title: Identification of potent odorants in different green tea varieties using flavor dilution technique.
abstract: Two kinds of pan-fired green teas (Japanese Kamairi-cha and Chinese Longing tea) were compared with the common Japanese green tea (Sen-cha). Application of the aroma extract dilution analysis (AEDA) using the volatile fraction of the Sen-cha, Kamairi-cha and Longing tea infusions revealed 32, 51, and 52 odor-active peaks with flavor dilution factors between 16 and 1024, respectively. (Z)-1,5-Octadien-3-one (metallic, geranium-like), 4-mercapto-4-methyl-2-pentanone (meaty, black currant-like), methional (potato-like), (E,Z)-2,6-nonadienal (cucumber-like), and 3-methylnonane-2,4-dione (green, fruity, hay-like) showed high flavor dilution factors in all varieties. In addition, 2-acetyl-1-pyrroline (popcorn-like), 2-ethyl-3,5-dimethylpyrazine (nutty), 2,3-diethyl-5-methylpyrazine (nutty), and 2-acetyl-2-thiazoline (popcorn-like) belonged to the most potent odorants only in the pan-fired green teas. Among these odorants, 2-acetyl-1-pyrroline and 2-acetyl-2-thiazoline were identified for the first time among the tea volatiles.
authors.affiliation: Material Research and Development Laboratories, Ogawa & Company, Ltd., 15-7 Chidori Urayasushi, Chiba 279-0032, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kumazawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Masuda
mesh_terms: D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007201:Indicator Dilution Techniques; D009812:Odorants / Q000032:analysis*; D011758:Pyrroles / Q000032:analysis; D012903:Smell; D013662:Tea / Q000737:chemistry*; D013844:Thiazoles / Q000032:analysis; D014835:Volatilization
chemical_list: D011758:Pyrroles; D013662:Tea; D013844:Thiazoles; C426303:2-acetyl-1-pyrroline; C455104:2-acetyl-2-thiazoline