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Vorhergehende Überarbeitung
Nächste Überarbeitung
Beide Seiten der Revision
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camellia_sinensis_l._kuntze [2018/05/01 10:52]
andreas |
camellia_sinensis_l._kuntze [2018/08/28 10:36]
andreas |
| "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." \\ | "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] | [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] |
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| | 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] |
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| "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." \\ | "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." \\ |
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| "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." \\ | "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] | [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] |
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| 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. \\ | 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. \\ |
