Aroma-active compounds in Kimchi during fermentation

During fermentation, volatile flavor compounds in Kimchi prepared with (FS) and without (C) fish sauce were analyzed by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry (V-SDE/GC/MS) and GC/olfactometry. On the basis of their high odor intensities (OI greater than or equal to 3), eight sulfur-containing compounds having garlic-, garlic salt-, onion-, green onion-, and cooked cabbage-like odors and six unknowns with garlic-, onion-, and green onion-like odors were predominant in both FS and C during fermentation. The most intense odorants (OI greater than or equal to 4.0) in Kimchi included dimethyl trisulfide, diallyl disulfide isomers, diallyl trisulfide, methylallyl disulfide, and an unknown (garlic salt-and/or mustard-like). In addition to these, other odorants (OI greater than or equal to 3.5) such as 3-(methylthio)propanal (baked/boiled potato-like), (E,Z)-2,6-nonadienal (cucumber-like), phenylacetaldehyde (honeysuckle-like), linalool (floral-and/or flower-like), (E,E)-2,4-decadienal (fatty and/or sweet), 2,3-butanedione (buttery), unknown (meaty), unknown (apple sauce-like), and unknown (vitamin and/or cooked rice-like) may play important roles in formation of Kimchi flavor. Addition of fish sauce did not noticeably affect the aroma profile of Kimchi.