Table 3.
Caffeine content (g/L) in a blend of Arabica and Robusta coffee brews.
| Caffeine Content Av ± SD (g/L) |
Methods | Time (min) | Amount of Coffee (g) | Amount of Water (mL) | Type of Water | Volume of Coffee Brew (mL) | Pressure (bars) | Temperature (°C) | Species | Degree/Conditions of Roasting | Type of Coffee | Country | Methods of Analysis | References (Year) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 10.303 | Coffee machine (portafilter, Aurelia Competizione) | 0.4 | 7.5 | Nd | Nd | 25 | 7 | 92 | Robusta blend (95% Robusta + 5% Arabica) | Nd | FG | Nd | HPLC-VWD | [67] (2014) |
| 10.206 | 9 | 92 | ||||||||||||
| 9.171 | 11 | 88 | ||||||||||||
| 8.504 | 7 | 88 | ||||||||||||
| 8.052 | 11 | 92 | ||||||||||||
| 8.038 | 9 | 88 | ||||||||||||
| 6.432 | 7 | 98 | ||||||||||||
| 6.376 | 9 | 98 | ||||||||||||
| 4.448 | 11 | 98 | ||||||||||||
| 1.180 ± 0.100 | Coffee added to hot water, boiling | 3 | 6.9 | 100 | Tap water | Nd | Nd | 95–100 | Arabica and Robusta blend | R | G | Brazil, India, Vietnam, African | SP | [73] (2015) |
| 0.700 ± 0.110 | 3.4 | |||||||||||||
| 2.519 | Pouring water | 2 | 1 g (calculation for 5 g) | 100 | Dw | Nd | Nd | Nd | Arabica and Robusta blend | R | G | Nd | SP | [69] (2014) |
Dw—distilled water, FG—freshly ground coffee, G—ground coffee, HPLC—high-performance liquid chromatography, Nd—no data available, R—roasted coffee, SP—spectrophotometric method.