Caffeine has been a part of our global history for thousands of years. Each country has its own story and source of caffeine. One of the most eccentric caffeine findings comes from Ethiopia. The folk stories passed between generations says that a farmer, who had recently moved his goats to a new pasture found them to be restless and full of energy. For the next few days, he watched them and noted that they were grazing on small berries. These berries were later dried and called “coffee beans.”
Towards the close of the 16th century, the use of coffee was recorded by a European resident in Egypt, and about this time it came into general use in the Near East. The appreciation of coffee as a beverage in Europe, where it was first known as “Arabian wine,” dates from the 17th century. During this time “coffee houses” were established, the first being opened in Constantinople and Venice. In Britain, the first coffee houses were opened in London in 1652, at St Michael’s Alley, Cornhill. They soon became popular throughout Western Europe and played a significant role in social relations in the 17th and 18th centuries.
Caffeine was first extracted from cocoa beans into its purest form, a white powder, in the 1820s by a German Scientist named Friedrich Ferdinand Runge. Today it is easily extracted and used to make a variety of products that are consumed daily.
Extracting from coffee to produce decaffeinated coffee and a caffeine powder can be done many ways. A few of these processes are no longer used because of the health risks, environmental impact, cost, and flavour changes that were associated with the solvents. Common solvents that were used include Benzene, chloroform, trichloroethylene, and dichloromethane. There are now three main processes that have superseded the use of the previous solvents.
- Water extraction:Raw, green coffee beans are soaked in distilled water for an extended period. The water, containing many other compounds including caffeine and flavour compounds, is then passed through a charcoal filter. The charcoal removes caffeine from the solution, leaving the flavour compounds. The solution is then placed back with the original coffee beans and allowed to evaporate, leaving decaffeinated beans with their original flavour. Many manufacturers collect the caffeine from the charcoal filter and resell it for use in products such as soda and over the counter medications.
- Super-critical Carbon Dioxide extraction:Carbon dioxide, CO2, is a great solvent that is safer than the organic solvents used in previous extractions. The process begins when CO2 is forced through green coffee beans at a temperature above 31.1 °C and a pressure above 73 atm. Under these conditions, CO2 enters a “super-critical “state. In a supercritical state, it has gas-like properties, that allow it to penetrate deep into the beans while maintaining the liquid-like properties that allow it to dissolve 97–99% of the caffeine in the beans. The CO2, now containing caffeine compounds, is then sprayed with high-pressure water to remove the caffeine. This water can then be filtered, and caffeine can be isolated into its purest white powder form.
- Extraction by organic solvents:Research has found certain organic solvents, such as ethyl acetate, that have a lower health risk and environmental hazard than chlorinated and aromatic organic solvents used years before. These solvents are used to dissolve caffeine and are then rinsed away leaving the coffee been decaffeinated.