| Beide Seiten der vorigen Revision
Vorhergehende Überarbeitung
Nächste Überarbeitung
|
Vorhergehende Überarbeitung
|
coffea_arabica_l [2021/06/29 14:21]
andreas |
coffea_arabica_l [2022/02/06 15:03]
andreas |
| "Coffea arabica is believed to be the first species of coffee to be cultivated, being grown in southwest Ethiopia for well over 1,000 years." [[http://en.wikipedia.org/wiki/Coffea_arabica]] | "Coffea arabica is believed to be the first species of coffee to be cultivated, being grown in southwest Ethiopia for well over 1,000 years." [[http://en.wikipedia.org/wiki/Coffea_arabica]] |
| |
| "The volatile components of roasted Arabica and Robusta coffees (powder and brew) were analysed by gas chromatography-olfactometry (GC/O) which revealed the odorants having the highest odor-activity values (ratio of concentration to odor threshold). This procedure resulted in 38 odorants of which 32 were identified. The powders of the two coffee varieties differed in the concentration levels of these compounds. The results indicate that the flavor difference between Arabica and Robusta coffee (powder and brew) are mainly due to the predominance of enoloxo compounds (sotolon, abhexon, furaneol, 3,4-dimethyl-2-hydroxy-2-cyclopentenone) in the former and of 3,5-dimethyl-2-ethylpyrazine, 2,3-diethyl-5-methylpyrazine, 4-ethylguaiacol and 4-vinylguaiacol in the latter. Preparation of brews enhanced the flavor difference, as the concentration levels of water-soluble odorants (furaneol, sotolon, abhexon) responsible for the “sweet-caramel” flavour note increased more in the Arabica than in the Robusta coffee. On the other hand, the alkylpyrazines and guaiacols were responsible for the “spicy, harsh-earthy” aroma of the Robusta coffee. Quantification of selected odorants using a stable isotope dilution assay confirmed the differences between the Arabica and Robusta coffees (brew) found by GC/O." \\ | Most potant odorants (highest FD-factor) of roasted Colombian coffee powder were: 2-methyl-3-furan-thiol (meaty), 2-furanmethanthiol (rosty, coffee-like), methional (cooked potatoes), 3-mercapto-3-methylbutylformate (catty, sweaty), 2-isobutyl-3-methoxypyrazine (paprika-like), 2/3-methylbutyric acid, (E)-ß-damascenone, and furaneol. In coffee beverages the "peasy" off-note is perceivable beginning at 300µg/l and higher. Non-peasy coffees contain this alkoxy pyrazine only in ranges less than 100µg/kg. Some typical mouldy tasting coffees contained about 1µg/kg of 2,4,6-trichloranisole (odor threshold about 0.05ng/l). The earthy note of Robusta coffee corresponds to a great extent to 2-methylisoborneol (2-MIB). This musty, earthy smelling compound with a very low odour threshold of 2.5ng/l in water (2.5ppt) is found in Robusta coffees in amounts to about 200ng/kg, whereas in Arabica coffees it was found at max. 50ng/kg, which is too low for recognition in coffee beverages. \\ |
| | [Vitzthum, O. G., Becker, R., Hölscher, W., and Weisemann, C. "Aroma impact compounds in coffee." in: Aroma production and application. Proceedings of the 3rd Wartburg Aroma Symposium 1991. Editors M. Rothe, H.-P. Kruse, Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke (1992), 211-223] |
| | |
| | Most important odorants of roasted Arabica coffee powder were (highest FD-factor 2048) identified as 3-mercapto-3-methylbutylformate (catty), 3,5-dimethyl-2-ethylpyrazine (earthy-roasty) and (E)-ß-damascenone (honey-like). 2-methyl-3-furan-thiol (meaty), 2,3-diethyl-5-methylpyrazine (earthy-roasty) and bis(2-methyl-3-furyl)disulphide (meaty, sweet) showed very low threshold values (0.001-0.01 ng/1 air). 3,5-Dimethyl-2-ethylpyrazine appeared with the highest FD-factor in Arabica and Robusta coffee powders. \\ |
| | "2,3-Diethyl-5-methylpyrazine and 4-ethylguaiacol were predominant in the Robusta coffee and 3-mercapto-3-methylbutylformate, sotolon and abhexon in the Arabica coffee. Further significant differences were found for 2-methyl-3-furanthiol, phenylacetaldehyde, 3,4-dimethyl-2-cyclopentenol-1-one, 2-/3-methylbutanoic acid and linalool, all predominating in the Arabica coffee, and for 3-methyl-2-buten-1-thiol, which prevailed in the Robusta coffee." \\ |
| [Aroma impact compounds of arabica and robusta coffee. Qualitative and quantitative investigations. Blank, I., Sen, A.,Grosch, W., In Quatorzieme colloque scientifique international sur le cafe, San Francisco, 14-19 juillet 1991, 117-129)] | [Aroma impact compounds of arabica and robusta coffee. Qualitative and quantitative investigations. Blank, I., Sen, A.,Grosch, W., In Quatorzieme colloque scientifique international sur le cafe, San Francisco, 14-19 juillet 1991, 117-129)] |
| |
| [Chlorogenic acid reduces the plasma glucose peak in the oral glucose tolerance test: effects on hepatic glucose release and glycaemia., Bassoli, B.K., Cassolla, P., Borba‐Murad, G.R., Constantin, J., Salgueiro‐Pagadigorria, C.L., Bazotte, R.B., de Souza, H.M., Cell biochemistry and function, 26(3), 2008, 320-328] | [Chlorogenic acid reduces the plasma glucose peak in the oral glucose tolerance test: effects on hepatic glucose release and glycaemia., Bassoli, B.K., Cassolla, P., Borba‐Murad, G.R., Constantin, J., Salgueiro‐Pagadigorria, C.L., Bazotte, R.B., de Souza, H.M., Cell biochemistry and function, 26(3), 2008, 320-328] |
| |
| {{:coffea_arabica.jpg?600}} \\ | {{:coffea_arabica.jpg}} \\ |
| Köhler,F.E., Medizinal Pflanzen, vol.2 t.106 (1890) \\ | Köhler,F.E., Medizinal Pflanzen, vol.2 t.106 (1890) \\ |
| [[http://plantgenera.org/species.php?id_species=262279]] | [[http://plantgenera.org/species.php?id_species=262279]] |
