Formula for Caffein, Showing Its Relation to the Purin Group
Gorter states that caffein exists in coffee in combination with chlorogenic acid as a potassium chlorogenate, C32H36O19, K2(C8H10O2N4)2·2H2O, which he isolated in colorless prisms. This compound is water-soluble, but caffein can not be extracted from the crystals with anhydrous solvents. To this behavior can probably be attributed the difficulty experienced in extracting caffein from coffee with dry organic solvents. However, the fact that a small percentage can be extracted from the green bean in this manner indicates that some of the caffein content exists therein in a free state. This acid compound of caffein will be largely decomposed during the process of torrefaction, so that in roasted coffee a larger percentage will be present in the free state. Microscopical examination of the roasted bean lends verisimilitude to this contention.
Planter's Bungalow with Coffee Trees in Flower, Mysore
Coolies Bagging Coffee on the Drying Grounds
COFFEE SCENES IN BRITISH INDIA
| Table II—Coffee Analyses | ||||||||
| Santos Green | Santos Roasted | Padang Green | Padang Roasted | Guatemala Green | Guatemala Roasted | Mocha Green | Mocha Roasted | |
| Moisture April 20th | 8.75 | 3.75 | 8.78 | 2.72 | 9.59 | 3.40 | 9.06 | 3.36 |
| Moisture September 20th | 8.12 | 6.45 | 8.05 | 6.03 | 8.68 | 6.92 | 8.15 | 7.10 |
| Ash | 4.41 | 4.49 | 4.23 | 4.70 | 3.93 | 4.48 | 4.20 | 4.43 |
| Oil | 12.96 | 13.76 | 12.28 | 13.33 | 12.42 | 13.07 | 14.04 | 14.18 |
| Caffein | 1.87 | 1.81 | 1.56 | 1.47 | 1.26 | 1.22 | 1.31 | 1.28 |
| Caffein, dry basis | 2.03 | —— | 1.69 | —— | 1.39 | —— | 1.44 | —— |
| Crude fiber | 20.70 | 14.75 | 21.92 | 14.95 | 22.23 | 15.23 | 22.46 | 15.41 |
| Protein | 9.50 | 12.93 | 12.62 | 14.75 | 10.43 | 11.69 | 8.56 | 9.57 |
| Protein, dry basis | 10.41 | —— | 13.68 | —— | 11.53 | —— | 9.41 | —— |
| Water extract | 31.11 | 30.30 | 30.83 | 30.21 | 31.04 | 30.47 | 31.27 | 30.44 |
| Specific gravity, 10 percent extract | 1.0109 | 1.0101 | 1.0107 | 1.0104 | 1.0105 | 1.0404 | 1.0108 | 1.0108 |
| Bushelweight | 47.0 | 28.2 | 45.2 | 27.8 | 52.2 | 27.2 | 48.8 | 30.2 |
| 1,000 kernel weight | 103.60 | 120.20 | 167.30 | 151.35 | 189.20 | 165.80 | 119.52 | 100.00 |
| 1,000 kernel weight, dry basis | 119.1 | 115.7 | 154.1 | 147.2 | 171.0 | 160.1 | 108.6 | 96.6 |
| Dextrose | —— | 0.72 | —— | 0.81 | —— | 0.54 | —— | 0.46 |
| Caffetannic acid | .58 | 17.44 | 15.37 | 16.93 | 16.27 | 17.13 | 15.61 | 16.89 |
| Acidity by titration apparent | 1.50 | 2.08 | 1.47 | 2.00 | 1.39 | 2.13 | 1.11 | 1.87 |