Aroma Compounds in Japanese Green Tea

Did you know that there are more than 600 volatile compounds in tea?

They are responsible for aroma as well as flavor.

It’s not entirely clear how each compound contributes to the general aroma profile for a given tea.

This isn’t just a matter of adding each aroma and calculating the total.

At different concentrations, the aroma of each compound can change. Plus, it can interact with other aromas, which further complicates things.

For example, Indole has a floral aroma at low concentrations but at higher concentrations it feels like a fecal smell.

Linalool and geraniol have a floral aroma. They are more prevalent in Chinese green teas than in Japanese teas.

Leaf alcohol (cis-3-Hexen-1-ol) is responsible for the fresh aroma of Japanese green teas, especially those from earlier harvests.

Dimethyl sulphide imparts the seaweed aroma to Japanese green tea, and it is found in higher quantities when there is a shading process. A good example is gyokuro.

Pyrazines give houjicha its roasted aroma.

Hydrocarbons

Toluene, C₇H₈ ; Limonene, C₁₀H₁₆ ; ⍺-Cubebene, C₁₅H₂₄ ; ⍺-Copaene, C₁₅H₂₄ ; Caryophyllene, C₁₅H₂₄ ; γ-Muurolene, C₁₅H₂₄ ; ⍺-Muurolene, C₁₅H₂₄ ; δ-Cadinene, C₁₅H₂₄ ; Calamenene, C₁₅H₂₄ ; ⍺-Humulene, C₁₅H₂₄ ; β-Sesquiphellandrene, C₁₅H₂₄

Alcohols

2-Methylpropanol, C₄H₁₀O ; Butanol, C₄H₁₀O ; Furfurylalcohol, C₅H₆O₂ ; 1-Penten-3-ol, C₅H₁₀O ; cis-2-Penten-1-ol, C₅H₁₀O ; 3-Methylbutanol, C₅H₁₂O ; Pentanol, C₅H₁₂O ; cis-3-Hexen-1-ol, C₆H₁₂O ; trans-2-Hexen-1-ol, C₆H₁₂O ; Hexanol, C₆H₁₄O ; Benzyl alcohol, C₇H₈O ; Heptanol, C₇H₁₆O ; 2-Phenylethanol, C₈H₁₀O ; 1-Phenylethanol, C₈H₁₀O ; Octanol, C₈H₁₈O ; Nonanol, C₉H₂₀O ; 3s-( + )-3,7-Dimethyl-1,5,7-octatrien-3-ol, C₁₀H₁₆O ; Linalool, C₁₀H₁₈O ; Nerol, C₁₀H₁₈O ; Geraniol, C₁₀H₁₈O ; ⍺-Terpineol, C₁₀H₁₈O ; Linalool oxide I (cis, furanoid), C₁₀H₁₈O₂ ; Linalool oxide II (trans, furanoid), C₁₀H₁₈O₂ ; Linalool oxide III (liquid, pyranoid), C₁₀H₁₈O₂ ; Linalool oxide IV (solid, pyranoid), C₁₀H₁₈O₂ ; Nerolidol, C₁₅H₂₆O ; ⍺-Cadinol, C₁₅H₂₆O ; Cubenol, C₁₅H₂₆O ; epi-Cubenol, C₁₅H₂₆O

Aldehydes

trans-2-Hexenal, C₆H₁₀O ; 5-Methylfurfural, C₆H₆O₂ ; Benzaldehyde, C₇H₆O ; Heptanal, C₇H₁₄O ; Nonanal, C₉H₁₈O

Ketones

Acetophenone, C₈H₈O ; trans-3,trans-5-Octadien-2-one, C₈H₁₂O ; 6-Methyl-trans,trans-3,5-heptadien-2-one, C₈H₁₂O ; trans-3-Octen-2-one, C₈H₁₄O ; cis-Jasmone, C₁₁H₁₆O ; ⍺-Ionone, C₁₃H₂₀O ; β-Ionone, C₁₃H₂₀O ; Genarylacetone, C₁₃H₂₂O ; 3,4-Dihydro ⍺-ionone, C₁₃H₂₂O ; Theaspirone, C₁₃H₂₀O₂ ; 6,10,14-Trimethylpentadecan-2-one, C₁₈H₃₆O₂

Esters

cis-3-Hexenyl butyrate, C₁₀H₁₈O₂ ; cis-3-Hexenyl trans-2-hexenoate, C₁₂H₂₀O₂ ; Neryl acetate, C₁₂H₂₀O₂ ; ⍺-Terpinyl acetate, C₁₂H₂₀O₂ ; cis-3-Hexenyl hexanoate, C₁₂H₂₂O₂ ; cis-3-Hexenyl benzoate, C₁₃H₁₆O₂ ; Methyl jasmonate, C₁₃H₂₀O₃

Lactones

Coumarin, C₉H₆O₂ ; Jasmine lactone, C₁₀H₁₆O₂ ; Dihydroactinidiolide, C₁₁H₁₆O₂

Acids

Butyric, C₄H₆O₂ ; Pentanoic, C₅H₁₀O₂ ; cis-3-Hexenoic, C₆H₁₀O₂ ; trans-2-Hexenoic, C₆H₁₀O₂ ; Hexanoic, C₆H₁₂O₂ ; Benzoic C₇H₆O₂ ; trans-Geranic, C₁₀H₁₆O₂ ; Decanoic, C₁₀H₂₀O₂

Phenols

Phenol, C₆H₆O ; o-Cresol, C₇H₈O ; m-,p-Cresol, C₇H₈O ; Salicylic acid, C₇H₆O₃ ; Methylsalicylate, C₈H₈O₃ ; 4-Vinylphenol, C₉H₁₀O₂ ; 4-Ethylguaiacol, C₉H₁₂O₂ ; Isoeugenol, C₁₀H₁₂O₂ ; Vanillin, C₈H₈O₃

Miscellaneous oxygenated compounds

1,4-Dimethoxybenzene, C₈H₁₀O₂ ; Anethol, C₁₀H₁₂O

Sulfur compounds

Hydrogen sulfide, H₂S ; Dimethylsulfide, C₂H₆S

Nitrogenous compounds

2-Acetylpyrrole, C₆H₇ON ; 1-Ethyl-2-formylpyrrole, C₇H₉ON ; Indole, C₈H₇N ; Benzylcyanide, C₈H₇N ; 1-Ethyl-2-acetylpyrrole, C₈H₁₁ON ; Diphenylamine, C₁₂H₁₁N

Pyrazines

Methylpyrazine, C₅H₆N₂ ; 2,3-Dimethylpyrazine, C₆H₈N₂ ; 2,5-Dimethylpyrazine, C₆H₈N₂ ; 2,6-Dimethylpyrazine, C₆H₈N₂ ; Ethylpyrazine, C₆H₈N₂ ; 2-Ethyl-3-methylpyrazine, C₇H₁₀N₂ ; 2-Ethyl-5-methylpyrazine, C₇H₁₀N₂ ; 2-Ethyl-6-methylpyrazine, C₇H₁₀N₂ ; Trimethylpyrazine, C₇H₁₀N₂ ; 2,5-Diethylpyrazine, C₈H₁₂N₂ ; 2,6-Diethylpyrazine, C₈H₁₂N₂ ; 3-Ethyl-2,5-dimethylpyrazine, C₈H₁₂N₂ ; Tetramethylpyrazine, C₈H₁₂N₂ ; 2,5-Diethyl-3-methylpyrazine, C₉H₁₄N₂ ; 2,6-Diethyl-3-methylpyrazine, C₉H₁₄N₂ ; 6,7-Dihydro-5H-cyclo-pentapyrazine, C₇H₈N₂ ; 2-Methyl-6,7-dihydro-5H-cyclo-pentapyrazine, C₈H₁₀N₂ ; 5-Methyl-6,7-dihydro-5H-cyclo-pentapyrazine, C₈H₁₀N₂ ; 2-(2′-Furyl)-pyrazine, C₈H₆ON₂ ; 2-(2′-Furyl)-5(or 6)-methylpyrazine, C₉H₈ON₂

Sources:

Tea Aroma Formation

A Comparison of the Volatile Compounds in Several Green Teas

Flavor of green tea