Related Research Articles
Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar structure may also be termed alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen or sulfur. More rarely still, they may contain elements such as phosphorus, chlorine, and bromine.
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used as a eugeroic (wakefulness promoter) or as a mild cognitive enhancer to increase alertness and attentional performance. Caffeine acts by blocking binding of adenosine to the adenosine A1 receptor, which enhances release of the neurotransmitter acetylcholine. Caffeine has a three-dimensional structure similar to that of adenosine, which allows it to bind and block its receptors. Caffeine also increases cyclic AMP levels through nonselective inhibition of phosphodiesterase.
Guaraná is a climbing plant in the family Sapindaceae, native to the Amazon basin and especially common in Brazil. Guaraná has large leaves and clusters of flowers, and is best known for the seeds from its fruits, which are about the size of a coffee bean.
The Maillard reaction is a chemical reaction between amino acids and reducing sugars to create melanoidins, the compounds which give browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, falafel and many other foods undergo this reaction. It is named after French chemist Louis Camille Maillard, who first described it in 1912 while attempting to reproduce biological protein synthesis. The reaction is a form of non-enzymatic browning which typically proceeds rapidly from around 140 to 165 °C. Many recipes call for an oven temperature high enough to ensure that a Maillard reaction occurs. At higher temperatures, caramelization and subsequently pyrolysis become more pronounced.
Gyokuro is a type of shaded green tea from Japan. It differs from the standard sencha in being grown under the shade rather than the full sun. The name "gyokuro" translates as "jewel dew". According to the Japan Tea Central Association, gyokuro is defined as "a tea manufactured in the same manner as sencha from tea leaves picked from covered tea gardens that are almost completely shaded from sunlight for about 20 days using covering materials such as reed screens, straw, or shading nets, from the time when the new shoots of the first flush start to grow."
Diacetyl ( dy-yuh-SEE-tuhl; IUPAC systematic name: butanedione or butane-2,3-dione) is an organic compound with the chemical formula (CH3CO)2. It is a yellow liquid with an intensely buttery flavor. It is a vicinal diketone (two C=O groups, side-by-side). Diacetyl occurs naturally in alcoholic beverages and some cheeses and is added as a flavoring to some foods to impart its buttery flavor.
Decaffeination is the removal ("de-") of caffeine from coffee beans, cocoa, tea leaves, and other caffeine-containing materials. Decaffeinated products are commonly termed by the abbreviation decaf. Decaffeinated drinks contain typically 1–2% of the original caffeine content, but sometimes as much as 20%.
An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently volatile for transmission via the air to the olfactory system in the upper part of the nose. As examples, various fragrant fruits have diverse aroma compounds, particularly strawberries which are commercially cultivated to have appealing aromas, and contain several hundred aroma compounds.
Organochlorine chemistry is concerned with the properties of organochlorine compounds, or organochlorides, organic compounds containing at least one covalently bonded atom of chlorine. The chloroalkane class includes common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with TCDD being one of the most notorious.
A coffee bean is a seed from the Coffea plant and the source for coffee. It is the pit inside the red or purple fruit. This fruit is often referred to as a coffee cherry, and like the cherry, it is a fruit with a pit. Even though the coffee beans are not technically beans, they are referred to as such because of their resemblance to true beans. The fruits most commonly contain two stones with their flat sides together. A small percentage of cherries contain a single seed, called a "peaberry". Peaberries make up only around 10% to 15% of all coffee beans. It is a fairly common belief that they have more flavour than normal coffee beans. Like Brazil nuts and white rice, coffee beans consist mostly of endosperm.
Chlorogenic acid (CGA) is the ester of caffeic acid and (−)-quinic acid, functioning as an intermediate in lignin biosynthesis. The term chlorogenic acids refers to a related polyphenol family of esters, including hydroxycinnamic acids with quinic acid.
Roasting coffee transforms the chemical and physical properties of green coffee beans into roasted coffee products. The roasting process is what produces the characteristic flavor of coffee by causing the green coffee beans to change in taste. Unroasted beans contain similar if not higher levels of acids, protein, sugars, and caffeine as those that have been roasted, but lack the taste of roasted coffee beans due to the Maillard and other chemical reactions that occur during roasting.
Paraxanthine, also known as 1,7-dimethylxanthine, is a metabolite of theophylline and theobromine, two well-known stimulants found in coffee, tea, and chocolate mainly in the form of caffeine. It is a member of the xanthine family of alkaloids, which includes theophylline, theobromine and caffeine.
2-Ethylhexanol is an organic compound with the chemical formula CH3CH2CH2CH2CH(CH2CH3)CH2OH. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in plants, fruits, and wines. The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.
Coffee cupping, or coffee tasting, is the practice of observing the tastes and aromas of brewed coffee. It is a professional practice but can be done informally by anyone or by professionals known as "Q Graders". A standard coffee cupping procedure involves deeply sniffing the coffee, then slurping the coffee from a spoon so it is aerated and spread across the tongue. The coffee taster attempts to measure aspects of the coffee's taste, specifically the body, sweetness, acidity, flavour, and aftertaste. Since coffee beans embody telltale flavours from the region where they were grown, cuppers may attempt to identify the coffee's origin.
Ann C. Noble is a sensory chemist and retired professor from the University of California, Davis. During her time at the UC Davis Department of Viticulture and Enology, Noble invented the "Aroma Wheel" which is credited with enhancing the public understanding of wine tasting and terminology. At the time of her hiring at UC Davis in 1974, Noble was the first woman hired as a faculty member of the Viticulture department. Noble retired from Davis in 2002 and in 2003 was named Emeritus Professor of Enology. Since retirement she has participated as a judge in the San Francisco Chronicle Wine Competition.
Low caffeine coffee is a term that is used by coffee producers to describe coffee that has not been subjected to a process of decaffeination, but is substantially lower in caffeine than average coffee. Samples of coffee vary widely in caffeine levels due to many factors, some well documented and some not fully understood, such as the action of soil, water levels and sunlight. Low caffeine coffees are typically created by assaying caffeine levels of different bean lots and selecting the best flavor profile from the lots that are naturally lowest in caffeine.
In viticulture, ripeness is the completion of the ripening process of wine grapes on the vine which signals the beginning of harvest. What exactly constitutes ripeness will vary depending on what style of wine is being produced and what the winemaker and viticulturist personally believe constitutes ripeness. Once the grapes are harvested, the physical and chemical components of the grape which will influence a wine's quality are essentially set so determining the optimal moment of ripeness for harvest may be considered the most crucial decision in winemaking.
Caffeoylquinic acids (CQA) are compounds composed of a quinic acid core, acylated with one or more caffeoyl groups. There is a positive correlation between the number of caffeoyl groups bound to quinic acid and the rate of ATP production. Compounds of this class include:
Caffeine dehydrogenase, commonly referred to in scientific literature as caffeine oxidase, is an enzyme with the systematic name caffeine:ubiquinone oxidoreductase. The enzyme is most well known for its ability to directly oxidize caffeine, a type of methylxanthine, to trimethyluric acid. Caffeine dehydrogenase can be found in bacterium Pseudomonas sp. CBB1 and in several species within the genera Alcaligenes, Rhodococcus, and Klebsiella.
References
- ↑ Clarke, Ronald James; Macrae, Robert, eds. (1985). Coffee Volume 1 Chemistry. Vol. 1 (1 ed.). New York, USA; London,UL; Barking, Essex, UK: Elsevier Applied Science Publishers Ltd. ISBN 0-85334-368-3. LCCN 85-6976. (xiv+306 pages)
- ↑ Flament, Ivon; Bessière-Thomas, Yvonne (2002) [October 2001]. Written at Geneva, Switzerland. Coffee Flavor Chemistry (1 ed.). Chichester, West Sussex, UK: John Wiley & Sons, Ltd. ISBN 0-471-72038-0. LCCN 2001024880 . Retrieved 2024-07-16. (xiv+410 pages)
- ↑ Capek, Peter; Paulovičová, Ema; Matulová, Mária; Mislovičová, Danica; Navarini, Luciano; Suggi-Liverani, Furio (2014-03-15). "Coffea arabica instant coffee—Chemical view and immunomodulating properties". Carbohydrate Polymers . 103: 418–426. doi:10.1016/j.carbpol.2013.12.068. PMID 24528749.
- ↑ Green, Paul W. C.; Davis, Aaron P.; Cossé, Allard A.; Vega, Fernando E. (2015-11-04). "Can Coffee Chemical Compounds and Insecticidal Plants Be Harnessed for Control of Major Coffee Pests?". Journal of Agricultural and Food Chemistry . 63 (43): 9427–9434. doi:10.1021/acs.jafc.5b03914. PMID 26458882 – via Hunter College Libraries.
- 1 2 Herraiz, Tomas; Chaparro, Carolina (2006-01-18). "Human monoamine oxidase enzyme inhibition by coffee and beta-carbolines norharman and harman isolated from coffee". Life Sciences . 78 (8): 795–802. doi:10.1016/j.lfs.2005.05.074. PMID 16139309.
