title: Green tea flavour determinants and their changes over manufacturing processes.
abstract: Flavour determinants in tea infusions and their changes during manufacturing processes were studied using Camellia sinensis cultivars 'Bai-Sang Cha' ('BAS') possessing significant floral scents and 'Fuding-Dabai Cha' ('FUD') with common green tea odour. Metabolite profiling based on odour activity threshold revealed that 'BAS' contained higher levels of the active odorants β-ionone, linalool and its two oxides, geraniol, epoxylinalool, decanal and taste determinant catechins than 'FUD' (p<0.05). Enhanced transcription of some terpenoid and catechin biosynthetic genes in 'BAS' suggested genetically enhanced production of those flavour compounds. Due to manufacturing processes, the levels of linalool and geraniol decreased whereas those of β-ionone, linalool oxides, indole and cis-jasmone increased. Compared with pan-fire treatment, steam treatment reduced the levels of catechins and proportion of geraniol, linalool and its derivatives, consequently, reducing catechin-related astringency and monoterpenol-related floral scent. Our study suggests that flavour determinant targeted modulation could be made through genotype and manufacturing improvements.
authors.affiliation: State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, China.
authors.forename: Zhuo-Xiao
authors.initials: ZX
authors.lastname: Han
authors.affiliation: State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, China; Bangladesh Tea Research Institute, Srimangal-3210, Moulvibazar, Bangladesh.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Rana
authors.affiliation: State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, China.
authors.forename: Guo-Feng
authors.initials: GF
authors.lastname: Liu
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon Research and Development Centre, Saskatoon, Saskatchewan S7N 0X2, Canada.
authors.forename: Ming-Jun
authors.initials: MJ
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, China.
authors.forename: Da-Xiang
authors.initials: DX
authors.lastname: Li
authors.affiliation: Tea Company of September 16, Shucheng, Anhui 231334, China.
authors.forename: Fu-Guang
authors.initials: FG
authors.lastname: Wu
authors.affiliation: Tea Company of September 16, Shucheng, Anhui 231334, China.
authors.forename: Xin-Bao
authors.initials: XB
authors.lastname: Li
authors.affiliation: State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, China.
authors.forename: Xiao-Chun
authors.initials: XC
authors.lastname: Wan
authors.affiliation: State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, China. Electronic address: weishu@ahau.edu.cn.
authors.forename: Shu
authors.initials: S
authors.lastname: Wei
mesh_terms: D000080462:Acyclic Monoterpenes; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical; D005421:Flavoring Agents / Q000737:chemistry*; D039821:Monoterpenes / Q000378:metabolism*; D009812:Odorants / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry*; D013649:Taste; D013662:Tea / Q000737:chemistry*
chemical_list: D000080462:Acyclic Monoterpenes; D005421:Flavoring Agents; D039821:Monoterpenes; D010936:Plant Extracts; D013662:Tea; D002392:Catechin; C018584:linalool
keywords: Caffeine; Camellia sinensis; Catechins; Gene expression; Manufacturing process; Tea flavour; Volatile profiles