Does the caffeine level in coffee vary?
Yes. The length of time coffee beans are roasted affects both their flavor and caffeine content. In fact, the lighter the roast the higher the caffeine content. Because the darker roasts, such as Italian or French roasts, are roasted longer to achieve a dark, rich flavor, more caffeine is lost in the roasting process, resulting in a lower caffeine level than lighter blends.
How much caffeine is in coffee?
After roasting, coffee keeps most of its 0.8% to 2.5% caffeine content. This works out to between 60 and 100 mg. per cup. Compare this to 11 to 115 mg. in a chocolate bar and 80 mg. in a bottle of cola.
How is coffee decaffeinated?
Coffee beans are decaffeinated before roasting in one of two ways. Either the caffeine is chemically extracted with the use of a solvent (which is thoroughly washed out of the beans before roasting) or, using what is known as the Swiss water process, the green beans are steamed and the caffeine-rich outer layers of the beans are scraped away.
What is the chemistry of coffee?
A coffee bean contains 4 to 5% chlorogenic acid, of which 30% to 70% is eliminated during roasting. Coffee beans also have an 11% albumin content which also disappears during roasting. When combined with the chlorogenic acids and carbohydrates, albumin is the agent that gives coffee its dark brown color. Coffee is one of the substances with the highest proportion of aromatic ingredients. Researchers have identified over 700 different aromatic elements in coffee. After roasting, coffee keeps a 0.8% to 2.5% caffeine content. Part of it turns into nicotinamide that acts like a vitamin. A coffee bean also contains 30% to 40% carbohydrate content, the majority of which are polysaccharins as well as 10% to 13% fatty materials that do not disappear with roasting. Coffee beans contain a 10% to 13% water content when green which is reduced to 1% to 2.5% during roasting. Finally, the beans contain about 4% of mineral salts that vary upon origin.