15A-4 |
Flavor characteristics of volatile compounds from suspension culture of Agastache rugosa Kuntze (Korean mint) cells |
T. H. KIM1, J. H. Shin1, H. H. Baek2, and H. J. Lee1. (1) Dept. of Food Science & Technology, Seoul National Univ., School of Agricultural Biotechnology, Suwon, 441-744, South Korea, (2) Dept. of Food Engineering, Dankook Univ., Chunan, 330-714, South Korea Agastache rugosa Kuntze (Korean mint), an aromatic plant native to Korea, China, and Japan, has been used as a culinary herb and a remedy for colds for a long time. Plant cell culture has been applied for the production of secondary metabolites such as colorants, flavors, and pharmaceuticals. The most abundant volatile compounds of A. rugosa were reported as methylchavicol, limonene, and eugenol. A. rugosa could be utilized as a good source of flavorings but cell culture of the plant has not been tried. Our objective was to elucidate flavor characteristics of volatile compounds from A. rugosa suspension culture as a way of biotechnological production of flavorings. A. rugosa suspension culture was maintained in Murashige and Skoog medium supplemented with 50 g/l sucrose and 1 mg/l 2,4-dichlorophenoxyacetic acid. Volatiles were isolated from a 15-day-old cell-free suspension culture by liquid-liquid continuous extraction, and identified by gas chromatography/mass spectrometry/olfactometry (GC/MS/O). For studying the time course of flavor production, volatiles of cell-free suspension harvested every four days were obtained by direct solvent extraction. In GC/MS, 26 volatile compounds were identified, however, the profiles were quite different from that of native plant. 3-Hydroxy-2-butanone was the most abundant compound in suspension culture, followed by 2,4,5-trimethyl-3-oxazoline, 1,2,4-trimethylbenzene, and 1,3-butanediol. The most potent aroma-active compounds of the culture were 2,3-butanedione (buttery/cheese), (E,Z)-2,6-nonadienal (cucumber/melon), and (E,Z)-2,6-nonadien-1-ol (cucumber/sweet). In the time course study, A. rugosa suspension culture exhibited the inverse relationship between cell growth and flavor production, and flavor characteristics changed from buttery to buttery/cucumber/wine-like aroma, in the stationary phase. These results suggest that suspension culture of A. rugosa cells could be developed for flavor production although the flavor characteristics was different from the original plant. This may be due to the undifferentiation of cells into specific tissue that is essential for accumulating flavor compounds.
Session 15A, Biotechnology
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