what is in a cup of coffee

98.75% is water

Green coffee contained about 6–7% of sucrose as soluble sugars and low amount of glucose. The soluble sugars of roasted coffee were sucrose, fructose, and glucose

The main constituents of coffee are caffeine, tannin, fixed oil, carbohydrates, and proteins. It contains 2–3% caffeine, 3–5% tannins, 13% proteins, and 10–15% fixed oils. In the seeds, caffeine is present as a salt of chlorogenic acid (CGA). Also it contains oil and wax.

Caffeine

2-Ethylphenol
- crema

Quinic acid
- acidic profile

3.5 Dicaffeoylquinic Acid

Sulfur-containing compounds, including 2-furfurylthiol. "roasted coffee" aroma

Dimethyl disulfide
- garlicky profile

Trigonelline
- sweet, earthy flavor

Niacin

Acetylmethylcarbinol
-buttery flavor

Putrescine
- scent of dying amino acids

Theophylline

Cafestol
- oils you see floating on the top of the crema

Kahweol
- a layer of oils along the crema that adds aromatic nuances to a cup of coffee

triglycerides

- flavors, aroma

Guaiacol: burnt wood, smokey aroma, spicy

3-methyl butanal: fruity, green

methyl propanal:floral, spicy

aldehydes, acetaldyhyde: pungent, fruity,

diacetyl: butterscotch (popcorn)

furans, furanone, furaneol: burnt sugar,caramel

pyrazines: earthy

2-isobutyl-3-methoxypyrazine: green pepper aroma

2-ethyl-3,5-dimethylpyrazine: nutty flavour

coffee green bean:

Coffee beans contain carbohydrate (50%), protein (10%), fat (12%), and other chemicals such as acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, phenolics, 4-vinylguaiacol, phenylacetaldehyde, gamma-damascenone, isoeugenol, caffeic acid, ferulic acid, CHAs, terpenoids, 2-methylisoborneol, cafestol, kahweol, phytosterol, sitosterol, caffeine, theobromine, trigonelline, serotonin, norharman, harman, pyrazines, and others.

After roasting, new chemicals also can appear: acetaldehyde, furan, furfuraldehyde, furfuryl alcohol, diacetyl, methyl mercaptan, furfuryl mercaptan, dimethyl sulfide, acetylpropionyl, guaiacol, vinyl guaiacol, pyrazine, n-methylpyrrole, methyl carbinol, caffeoylquinic-lactones, niacin, and melanoidins. Most of niacin is formed from trigonelline, and melanoidins are formed as a result of pyrolysis and the Maillard reaction during the roasting process.

Lately, melanoidins have been a focus of recent coffee research, due to their color contribution as well as their other chemical properties such as flavor and antioxidant and metal chelating properties.

Although many chemicals present in coffee bean as described, CHAs (1.7–2.4%) and caffeine (0.5–1.5%) are the two most studied coffee chemicals.

others found in green coffee:

Tannin, Thiamin, Xanthine, Scopoletin

(from Putrescine) Spermidine, Spermine,

Ajinomoto patent , another one