title: Does Enzymatic Hydrolysis of Glycosidically Bound Volatile Compounds Really Contribute to the Formation of Volatile Compounds During the Oolong Tea Manufacturing Process?
abstract: It was generally thought that aroma of oolong tea resulted from hydrolysis of glycosidically bound volatiles (GBVs). In this study, most GBVs showed no reduction during the oolong tea manufacturing process. β-Glycosidases either at protein or gene level were not activated during the manufacturing process. Subcellular localization of β-primeverosidase provided evidence that β-primeverosidase was located in the leaf cell wall. The cell wall remained intact during the enzyme-active manufacturing process. After the leaf cell disruption, GBV content was reduced. These findings reveal that, during the enzyme-active process of oolong tea, nondisruption of the leaf cell walls resulted in impossibility of interaction of GBVs and β-glycosidases. Indole, jasmine lactone, and trans-nerolidol were characteristic volatiles produced from the manufacturing process. Interestingly, the contents of the three volatiles was reduced after the leaf cell disruption, suggesting that mechanical damage with the cell disruption, which is similar to black tea manufacturing, did not induce accumulation of the three volatiles. In addition, 11 volatiles with flavor dilution factor ≥4(4) were identified as relatively potent odorants in the oolong tea. These results suggest that enzymatic hydrolysis of GBVs was not involved in the formation of volatiles of oolong tea, and some characteristic volatiles with potent odorants were produced from the manufacturing process.
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.|‡University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China.
authors.forename: Jiadong
authors.initials: J
authors.lastname: Gui
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.|∥Provincial Key Laboratory of Applied Botany South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors.forename: Xiumin
authors.initials: X
authors.lastname: Fu
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.|∥Provincial Key Laboratory of Applied Botany South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: ⊥Tea Research Center, Shizuoka Prefectural Research Institute of Agriculture and Forestry 1706-11 Kurasawa, Kikugawa 439-0002, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Katsuno
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.|∥Provincial Key Laboratory of Applied Botany South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Mei
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors.forename: Rufang
authors.initials: R
authors.lastname: Deng
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors.forename: Xinlan
authors.initials: X
authors.lastname: Xu
authors.affiliation: #College of Horticultural Science, South China Agricultural University, Wushan Road, Tianhe District, Guangzhou 510642, China.
authors.forename: Linyun
authors.initials: L
authors.lastname: Zhang
authors.affiliation: ¶Guangdong Food and Drug Vocational College, Longdongbei Road 321, Tianhe District, Guangzhou 510520, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Dong
authors.affiliation: ○Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561, Japan.
authors.forename: Naoharu
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: †Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.|‡University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, China.|∥Provincial Key Laboratory of Applied Botany South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
authors.forename: Ziyin
authors.initials: Z
authors.lastname: Yang
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D005421:Flavoring Agents / Q000378:metabolism*; D005511:Food Handling; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism; D006868:Hydrolysis; D018515:Plant Leaves / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D055549:Volatile Organic Compounds / Q000378:metabolism*
chemical_list: D005421:Flavoring Agents; D006027:Glycosides; D010940:Plant Proteins; D055549:Volatile Organic Compounds; D006026:Glycoside Hydrolases; C460087:beta-primeverosidase
keywords: aroma; glycosidically bound volatiles; indole; tea; volatile; β-primeverosidase