solid phase microextraction coupled with gas chromatography-mass spectrometry, respectively. Meanwhile, 20 and 21 aromatic compounds were also identified in both kinds of juice by GC-Olfactometry. The 3-hydroxyl ethyl butyrate, geranyl acetate and RI = 1006 (piney, fresh and fruity) were the major aroma compounds in white grapefruit juice. The compounds with strong aromatic intensity were 2-methyl ethyl propionate, 2-methyl ethyl butyrate, trans-2-hexene-1-ol, heptanal, 1-octen-3-ol, α-terpinene, 3-hydroxyl ethyl hexanoate, carvone and three unknown compounds (RI = 971, 1156 and 1390) in red grapefruit juice. The odor profile showed that white grapefruit juice and red grapefruit juice mainly presented as fruity odor and wood/leaf odor, respectively.

Key words: grapefruit juice, aroma, GC-Olfactometry, SPME