title: Characterisation of odorant compounds and their biochemical formation in green tea with a low temperature storage process.
abstract: We produced low temperature (15 °C) processed green tea (LTPGT) with higher aroma contents than normal green tea (Sencha). Normal temperature processed green tea (NTPGT), involved storing at 25 °C, and Sencha had no storing process. Sensory evaluation showed LTPGT had higher levels of floral and sweet odorants than NTPGT and Sencha. Aroma extract dilution analysis and gas chromatography-mass spectrometry-olfactometry indicated LTPGT had 12 aroma compounds with high factor dilution values (FD). Amongst LTPGT's 12 compounds, indole, jasmine lactone, cis-jasmone, coumarin, and methyl epijasmonate contributed to floral, fruity and sweet characters. In particular, indole increased initially, peaking at 16 h, then gradually decreased. Feeding experiments suggested [(15)N]indole and [(15)N]oxygenated indoles (OX-indoles) were produced from [(15)N]anthranilic acid. We proposed the increase in indole was due to transformation of anthranilic acid during the 16 h storage and the subsequent decline in indole level was due to its conversion to OX-indoles.
authors.affiliation: Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561, Japan; Shizuoka Prefectural Research Institute of Agriculture and Forestry, Tea Research Center, 1709-11 Kurasawa, Kikugawa, Shizuoka 439-0002, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Katsuno
authors.forename: Hisae
authors.initials: H
authors.lastname: Kasuga
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kusano
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yaguchi
authors.forename: Miho
authors.initials: M
authors.lastname: Tomomura
authors.forename: Jilai
authors.initials: J
authors.lastname: Cui
authors.forename: Ziyin
authors.initials: Z
authors.lastname: Yang
authors.forename: Susanne
authors.initials: S
authors.lastname: Baldermann
authors.forename: Yoriyuki
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Mase
authors.forename: Naoharu
authors.initials: N
authors.lastname: Watanabe
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry*; D061353:Food Storage; D008401:Gas Chromatography-Mass Spectrometry; D009812:Odorants / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry*; D013662:Tea / Q000737:chemistry*; D013696:Temperature
chemical_list: D010936:Plant Extracts; D013662:Tea
keywords: AEDA; Camellia sinensis; ESI; FD; GC–MS/O; HIPV; HR-MS; Indole; LTPGT; Metabolome analysis; NTPGT; Odorant compounds; Tea leaves; [(15)N]Anthranilic acid; [(15)N]Indole; aroma extraction and dilution analysis; electrospray ionisation; factor of dilution value; gas chromatography–mass spectroscopy–olfactometry determination; herbivore-induced plant volatiles; high resolution mass spectroscopy; low temperature processed green tea; normal temperature processed green tea