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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.
Instant coffee is a beverage derived from brewed coffee beans that enables people to quickly prepare hot coffee by adding hot water or milk to coffee solids in powdered or crystallized form and stirring. The product was first invented in Invercargill, the largest city in Southland, New Zealand, in 1890. Instant coffee solids refers to the dehydrated and packaged solids available at retail used to make instant coffee. Instant coffee solids are commercially prepared by either freeze-drying or spray drying, after which it can be rehydrated. Instant coffee in a concentrated liquid form, as a beverage, is also manufactured.
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, 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.
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.
In organic chemistry, a carbamate is a category of organic compounds with the general formula R2NC(O)OR and structure >N−C(=O)−O−, which are formally derived from carbamic acid. The term includes organic compounds, formally obtained by replacing one or more of the hydrogen atoms by other organic functional groups; as well as salts with the carbamate anion H2NCOO−.
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.
Trigonelline is an alkaloid with chemical formula C7H7NO2. It is a zwitterion formed by the methylation of the nitrogen atom of niacin (vitamin B3). Trigonelline is a product of niacin metabolism that is excreted in the urine of mammals.
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.
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.
Tomatine is a glycoalkaloid, found in the stems and leaves of tomato plants, and in the fruits at much lower concentrations. Chemically pure tomatine is a white crystalline solid at standard temperature and pressure.
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.
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouthfeel of tea. Polyphenols in tea include catechins, theaflavins, tannins, and flavonoids.
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:
References
- ↑ Clarke, Ronald James; Macrae, Robert, eds. (1985). Coffee Volume 1 Chemistry. Vol. 1 (1 ed.). New York, USA; Barking, Essex, UK: Elsevier Applied Science Publishers Ltd. ISBN 0-85334-368-3. LCCN 85-6976. (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.
