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 Small trees or large shrubs, 5-8m tall, native to Etiopia, cultivated in moist, usually cool tropical regions. "This species is tetraploid and is the source of "Arabica Coffee." It has been widely hybridized with several other Coffea species to produce commercial coffee plants; flower size varies markedly among many of these." [[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200022076]] Small trees or large shrubs, 5-8m tall, native to Etiopia, cultivated in moist, usually cool tropical regions. "This species is tetraploid and is the source of "Arabica Coffee." It has been widely hybridized with several other Coffea species to produce commercial coffee plants; flower size varies markedly among many of these." [[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200022076]]
  
-"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|wikipedia]]
  
-"The volatile components of roasted Arabica and Robusta coffees (powder and brew) were analysed by gas chromatography-olfactometry (GC/Owhich 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 compoundsThe results indicate that the flavor difference between Arabica and Robusta coffee (powder and brew) are mainly due to the predominance of enoloxo compounds (sotolonabhexonfuraneol3,4-dimethyl-2-hydroxy-2-cyclopentenonein 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 (furaneolsotolon, abhexonresponsible for the “sweet-caramel” flavour note increased more in the Arabica than in the Robusta coffee. On the other handthe 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. RotheH.-P. KruseDeutsches 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 (meatysweetshowed 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)] 
  
-|{{:sotolon.jpg|sotolon}} \\ sotolon \\ (3-hydroxy-4,5-dimethyl-2(5H)-furanone, caramel furanone) |{{:hdmf.jpg|furaneol}} \\ furaneol \\ (4-hydroxy-2,5-dimethyl-3(2H)-furanone) |{{:2-ethyl-3_5-dimethylpyrazine.jpg|2-ethyl-3,5-dimethylpyrazine}} \\ 2-ethyl-3,5-dimethylpyrazine |{{4-vinylguaiacol.jpg|4-vinylguaiacol}} \\ 4-vinylguaiacol |{{:furfurylmercaptan.jpg| 2-furfurylthiol }} \\ furfuryl mercaptan \\ (2-furfurylthiol) |+|{{:sotolon.jpg|sotolon}} \\ sotolon \\ (3-hydroxy-4,5-dimethyl-2(5H)-furanone) |{{:hdmf.jpg|furaneol}} \\ furaneol \\ (4-hydroxy-2,5-dimethyl-3(2H)-furanone) |{{:2-ethyl-3_5-dimethylpyrazine.jpg|2-ethyl-3,5-dimethylpyrazine}} \\ 2-ethyl-3,5-dimethylpyrazine |{{4-vinylguaiacol.jpg|4-vinylguaiacol}} \\ 4-vinylguaiacol |{{:furfurylmercaptan.jpg| 2-furfurylthiol }} \\ furfuryl mercaptan \\ (2-furfurylthiol) |
  
 "The potent odorants were quantified in a sample of roasted Arabica coffee. On the basis of the results, 27 odorants were dissolved in an oil/water mixture. The flavor profile of the model obtained was very close to that of the real sample. In duo and triangle tests, the model was compared with models missing one or more odorants. These experiments indicated that 2-furfurylthiol, 4-vinylguaiacol, several alkyl pyrazines, furanones, acetaldehyde, propanal, methylpropanal, and 2- and 3-methylbutanal had the greatest impact on the coffee flavor." The omission experiments for [[http://www.thegoodscentscompany.com/data/rw1008451.html|2-furfurylthiol]] confirmed that it is a key component of coffee "The potent odorants were quantified in a sample of roasted Arabica coffee. On the basis of the results, 27 odorants were dissolved in an oil/water mixture. The flavor profile of the model obtained was very close to that of the real sample. In duo and triangle tests, the model was compared with models missing one or more odorants. These experiments indicated that 2-furfurylthiol, 4-vinylguaiacol, several alkyl pyrazines, furanones, acetaldehyde, propanal, methylpropanal, and 2- and 3-methylbutanal had the greatest impact on the coffee flavor." The omission experiments for [[http://www.thegoodscentscompany.com/data/rw1008451.html|2-furfurylthiol]] confirmed that it is a key component of coffee
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 "...  aroma freshness of whole roasted coffee is mainly determined by certain low-boiling components, namely low-molecular weight sulphur compounds, Strecker aldehydes and α-dicarbonyls. The loss of aroma freshness was due to the loss of certain aroma impact volatiles, mainly methanethiol, which then could be used as an indicator of freshness. The heavier components, such as furfurylmercaptan, will remain in the coffee and will cause an ‘ageing’ note. In addition, an increase of dimethylsulphide, the oxidation product of methanethiol, was observed, although no ‘true’ staling compound was found." \\ "...  aroma freshness of whole roasted coffee is mainly determined by certain low-boiling components, namely low-molecular weight sulphur compounds, Strecker aldehydes and α-dicarbonyls. The loss of aroma freshness was due to the loss of certain aroma impact volatiles, mainly methanethiol, which then could be used as an indicator of freshness. The heavier components, such as furfurylmercaptan, will remain in the coffee and will cause an ‘ageing’ note. In addition, an increase of dimethylsulphide, the oxidation product of methanethiol, was observed, although no ‘true’ staling compound was found." \\
 [Steinhart H, Holscher W. In Proceedings of the 14th ASIC Meeting, San Francisco, 1991, 156-164] \\ [Steinhart H, Holscher W. In Proceedings of the 14th ASIC Meeting, San Francisco, 1991, 156-164] \\
-[Coffee flavour: an overview., Buffo, R.A., Cardelli-Freire, C., Flavour and fragrance journal, 19(2), 2004, 99-104] [[http://www2.hcmuaf.edu.vn/data/lhquang/file/Coffee/coffee%20flavour.pdf]]+[Coffee flavour: an overview., Buffo, R.A., Cardelli-Freire, C., Flavour and fragrance journal, 19(2), 2004, 99-104] [[http://www2.hcmuaf.edu.vn/data/lhquang/file/Coffee/coffee%20flavour.pdf|PDF]] 
 + 
 +| {{:methional.jpg|methional}} \\ methional \\ //(potato-like)// | {{3mercapto3methylbutylformate.png| 3-mercapto-3-methylbutyl formate }} \\ 3-mercapto-3-methylbutyl formate \\ //(catty roasty)// |
  
 "The more potent odorants in a sample of medium-roasted Arabica coffee and in the corresponding brew were quantified. Large amounts ( >75%) of acetaldehyde, 2,3-butanedione, 2,3-pentanedione, vanillin and some furanones were extracted from the coffee brew, whereas the yields of the more unpolar compounds, such as 3-isobutyl-2-methoxypyrazine, (E)-β-damascenone and the unstable 2-furfurylthiol were low (<25%). On the basis of quantitative data an aroma model was prepared for the brew. In triangle tests, models containing the complete set of 24 odorants were compared with a model missing one or more odorants. These experiments indicated that the aroma of the brew was mainly caused by some alkylpyrazines, furanones and phenols, and by 2-furfurylthiol, methional and 3-mercapto-3-methylbutyl formate. The higher impact of both methional and the formate on the aroma of the brew and the lower aroma activity of 4-vinylguaiacol were in contrast to results obtained in a previous study for ground coffee of the same provenance and roast degree." \\ "The more potent odorants in a sample of medium-roasted Arabica coffee and in the corresponding brew were quantified. Large amounts ( >75%) of acetaldehyde, 2,3-butanedione, 2,3-pentanedione, vanillin and some furanones were extracted from the coffee brew, whereas the yields of the more unpolar compounds, such as 3-isobutyl-2-methoxypyrazine, (E)-β-damascenone and the unstable 2-furfurylthiol were low (<25%). On the basis of quantitative data an aroma model was prepared for the brew. In triangle tests, models containing the complete set of 24 odorants were compared with a model missing one or more odorants. These experiments indicated that the aroma of the brew was mainly caused by some alkylpyrazines, furanones and phenols, and by 2-furfurylthiol, methional and 3-mercapto-3-methylbutyl formate. The higher impact of both methional and the formate on the aroma of the brew and the lower aroma activity of 4-vinylguaiacol were in contrast to results obtained in a previous study for ground coffee of the same provenance and roast degree." \\
Zeile 25: Zeile 31:
  
 [[http://www.thegoodscentscompany.com/data/rw1013601.html|2-isobutyl-3-methoxypyrazine]] "... is the most aroma-active constituent of raw coffee and is stable during roasting,... so roasting of the raw material not only produces the pleasant aroma which is characteristic for coffee but, in addition, generates odorants which suppress the peasy odour note [of 2-isobutyl-3-methoxypyrazine]." \\ [[http://www.thegoodscentscompany.com/data/rw1013601.html|2-isobutyl-3-methoxypyrazine]] "... is the most aroma-active constituent of raw coffee and is stable during roasting,... so roasting of the raw material not only produces the pleasant aroma which is characteristic for coffee but, in addition, generates odorants which suppress the peasy odour note [of 2-isobutyl-3-methoxypyrazine]." \\
-[Evaluation of the key odorants of foods by dilution experiments, aroma models and omission., Grosch, W., Chemical senses, 26(5), 2001, 533-545] [[http://chemse.oxfordjournals.org/content/26/5/533.full]]+[Evaluation of the key odorants of foods by dilution experiments, aroma models and omission., Grosch, W., Chemical senses, 26(5), 2001, 533-545] [[http://chemse.oxfordjournals.org/content/26/5/533.full|PDF]]
  
 {{:2-isobutyl-3-methoxypyrazine.jpg|}} 2-isobutyl-3-methoxypyrazine \\ {{:2-isobutyl-3-methoxypyrazine.jpg|}} 2-isobutyl-3-methoxypyrazine \\
Zeile 34: Zeile 40:
 " ...as concerns the Arabica class, the El Salvador sample was characterized by higher amounts of ketones (2,3-butanedione, 2,3-pentanedione, 1-hydroxy-2-butanone), especially diketones and aldehydes (2-methylbutanal, 3-methylbutanal, furfural), in particular butanal derivatives. Costa Rica coffee presented the most abundant substituted pyrazine fraction (2,5-dimethylpyrazine, 2,6-dimethylpyrazine, ethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, 2-ethyl-3-methylpyrazine). Furthermore, it was characterized by the highest amount of guaiacol (0.526%) and the lowest amount of pyridine (5.181%). Santos coffee followed more or less the same behaviour with the exception of some of the furfuryl compounds (furfuryl alcohol, furfuryl ether) which were more concentrated in this matrix." \\ " ...as concerns the Arabica class, the El Salvador sample was characterized by higher amounts of ketones (2,3-butanedione, 2,3-pentanedione, 1-hydroxy-2-butanone), especially diketones and aldehydes (2-methylbutanal, 3-methylbutanal, furfural), in particular butanal derivatives. Costa Rica coffee presented the most abundant substituted pyrazine fraction (2,5-dimethylpyrazine, 2,6-dimethylpyrazine, ethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, 2-ethyl-3-methylpyrazine). Furthermore, it was characterized by the highest amount of guaiacol (0.526%) and the lowest amount of pyridine (5.181%). Santos coffee followed more or less the same behaviour with the exception of some of the furfuryl compounds (furfuryl alcohol, furfuryl ether) which were more concentrated in this matrix." \\
 [Reliable characterization of coffee bean aroma profiles by automated headspace solid phase microextraction‐gas chromatography‐mass spectrometry with the support of a dual‐filter mass spectra library., Mondello, L., Costa, R., Tranchida, P.Q., Dugo, P., Lo Presti, M., Festa, S., Dugo, G., Journal of separation science, 28(9‐10), 2005, 1101-1109] [Reliable characterization of coffee bean aroma profiles by automated headspace solid phase microextraction‐gas chromatography‐mass spectrometry with the support of a dual‐filter mass spectra library., Mondello, L., Costa, R., Tranchida, P.Q., Dugo, P., Lo Presti, M., Festa, S., Dugo, G., Journal of separation science, 28(9‐10), 2005, 1101-1109]
 +
 +The most abundant alkylpyrazine in coffee powder was 2-methylpyrazine, followed by 2,6-dimethylpyrazine, 2,5-dimethylpyrazine, 2-ethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, and 2,3,5-trimethylpyrazine. The total concentrations of alkylpyrazines in commercially available ground coffee ranged between 82.1 and 211.6 mg/kg, respectively. \\
 +Alkylpyrazine profiles of coffee beverages are similar to those of the coffee used. In total, 70-82% of the alkylpyrazines (113-132mg/kg), depending on the brewing method, passed into beverages during the brewing process. \\
 +[Pickard, Stephanie, et al. "Determination of the alkylpyrazine composition of coffee using stable isotope dilution-gas chromatography-mass spectrometry (SIDA-GC-MS)." Journal of agricultural and food chemistry 61.26 (2013): 6274-6281] and \\
 +[Pickard, Stephanie, Helene Wilms, and Elke Richling. "Alkylpyrazine contents of coffee beverages using stable isotope dilution gas chromatography-mass spectrometry." LWT-Food Science and Technology 58.1 (2014): 188-193]
  
 ---- ----
 +
 Chlorogenic acid-rich green coffee extract is used to induce weight loss. Giving 200mg extract or placebo twice a day with the main meal for 60 days, changes in weight were -4.9kg in verum and -2.4kg in placebo group; body mass index (BMI) changes observed were -1.9 (verum) and -0.9 (placebo). It was suggested that chlorogenic acid is able to lowering blood sugar by inhibition of hepatic glucose-6-phosphatase. \\ Chlorogenic acid-rich green coffee extract is used to induce weight loss. Giving 200mg extract or placebo twice a day with the main meal for 60 days, changes in weight were -4.9kg in verum and -2.4kg in placebo group; body mass index (BMI) changes observed were -1.9 (verum) and -0.9 (placebo). It was suggested that chlorogenic acid is able to lowering blood sugar by inhibition of hepatic glucose-6-phosphatase. \\
-[Svetol, green coffee extract, induces weight loss and increases the lean to fat mass ratio in volunteers with overweight problem., Dellalibera, O., Lemaire, B., Lafay, S., Phytotherapie, 4(4), 2006, 194-197] [[http://www.realdose.com/wp-content/uploads/2012/01/Effect_of_Svetol_on_weight_loss_on_humans.pdf]]+[Svetol, green coffee extract, induces weight loss and increases the lean to fat mass ratio in volunteers with overweight problem., Dellalibera, O., Lemaire, B., Lafay, S., Phytotherapie, 4(4), 2006, 194-197] [[http://www.realdose.com/wp-content/uploads/2012/01/Effect_of_Svetol_on_weight_loss_on_humans.pdf|PDF]]
  
 Though chlorogenic acid (1mM) inhibited about 40% of glucose-6-phosphatase activity in the microsomal fraction of hepatocytes, no effect was observed on production of glucose from gluconeogenesis or on L-alanine catabolism at various concentrations in liver perfusion experiments. It is possible that this compound did not reach sufficiently high intracellular levels to inhibit the target enzyme. Intravenous administration of chlorogenic acid also failed to provoke a reduction in blood glucose levels. Chlorogenic acid promoted a significant reduction in the plasma glucose peak at 10 and 15 min during the oral glucose tolerance test (OGTT), probably by attenuating intestinal glucose absorption. \\ Though chlorogenic acid (1mM) inhibited about 40% of glucose-6-phosphatase activity in the microsomal fraction of hepatocytes, no effect was observed on production of glucose from gluconeogenesis or on L-alanine catabolism at various concentrations in liver perfusion experiments. It is possible that this compound did not reach sufficiently high intracellular levels to inhibit the target enzyme. Intravenous administration of chlorogenic acid also failed to provoke a reduction in blood glucose levels. Chlorogenic acid promoted a significant reduction in the plasma glucose peak at 10 and 15 min during the oral glucose tolerance test (OGTT), probably by attenuating intestinal glucose absorption. \\
 [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?500}} \\ +{{:coffea_arabica.jpg?700}} \\ 
-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|plantgenera.org]] 
-[[http://plantgenera.org/species.php?id_species=262279]]+ 
 +{{:coffea_ara.jpg?700|Coffea arabica}} \\  
 +Coffea arabica, Colombia (2022) © Arm C.S. [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]] [[https://www.inaturalist.org/observations?taxon_id=64342|inaturalist.org]]  
 + 
coffea_arabica_l.1506506311.txt.gz · Zuletzt geändert: 2017/09/27 09:58 von andreas

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