The main chemical components 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.
C8H10N4O2 Chemical Structure of Caffeine| Science of Coffee | Website |
| Coffee Chemistry | Home | coffeechemistry.com |
| Harvard : The Nutrition Sources of Coffee | Coffee | The Nutrition Source | Harvard T.H. Chan School of Public Health |
| Coffee and Health | Coffee & Health (coffeeandhealth.org) |
| Coffee Research | Coffee – CoffeeResearch.org |
| World Coffee Research | World Coffee Research | Ensuring the future of coffee. |
| Specialty Coffee Association | Coffee Science Foundation — SCA News — Specialty Coffee Association |
| Science Daily – Coffee | Coffee (sciencedaily.com) |
| Coffee Quality Institute | Home – Coffee Quality Institute (coffeeinstitute.org) |
| Coffee Science Journal | Coffee Science – ISSN 1984-3909 (ufla.br) |