Camellia sinensis (L.) O.Kuntze - syn.Thea sinensis L. - Theaceae - tea, Teestrauch
Evergreen shrub (3-4m) or small tree (to 10m), in culture 1.5-2m, native to South China and India, cultivated in Southeast Asia, East Africa, South America; leaves alternate, dark green, elliptic-cuneate, leathery, serrulate; flowers fragrant, wheel-shaped, white or pink, solitary or little groups forming.
„Two major varieties are grown: Camellia sinensis var. sinensis for Chinese teas, and Camellia sinensis var. assamica for Indian Assam teas. White tea, yellow tea, green tea, oolong, pu-erh tea and black tea are all harvested from one or the other, but are processed differently to attain varying levels of oxidation.“
Camellia sinensis var.assamica = Camellia assamica (Mast.) Hung T.Chang; Camellia theifera Griff. - Assam tea
Camellia sinensis var.sinensis = Camellia thea Link; Thea sinensis L. (var. parvifolia Miq.) - Chinese tea
„Aroma extract dilution analysis (AEDA) of the volatile fractions of green and black tea samples revealed 28 odourants of which 27 were identified. As the odour quality and the chromatographic properties of most of the odourants occurring in the air above the tea powders agreed with those which were identified by the preceding AEDA, these compounds were detectable by gas chromatography–olfactometry (GC–O) in static headspace samples. (Z)-Hex-3-enal, linalool, (Z)-octa-1,5-dien-3-one, oct-1-en-3-one, (Z)-hept-4-enal, butane-2,3-dione, 2-methylpropanal, 3-methylbutanal, 3-methylnonane-2,4-dione, (E)-non-2-enal, octanal, (E,Z)-nona-2,6-dienal and hexanal were found in the headspace volume of 40 ml which was drawn at 40°C from both kinds of tea. (E,E)-Nona-2,4-dienal and α-pinene were detected as additional odourants of black tea. The most potent odourants occurring in the air above the tea powders were evaluated by the analysis of decreasing headspace volumes, e.g. (Z)-hex-3-enal was the sole odourant in 2 ml of the headspace of green tea and linalool in 0.5 ml of that of black tea. This procedure indicated that the difference in the odours of green and black tea was mainly due to a higher concentration of (Z)-hex-3-enal, (Z)-octa-1,5-dien-3-one and butane-2,3-dione and the much lower concentration of linalool in the air above the former.“
[Identification of potent odourants in static headspace samples of green and black tea powders on the basis of aroma extract dilution analysis (AEDA)., H. Guth, W. Grosch, Flavour and Fragrance Journal, Vol.8, 1993, 4]
Of the 36 odor-active (shown by AEDA) compounds of a Japanese green tea (Sen-cha), 4-methoxy-2-methyl-2-butanethiol (meaty), (Z)-1,5-octadien-3-one (metallic), 4-mercapto-4-methyl-2-pentanone (meaty), (E,E)-2,4-decadienal (fatty), β-damascone (honey-like), β-damascenone (honey-like), (Z)-methyl jasmonate (floral), and indole (animal-like) showed the highest FD factors (the most important components of the Japanese green tea odor). Newly identified compounds in green tea were 4-methoxy-2-methyl-2-butanethiol, 4-mercapto-4-methyl-2-pentanone, methional, 2-ethyl-3,5-dimethylpyrazine, (Z)-4-decenal, β-damascone, maltol, 5-octanolide, 2-methoxy-4-vinylphenol, and 2-aminoacetophenone.
[Kumazawa, Kenji, and Hideki Masuda. „Identification of potent odorants in Japanese green tea (Sen-cha).“ Journal of agricultural and food chemistry 47.12 (1999): 5169-5172]
„Two kinds of pan-fired green teas (Japanese Kamairi-cha and Chinese Longing tea) were compared with the common Japanese green tea (Sen-cha). Application of the aroma extract dilution analysis (AEDA) using the volatile fraction of the Sen-cha, Kamairi-cha and Longing tea infusions revealed 32, 51, and 52 odor-active peaks with flavor dilution factors between 16 and 1024, respectively. (Z)-1,5-Octadien-3-one (metallic, geranium-like), 4-mercapto-4-methyl-2-pentanone (meaty, black currant-like), methional (potato-like), (E,Z)-2,6-nonadienal (cucumber-like), and 3-methylnonane-2,4-dione (green, fruity, hay-like) showed high flavor dilution factors in all varieties. In addition, 2-acetyl-1-pyrroline (popcorn-like), 2-ethyl-3,5-dimethylpyrazine (nutty), 2,3-diethyl-5-methylpyrazine (nutty), and 2-acetyl-2-thiazoline (popcorn-like) belonged to the most potent odorants only in the pan-fired green teas.“
[Identification of potent odorants in different green tea varieties using flavor dilution technique., Kumazawa, K., Masuda, H., Journal of agricultural and food chemistry, 50(20), 2002, 5660-5663]
„By application of the aroma extract dilution analysis on the volatile fraction isolated from a black tea infusion (Darjeeling Gold Selection), vanillin (vanilla-like), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel), 2-phenylethanol (flowery), and (E,E,Z)-2,4,6-nonatrienal (oat-flake-like) were identified with the highest flavor dilution (FD) factors among the 24 odor-active compounds detected in the FD factor range of 4−128. Quantitative measurements performed by means of stable isotope dilution assays and a calculation of odor activity values (OAVs; ratio of concentration to odor threshold in water) revealed, in particular, the previously unknown tea constituent (E,E,Z)-2,4,6-nonatrienal as a key odorant in the infusion and confirmed the important role of linalool and geraniol for the tea aroma. An aroma recombinate performed by the 18 odorants for which OAVs > 1 were determined in their “natural” concentrations matched the overall aroma of the tea beverage. In the black tea leaves, a total of 42 odorants were identified, most of which were identical with those in the beverage prepared thereof. However, quantitative measurements indicated that, in particular, geraniol, but also eight further odorants were significantly increased in the infusion as compared to their concentration in the leaves.“
[Characterization of the key aroma compounds in the beverage prepared from Darjeeling black tea: quantitative differences between tea leaves and infusion., Schuh, C., Schieberle, P., Journal of agricultural and food chemistry, 54(3), 2006, 916-924]
„The volatile constituents of two exquisite green tea varieties, Kiyosawa tea from Japan and Long Jing tea from China, were investigated in order to identify new compounds responsible for the characteristic flavor of a green tea brew. The extracts were prepared by solid-phase extraction using Oasis-HLB-cartridges. Besides the common compounds of green tea chemistry, the already described compounds 3-methyl-2,4-nonanedione (1) and 3-hydroxy-3-methyl-2,4-nonanedione (2), products of degradation of furan fatty acids, as well as three new compounds related to compound 1 were identified. These were 1-methyl-2-oxopropyl hexanoate (3), 1-methyl-2-oxoheptyl acetate (4) and 2-butyl-4,5-dimethyl-3(2H)-furanone (5). Their syntheses and spectroscopic data are reported. Compound 2 increases the sweet, creamy aroma and the characteristic mouthfeel of a green tea flavor, compounds 3 and 4 contribute to its floral, juicy notes and compound 5 exhibits an interesting sweet, buttery flavor.“
[New constituents related to 3-methyl-2,4-nonanedione identified in green tea., Naef, R., Jaquier, A., Velluz, A., Maurer, B., Journal of agricultural and food chemistry, 54(24), 2006, 9201-9205]
Potent odorants of black tea are aldehydes like 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, (E)-2-hexenal, (z)-4-heptenal, (E)-2-nonenal, (E,Z)-2,6-nonadienal, (E,E)-2,4-nonadienal, (E,E)-decadienal,and (E,E,Z)-2,4,6-nonatrienal, alcohols like (Z)-3-hexene-1-ol, linalool, and geraniol, as well as phenylacetaldehyde, 3-methyl-2,4-nonandione, (E)-β-damascenone, β-ionone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 4-hydroxy-4,5-dimethyl-2(5H)-furanone.
The lipid oxidation products play an important role for black tea aroma, but are more important for green tea. (Z)-hex-3-enal, (Z)-octa-1,5-dien-3-one, and 3-methyl-2,4-nonandione are responsible for the green and hay-like odor notes of green tea.
[Lehrbuch der Lebensmittelchemie, Belitz, H.D., Grosch, W., Schieberle, P., Berlin Heidelberg New York, 2007, 987]
„We investigated the effects of the odor of jasmine tea on autonomic nerve activity and mood states in a total of 24 healthy volunteers. We used the odor of jasmine tea at the lowest concentration that could be detected by each subject but that did not elicit any psychological effects. R-R intervals and the POMS test were measured before and after inhalation of the odors for 5 min. Both jasmine tea and lavender odors at perceived similar intensity caused significant decreases in heart rate and significant increases in spectral integrated values at high-frequency component in comparison with the control (P < 0.05). In the POMS tests, these odors produced calm and vigorous mood states. We also examined the effects of (R)-(-)-linalool, one of its major odor components, at the same concentration as in the tea, and (S)-(+)-linalool. Only (R)-(-)-linalool elicited a significant decrease in heart rate (P < 0.05) and an increase in high-frequency component in comparison with the controls, and produced calm and vigorous mood states. Thus, the low intensity of jasmine tea odor has sedative effects on both autonomic nerve activity and mood states, and (R)-(−)-linalool, one of its components, can mimic these effects.“
[Sedative effects of the jasmine tea odor and (R)-(-)-linalool, one of its major odor components, on autonomic nerve activity and mood states., Kuroda, K., Inoue, N., Ito, Y., Kubota, K., Sugimoto, A., Kakuda, T., Fushiki, T., European journal of applied physiology, 95(2-3), 2005, 107-114]
The high-impact chemical 3-sulfanylhexan-1-ol, with its unique scent of grapefruit and tropical fruits, is also an important trace constituent of very costly 'white teas'.
[Meaningful Scents around the World, R.Kaiser, 2006, 69]
The volatile flavour components of different teas (Green Assam tea, Four Season tea, Chin Shin Oolong tea, Chin Hsuan Oolong tea, Green Oolong tea) from Thailand were extracted using the simultaneous distillation and extraction (SDE) technique in low percentage yield (0.01-0.03% w/w). Important components of tea essential oils were:
Green Oolong - hotrienol, geraniol, linalool, α-terpineol, coumaran, nerol, β-ionone, and indole.
Green Assam - linalool, geraniol, α-terpineol, nerol, benzyl acetate, phytol, β-ionone, hotrienol, and (E)-nerolidol.
Chin Shin Oolong - linalool, indole, (Z)-jasmone, (E)-nerolidol, hotrienol, α-terpineol, methyl jasmonate, and acetophenone.
Chin Hsuan Oolong - (E)-nerolidol, (Z)-jasmone, geraniol, hotrienol, linalool, trans-linalyl oxide (pyranoid), and β-ionone.
Four Season - indole, geraniol, (Z)-jasmone, methyl jasmonate, α-terpineol, hotrienol, and β-ionone.
[Fingerprint of volatile flavour constituents and antioxidant activities of teas from Thailand., Pripdeevech, P., Machan, T., Food Chemistry, 125(2), 2011, 797-802]
„Monomeric flavonoids (flavan 3-ols or tea catechins) present in Camellia sinensis leaf are transformed to polymeric theaflavin and thearubigin by oxidation occurring during tea fermentation. The distinctive colour, decreased bitterness and astringency, and characteristic flavour are derived from the fermentation process giving fermented teas a marked distinction from non-fermented green tea… The changes in the volatile profile at various fermentation levels results in some compounds increasing in concentration while others decreased. Of the 24 compounds analysed, only four were most abundant in the 0% fermented tea which decreased with increasing fermentation level. These four compounds were dimethyl sulphide, 1-penten-3-ol, toluene and ethylbenzene. Conversely, twelve compounds [2-methyl propanal, 2-butanone, 2-methyl butanal, 3-methyl butanal, pentanol, 2-ethyl furan, heptanal, 6-methyl 5-hepten-2-one, 2-pentyl furan, 2,2,6-trimethyl cyclohexanone, linalool, one unknown] increased in amount as the fermentation level increased.“
[Changes in antioxidant phytochemicals and volatile composition of Camellia sinensis by oxidation during tea fermentation., Kim, Y., Goodner, K.L., Park, J.D., Choi, J., Talcott, S.T., Food Chemistry, Vol.129(4), 2011, 1331-1342]
„The sensory quality ranking of Japanese green tea (Sen-cha) was evaluated and predicted using volatile profiling and multivariate data analyses… The major volatile compounds identified from chromatographic profiles obtained both non-polar and polar columns were coumarin, dihydroactinidiolide, linalool oxides, geraniol, trans-geranylacetone, indole, 6-chloroindole, β-ionone, 5,6-epoxy-β-ionone, cis-jasmone, linalool, methyl jasmonate, trans-nerolidol, 1-octanol, 2-pentanol, phenylethyl alcohol, and phytol… By examining the loadings of PLS–DA, the significant variables contributing to the classification of the high and low quality green tea sample were revealed. They implied that the higher quality green tea samples contained a relatively higher concentration of phytol, caffeine, cis-jasmone, linalool oxide (trans-pyranoid), 6-chloroindole, trans-geranylacetone, methyl jasmonate, and some unknown compounds, compared to the lower quality ones. Whereas, geraniol, linalool, dihydroactinidiolide, linalool oxides (cis- and trans-furanoid), and coumarin were found in the lower concentration in the higher grade green tea samples.“
[Predication of Japanese green tea (Sen-cha) ranking by volatile profiling using gas chromatography mass spectrometry and multivariate analysis., Jumtee, K., Komura, H., Bamba, T., Fukusaki, E., Journal of bioscience and bioengineering, 112(3), 2011, 252-255]
Concentrations and odor activity values of the 16 most potent odorants in black tea infusion were: linalool (142µg/l, OAV 237), geraniol (142µg/l, OAV 45), (E,E,Z)-2,4,6-nonatrienal (1.1µg/l, OAV 41), β-damascenone (0.15µg/l, OAV 38), methylpropanal (69µg/l, OAV 37), 3-methylbutanal (42µg/l, OAV 37), 2-methylbutanal (82µg/l, OAV 37), 3-methyl-2,4-nonandione (0.48µg/l, OAV 37), (E,Z)-2,6-nonadienal (0.56µg/l, OAV 22), (E,E)-2,4-decadienal (2.9µg/l, OAV 18), (Z)-3-hexenol (95µg/l, OAV 7), (Z)-4-heptenal (0.66µg/l, OAV 11), phenylacetaldehyde (57µg/l, OAV 9), β-ionone (1.5µg/l, OAV 7), hexanal (55µg/l, OAV 5), and (E,Z)-2,4-nonadienal (0.45µg/l, OAV 3).
[Schieberle, Peter, and Thomas Hofmann. „Mapping the combinatorial code of food flavors by means of molecular sensory science approach.“ Food Flavors: Chemical, Sensory and Technological Properties. CRC Press, 2011, 413-438]
„Volatile compounds from Pu-erh tea were extracted using a headspace-solid phase microextraction (HS-SPME), and analysed with a gas chromatography-mass spectrometry (GC-MS) and a gas chromatography olfactometry (GC-O). Results showed that a total of 66 major volatile compounds were identified by GC-MS analysis; among them, methoxy-phenolic compounds (33.58%), alcohols (23.01%) and hydrocarbons (11.62%) were the major chemical classes. It was found that 1,2,3-trimethoxybenzene (17.16%) was the most abundant aroma component, followed by α-terpineol (5.68%), 1,2-dimethoxybenzene (4.64%) and linalool oxide II (4.29%) in order. Twenty-nine odour active compounds were perceived by GC-O analysis. Further investigation showed that 1,2-dimethoxybenzene, 1,2,3-trimethoxybenzene, 1,2,3-trimethoxy-5-methylbenzene, 4-ethyl-1,2-dimethoxy-benzene, β-ionone, β-linalool, linalool oxides, decanal, etc. were responsible for the special flavour in Pu-erh tea. It seems that the methoxy-phenolic compounds and alcohols play a vital role in the special flavour of Pu-erh tea.“
[Aroma characterisation of Pu-erh tea using headspace-solid phase microextraction combined with GC/MS and GC–olfactometry., Lv, H.P., Zhong, Q.S., Lin, Z., Wang, L., Tan, J.F., Guo, L., Food Chemistry, Vol.130(4), 2012, 1074-1081]
„The polyphenols, a large group of plant chemicals that includes the catechins, are thought to be responsible for the health benefits that have traditionally been attributed to tea, especially green tea. Major catechins are (-)-epicatechin gallate (ECG), (-)-epicatechin (EC), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG). The most active and abundant catechin in green tea is epigallocatechin-3-gallate (EGCG). Black tea contains much lower concentrations of these catechins than green tea. Oolong tea contains a mixture of simple polyphenols, such as catechins and complex polyphenols.“
[Camellia Sinensis (green tea): a review., Namita, P., Mukesh, R., Vijay, K.J., Global J Pharmacology, Vol.6, 2012, 52-59]
In a sensory analysis of four black tea grades, α-ionone, ethyl caprylate, 3-hydroxy-β-damascone, β-ionone, 2(4H)-benzofuranone (dihydroactinidiolide), nonanal, and β-farnesene were positively correlated with sensory attributes (aroma quality) of black tea.
[Hoang, Q.T., et al. „Sensory aroma and related volatile flavor compound profiles of different black tea grades (camellia sinensis) produced in northern Vietnam.“ in: Fom senses to quality: What can sensory evaluation bring to quality control (2014): 113-119]
„Black tea volatiles are mainly dependent on the oxidation of tea flavonols during fermentation. Virtually, most alcohols, aliphatic acids, phenols, and carbonyls occur in this stage. The degree of partial fermentation determines the constitution and concentration of major aromas in oolong tea, such as jasmine lactones, nerolidol, and methyl jasmonate. Non-fermented green tea contains abundant tea catechins that give it its unique greenish aroma.“
[Tea aroma formation., Ho, C.T., Zheng, X., Li, S., Food Science and Human Wellness, 4(1), 2015, 9-27] http://www.sciencedirect.com/science/article/pii/S221345301500018X
„3-Methyl-2,4-nonanedione has been associated with a prune note in oxidized wine and is an aroma determinant in tea and apricots. Further screening against the entire set of 391 human odorant receptors revealed that 30 or 300 μmol/L 3-methyl-2,4-nonanedione activated only 1 receptor, OR1A1, suggesting a unique role of OR1A1 for the most sensitive detection of this key food odorant in wine, tea, and other food matrices.“
[Geithe, C., Noe, F., Kreissl, J., & Krautwurst, D. (2016). The broadly tuned odorant receptor OR1A1 is highly selective for 3-methyl-2, 4-nonanedione, a key food odorant in aged wines, tea, and other foods. Chemical Senses, bjw117.]
„Volatile flavour components of tea flowers (Camellia sinensis) were isolated by two methods viz. simultaneous distillation extraction (SDE), supercritical fluid extraction (SFE), analyzed by GC and GC/MS and compared with headspace analysis (HS). The composition of the volatile components extracted by the three methods differed considerably. In SFE, phenylethanol (14.7%), linalool (7.9%), (E)-linalool oxide furanoid (3.5%), epoxy linalool (1.6%), geraniol (2.3%) and hotrienol (1.5%) were major components. m-Xylene (2.6%), (E)-linalool oxide pyranoid (5.4%), p-myrcene (5.2%), alpha-cadinol (4.3%) and methyl palmitate (2.9%) were major compounds isolated by SDE. 3-hexenol (2.1%) (E)-4,8-dimethyl-1,3,7-nonatriene (20.9%) and linalool (35.1%) are major components in headspace analysis. Acetophenone and pheromone germacrene D is detected in tea flowers by all the methods studied. Floral, fresh and fruity odour of tea flowers is retained by SFE as there is very little loss of heat sensitive volatiles in SFE. The flavour isolated from SFE has superior quality compared to SDE.“
[Characterization of volatile components of tea flowers (Camellia sinensis) growing in Kangra by GC/MS., Joshi, R., Saini, R., Guleria, S., Babu, G. D., Kumari, M., Gulati, A., Natural product communications, Vol.6(8), 2011, 1155-1158]
Kohl,F.G., Die officinellen Pflanzen der Pharmacopoea Germanica, t.50 (1891-1895)