title: Characterisation of odorants in roasted stem tea using gas chromatography-mass spectrometry and gas chromatography-olfactometry analysis.
abstract: Roasted stem tea has a characteristic flavour, which is obtained by roasting tea stems, by-product of green tea production. This research aims to understand the characteristic odorants in roasted stem tea by comparing it to roasted leaf tea. We revealed potent odorants in commercial roasted stem tea using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry with aroma extract dilution analysis (AEDA). The difference between roasted stem and leaf tea derived from the same tea plants were investigated using GC-MS. Pyrazine compounds exhibited a roasted odour and high flavour dilution (FD) factors, as determined via AEDA. Roasted stem tea was richer in these pyrazines than roasted leaf tea. Geraniol and linalool exhibited high FD factors and a floral odour, and roasted stem tea was richer in these compounds than roasted leaf tea. These results may have a positive impact on the development of tea products.
authors.affiliation: Chemistry/Food Department, Industrial Research Institute of Ishikawa, Kanazawa, Ishikawa 920-8203, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Department of Food Science, Ishikawa Prefectural University, Nonoichi, Ishikawa 921-8836, Japan.
authors.forename: Erina
authors.initials: E
authors.lastname: Koshi
authors.affiliation: Chemistry/Food Department, Industrial Research Institute of Ishikawa, Kanazawa, Ishikawa 920-8203, Japan.
authors.forename: Harumi
authors.initials: H
authors.lastname: Take
authors.affiliation: Chemistry/Food Department, Industrial Research Institute of Ishikawa, Kanazawa, Ishikawa 920-8203, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Michihata
authors.affiliation: Maruhachi Seichajo Co., Ltd., Kaga, Ishikawa, 922-0331, Japan.
authors.forename: Masachika
authors.initials: M
authors.lastname: Maruya
authors.affiliation: Department of Food Science, Ishikawa Prefectural University, Nonoichi, Ishikawa 921-8836, Japan. Electronic address: enomoto@ishikawa-pu.ac.jp.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Enomoto
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009812:Odorants / Q000032:analysis*; D064367:Olfactometry / Q000379:methods*; D018547:Plant Stems / Q000737:chemistry; D013662:Tea / Q000737:chemistry*
chemical_list: D013662:Tea
keywords: Gas chromatography-olfactometry; Odorant; Roasted tea; Stem tea