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Vorhergehende Überarbeitung
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Beide Seiten der Revision
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citrus_paradisi [2017/02/16 11:04]
andreas |
citrus_paradisi [2018/04/22 14:25]
andreas |
| Naringin is the major flavonoid in grapefruit and gives the grapefruit juice its bitter taste. It is metabolized to the cytochrome P450 inhibiting flavanone naringenin in the human body. [[https://en.wikipedia.org/wiki/Naringin]] | Naringin is the major flavonoid in grapefruit and gives the grapefruit juice its bitter taste. It is metabolized to the cytochrome P450 inhibiting flavanone naringenin in the human body. [[https://en.wikipedia.org/wiki/Naringin]] |
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| "By application of the aroma extract dilution analysis on an extract prepared from fresh grapefruit juice, 37 odor-active compounds were detected in the flavor dilution (FD) factor range of 4−256 and subsequently identified. Among them the highest odor activities (FD factors) were determined for ethyl butanoate, [[https://en.wikipedia.org/wiki/Grapefruit_mercaptan|1-p-menthene-8-thiol]], (Z)-3-hexenal, 4,5-epoxy-(E)-2-decenal, [[http://www.thegoodscentscompany.com/data/rw1036031.html|4-mercapto-4-methylpentane-2-one]], 1-heptene-3-one, and wine lactone. Besides the 5 last mentioned compounds, a total of 13 further odorants were identified for the first time as flavor constituents of grapefruit. The data confirmed results of the literature on the significant contribution of 1-p-menthene-8-thiol in grapefruit aroma but clearly showed that a certain number of further odorants are necessary to elicit the typical grapefruit flavor." \\ [Characterization of the Most Odor-Active Volatiles in Fresh, Hand-Squeezed Juice of Grapefruit (Citrus paradisi Macfayden), Andrea Buettner and Peter Schieberle, J. Agric. Food Chem., 47 (12), 1999, 5189-5193] | "By application of the aroma extract dilution analysis on an extract prepared from fresh grapefruit juice, 37 odor-active compounds were detected in the flavor dilution (FD) factor range of 4-256 and subsequently identified. Among them the highest odor activities (FD factors) were determined for ethyl butanoate, [[https://en.wikipedia.org/wiki/Grapefruit_mercaptan|1-p-menthene-8-thiol]], (Z)-3-hexenal, 4,5-epoxy-(E)-2-decenal, [[http://www.thegoodscentscompany.com/data/rw1036031.html|4-mercapto-4-methylpentane-2-one]], 1-heptene-3-one, and wine lactone. Besides the 5 last mentioned compounds, a total of 13 further odorants were identified for the first time as flavor constituents of grapefruit. The data confirmed results of the literature on the significant contribution of 1-p-menthene-8-thiol in grapefruit aroma but clearly showed that a certain number of further odorants are necessary to elicit the typical grapefruit flavor." \\ [Characterization of the Most Odor-Active Volatiles in Fresh, Hand-Squeezed Juice of Grapefruit (Citrus paradisi Macfayden), Andrea Buettner and Peter Schieberle, J. Agric. Food Chem., 47 (12), 1999, 5189-5193] |
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| | {{:grapefruit_mercaptan.jpg| (R)-1-p-menthene-8-thiol }} \\ (R)-1-p-menthene-8-thiol | {{:nootkatone.jpg| (+)-nootkatone }} \\ (+)-nootkatone | | |{{:grapefruit_mercaptan.jpg| (R)-1-p-menthene-8-thiol }} \\ (R)-1-p-menthene-8-thiol |{{:cassis_pentanone.jpg| 4-mercapto-4-methylpentane-2-one}} \\ 4-mercapto-4-methylpentane-2-one |{{:nootkatone.jpg| (+)-nootkatone }} \\ (+)-nootkatone | |
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| Of thirty-eight aroma-active compounds detected in commercial cold-pressed grapefruit oil using GC-O and GC-MS (DB-Wax, DB-1), compounds with the greatest aroma intensities included 1,8-cineole, octanal, dodecanal, trans-4,5-epoxy-(E)-2-decenal, β-sinensal and nootkatone. "The aroma activities of sulphur compounds such as 4-mercapto-4-methyl-2-pentanol and methional were surprisingly low and neither of the two putative grapefruit aroma impact compounds, 4-mercapto-4-methyl-2-pentanone and 1-p-menthene-8-thiol, was detected." \\ | Of thirty-eight aroma-active compounds detected in commercial cold-pressed grapefruit oil using GC-O and GC-MS (DB-Wax, DB-1), compounds with the greatest aroma intensities included 1,8-cineole, octanal, dodecanal, trans-4,5-epoxy-(E)-2-decenal, β-sinensal and nootkatone. "The aroma activities of sulphur compounds such as 4-mercapto-4-methyl-2-pentanol and methional were surprisingly low and neither of the two putative grapefruit aroma impact compounds, 4-mercapto-4-methyl-2-pentanone and 1-p-menthene-8-thiol, was detected." \\ |
| [Evaluation of key aroma compounds in hand-squeezed grapefruit juice (Citrus paradisi Macfayden) by quantitation and flavor reconstitution experiments., Buettner, A., Schieberle, P., Journal of Agricultural and Food Chemistry, 49(3), 2001, 1358-1363] | [Evaluation of key aroma compounds in hand-squeezed grapefruit juice (Citrus paradisi Macfayden) by quantitation and flavor reconstitution experiments., Buettner, A., Schieberle, P., Journal of Agricultural and Food Chemistry, 49(3), 2001, 1358-1363] |
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| "The sesquiterpene ketone [[http://en.wikipedia.org/wiki/Nootkatone|(+)-nootkatone]], which possesses a citrus-like character and a bitter taste, also occurs as a typical constituent in almost all peel oils. [grapefruit 0.5-1.8%, grapefruit juice 3.3%] Due to its low odor treshold of 800μg/l water, this bicyclic sesquiterpene contributes much to the overall character of an essential oil even at concentrations below 0.001% (10.000ppb). Its enantiomer (-)-nootkatone lacks both the citrus character and the low treshold... The characteristic fresh fruity top-note of grapefruit juice is mainly due to p-menth-1-ene-8-thiol, which is present only in concentrations below 1ppb. [This] Compound has an odor treshold of 0.1ng/l water, ... one of the lowest odor tresholds of all naturall aroma chemicals." \\ | "The sesquiterpene ketone [[http://en.wikipedia.org/wiki/Nootkatone|(+)-nootkatone]], which possesses a citrus-like character and a bitter taste, also occurs as a typical constituent in almost all peel oils [of citrus fruits, like lemon peel 0.06%, grapefruit peel 0.5-1.8%, but grapefruit juice oil 3.3% (!)]. Due to its low odor treshold of 800μg/l water, this bicyclic sesquiterpene contributes much to the overall character of an essential oil even at concentrations below 0.001% (10.000ppb). Its enantiomer (-)-nootkatone lacks both the citrus character and the low treshold... The characteristic fresh fruity top-note of grapefruit juice is mainly due to p-menth-1-ene-8-thiol, which is present only in concentrations below 1ppb. [This] Compound has an odor treshold of 0.1ng/l water, ... one of the lowest odor tresholds of all naturall aroma chemicals." \\ |
| [Scent and Chemistry, Günther Ohloff, Wilhelm Pickenhagen, Philip Kraft, Wiley-VCH, 2012, 222ff] | [Scent and Chemistry, Günther Ohloff, Wilhelm Pickenhagen, Philip Kraft, Wiley-VCH, 2012, 222ff] |
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