Volatile compounds in sea mustard, Undaria pinnatifida

The volatile compounds of sea mustards (Undaria pinnatifida) cultured in different places (Wando, Jindo, Kijang, and Youngduk) and natural sea mustard harvested in Ullungdo were investigated. Samples were extracted by simultaneous steam distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry. A total of 127 compounds were identified in the five sea mustards. Sea mustards cultured in Wando, Jindo, Kijang, and Youngduk had total of 125, 126, 123, and 123 volatile compounds, respectively. Natural sea mustard (Ullungdo) had 122 volatile components. Out of 127 compounds, 71 compounds were positively identified. These included 4 acids, 34 aldehydes, 19 alcohols, 34 ketones, 8 esters, 12 hydrocarbons, 5 sulfur-containing compounds, and 11 miscellaneous. The amount of common compounds was generally higher in Wando sea mustards than in the others. The patterns of total ion chromatogram were similar between the Wando and Jindo, and the Kijang and Youngduk sea mustards. The flavors of the sea mustards were most likely determined by the presence of a large number of aldehydes and ketones. Many of the compounds identified in this study probably originate from thermal degradation and/or thermal interactions among the constituents in sea mustards during steam distillation.