The seed pit of the coffee plant hides within a dark reddish fruit called a “cherry.” Inside the pit is the coffee seed which resembles a “bean,” hence the name, “coffee bean.” That bean comes in two varieties which depend on slightly different growing conditions, the “Arabica” and the “Robusta,” 80% and 20% of the worldwide crop, respectively.
Coffee beans are picked and processed using either a wet or dry processing to remove the fleshy fruit and pit shell from the seed. The result is “green coffee beans” of varying maturity containing both stable and unstable compounds. They give coffee its flavor characteristics.
Complex Chemistry Simplified
Stable compounds include alkaloids, proteins, amino acids, etc. The alkaloid called caffeine remains stable, whether in green or roasted coffee beans. Other alkaloids may deteriorate with roasting, e.g., theophylline which is present also in green tea, but most alkaloids are stable even after roasting. Coffee proteins typically degrade to amino acids with heat.
About half the weight of the green coffee bean is carbohydrate. The surface of the coffee bean is protected by a number of lipids including diterpenes, an antioxidant linked to protection of liver cells. Other antioxidants are present in green coffee as well, derived from coffee’s chlorogenic acid, which is destroyed if coffee is roasted.
Unstable compounds are also present in green coffee beans. These volatile elements are tied to bad smells, nausea, etc. when used to make a green coffee beverage. These compounds are neutralized by roasting.
Separating the Positive from the Negative
Chlorogenic acid separates green coffee beans from roasted coffee beans. The source for chlorogenic acid must be green coffee beans. Some have suggested that chlorogenic acid assists weight loss, alters fat metabolism, supports diseased hearts, helps ameliorate diabetes, dilates blood vessels to reduce blood pressure, etc. Preliminary research offers limited support for these claims. Further research is advocated by many.
The caffeine component of green coffee is comparable to that found in standard roasted coffee. People who get over-stimulated by caffeine-loaded beverages will suffer from similar complaints when taking green coffee supplements, including nervousness, heart irregularities, headaches, tinnitus, etc. Modest caffeine limits, therefore, are always appropriate.
Green Coffee Supplements
Powders are produced by processing unroasted coffee beans at low temperatures—i.e., the beans are not “cooked.” They are marketed as an aid to enhance metabolism and digestion, and provide that chlorogenic acid, usually described in terms of its antioxidant qualities. Powders may be packaged as powders or pills. Dosing is typically on the basis of comparative caffeine levels found in green tea.
Extracts can be prepared several ways. Just soaking beans in water and extracting the liquid and the chemicals absorbed from the green coffee beans will create an extract. But, think of the variables: How much water was used for the amount of beans soaked? How much evaporation was allowed in the process? How were the components within the extract determined?
Besides not knowing how much chlorogenic acid and caffeine are in the extract, the potency of an extract is undetermined since there is no standard for dosing. Within a given laboratory preparing an extract, there may be a knowledge-based recommended dose, but the suggested dose equivalence to a certain amount of extract equaling a cup of tea, does not really provide sufficient guidance.