| Beide Seiten der vorigen RevisionVorhergehende Überarbeitung | |
| coffea_canephora_pierre_ex_froehner [2016/05/12 08:47] – andreas | coffea_canephora_pierre_ex_froehner [2025/12/06 20:02] (aktuell) – andreas |
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| Shrub or small tree, 4-8m tall, native to tropical Africa, naturalized and commonly cultivated win tropics; leaves elliptic, elliptic-oblong, or ovate-oblong, crisped-undulate, apex acuminate; inflorescences with 1-3 cymes in each axil, each cyme 3-6-flowered; corolla white to pink, funnelform, tube 5-16 mm; lobes (5-7, elliptic, 8-19 mm; drupe red, subglobose, 10-12mm in diam. "This species is diploid and is cultivated as //Robusta Coffee//. It has been widely hybridized with several other species to produce commercial coffee plants. [[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200022077]] | Shrub or small tree, 4-8m tall, native to tropical Africa, naturalized and commonly cultivated win tropics; leaves elliptic, elliptic-oblong, or ovate-oblong, crisped-undulate, apex acuminate; inflorescences with 1-3 cymes in each axil, each cyme 3-6-flowered; corolla white to pink, funnelform, tube 5-16 mm; lobes (5-7, elliptic, 8-19 mm; drupe red, subglobose, 10-12mm in diam. "This species is diploid and is cultivated as //Robusta Coffee//. It has been widely hybridized with several other species to produce commercial coffee plants. [[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200022077]] |
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| | "With approximately 40% of the world's coffee harvest, Robusta is the second most important coffee variety after Arabica. This variety is less susceptible to disease, heat, and high humidity. It also produces more fruit that ripens faster... The taste of Robusta is earthy to woody. While Robusta is more bitter and has fewer aromas than Arabica, it has a fuller body, which is why it is particularly valued for espresso. Its caffeine content, at two to four percent, is about twice that of Arabica coffee." [[https://de.wikipedia.org/wiki/Robusta-Kaffee|wikipedia(DE)]] |
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| „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-cyclopentene-1-one) 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.“ \\ | „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-cyclopentene-1-one) 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.“ \\ |
| [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)] |
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| |{{:2-ethyl-3_5-dimethylpyrazine.jpg|2-ethyl-3,5-dimethylpyrazine}} \\ 2-ethyl-3,5-dimethylpyrazine |{{4-vinylguaiacol.jpg|4-vinylguaiacol}} \\ 4-vinylguaiacol |{{:2methylisoborneol.jpg|2-methylisoborneol}} \\ [[http://www.leffingwell.com/chirality/methylisoborneol.htm|2-methylisoborneol]] | | |{{:2-ethyl-3_5-dimethylpyrazine.jpg|2-ethyl-3,5-dimethylpyrazine}} \\ 2-ethyl-3,5-dimethylpyrazine |{{4-vinylguaiacol.jpg|4-vinylguaiacol}} \\ 4-vinylguaiacol |{{:2methylisoborneol.jpg|2-methylisoborneol}} \\ 2-methylisoborneol | |
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| In various roasted Robusta coffee samples, 2-methylisoborneol was found at 120-430 ng/kg (dry matter) and assigned as earthy smelling character impact compound. \\ | In various roasted Robusta coffee samples, [[http://www.leffingwell.com/chirality/methylisoborneol.htm|2-methylisoborneol]] was found at 120-430 ng/kg (dry matter) and assigned as earthy smelling character impact compound. \\ |
| [Flavor chemistry: Thirty Years of Progress., Teranishi, R., Wick, E.L., Hornstein, I. (Eds.), Springer Science & Business Media, 1999, 122-127] | [Flavor chemistry: Thirty Years of Progress., Teranishi, R., Wick, E.L., Hornstein, I. (Eds.), Springer Science & Business Media, 1999, 122-127] |
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| [On the role of (-)-2-methylisoborneol for the aroma of robusta coffee., Blank, I., Grosch, W., Journal of agricultural and food chemistry, 50(16), 2002, 4653-4656] | [On the role of (-)-2-methylisoborneol for the aroma of robusta coffee., Blank, I., Grosch, W., Journal of agricultural and food chemistry, 50(16), 2002, 4653-4656] |
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| {{:coffea_canephora.jpg?800}} \\ | {{:coffea_canephora.jpg|Coffea canephora}} \\ |
| Coffea canephora 2 at Aanakkulam, Author: Jeevan Jose, Kerala, India (2010) \\ [[https://creativecommons.org/licenses/by-sa/4.0/legalcode|Creative Commons Attribution-ShareAlike 4.0 International License]] | Coffea canephora, Kamerun (2018) © meganjoan [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]] [[https://www.inaturalist.org/observations?taxon_id=64345|inaturalist.org]] |
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