What is decaf coffee, what you need to know about decaf coffee
1. What is Decaf coffee?
Decaf coffee stands for decaffeinated coffee, meaning that coffee has been removed up to 97% caffeine.
In the past, many people were quite skeptical when using decaf coffee for fear of the impact of organic solvents in decaffeinating process will adversely affect health.
However, at present, decaf coffee is known as a premium drink for coffee lovers but allergic to caffeine.
2. General principle of decaffeinating process.
There are many different methods of decaffeination being used. But generally these processes are done on green (unroasted) green coffee. It usually starts with the process of steaming coffee; then soaking in solvent to extract caffeine (while other components are not affected much). This process is repeated many times until the caffeine content meets the required standard (eliminates 97% of the caffeine – according to US standards, or 99.9% according to EU standards).
3. History of caffeine reduction process
The first commercially successful decaffeinating method was invented by German merchant Ludwig Roselius and colleagues in 1903 (patented in 1906). This initial decontamination process involves steaming coffee beans with a variety of acids or bases; then using benzene as a solvent to remove caffeine. Decaffeinated coffee in this way was sold under the name Kaffee HAG under the company name Kaffee Handels-Aktien-Gesellschaft. However, due to health concerns related to benzene (recognized as a carcinogen), this method was soon removed.
Although today is no longer any manufacturer using this method; but most modern methods reducing caffeine are conducted in a similar manner. In it instead of using benzene solvents, the scientists used dichloromethane and ethyl acetate
4. Caffeine reduction methods
4.1. Method of organic solvents
In the process, if the coffee is soaked and heated directly in the solvent environment (direct solvent), the flavors will easily diffuse according to caffeine). So an alternative method has been to be applied; it is to soak coffee in hot water first and then switch to the solvent environment (indirect solvent). This way the solvents will absorb most of the caffeine.
For organic solvents, the U.S. Food and Drug Administration (FDA) limits methylene chloride to less than 10 parts per million (0.001%) of decaffeinated roasted coffee. But because methylene chloride can lead to the risk of some cancers; there is some concern about the use of this solvent. Meanwhile, Ethyl acetate (EA) is usually derived from fruit or sugarcane. So it is much safer, but the problem is that EA also has a characteristic smell and can remain in coffee after reduction caffeine.
4.2. Swiss Water Method Technical Method
In fact, water is not the best way to eliminate caffeine because they can wash away the important compounds of coffee beans. However, a more advanced process has helped overcome this, by combining the extract water without caffeine and activated carbon. This method was first used in Switzerland in 1933, and commercialized in 1979 should be popular as Swiss Water.
In this method, the beans are soaked in hot water and then added to a decaffeinated green coffee extract mixture (water that has been saturated with coffee solutes from previous extraction cycles). . Due to the difference in concentration, the caffeine in the seeds will leach out and dissolve in the extract. The extract solution continues to pass through activated carbon, to eliminate caffeine and can be reused later. Economically, this method is more expensive than the solvent method because the extracted caffeine cannot be recovered and sold separately.
The diagram also shows a “French water decaffeination” technique, also conducted by soaking coffee in hot water, (for up to 24 hours). Then the coffee is dried, while the water is passed through the carbon filter to remove the caffeine. This Water does not contain caffeine, but rich in flavor are then reabsorbed by the dry coffee. So coffee can get back some flavor that has been lost before being dried and roasted.
4.3. Decaffeination by supercritical carbon dioxide method/b>
Recently, food scientists have turned to supercritical carbon dioxide as a much safer and more effective means of Decaffeination.
This technique was developed by Kurt Zosel, a scientist at the Max Planck Institute (Germany). In this process Supercritical Carbon dioxide (sCO2), ie liquefied CO2 at 31 ° C under pressure of 74 bar; is pressed through green coffee beans to collect caffeine; then sprayed into water to “release” caffeine.
With the stability of sCO2, this process takes place at a lower temperature allowing to minimize the denaturation of other components of coffee; and caffeine can be isolated and collected for other purposes.
The process is highly selective, but the downside is that it is expensive because it requires industrial equipment to be subjected to pressures over 150 bar with temperatures around 70 ° C; not to mention the use of large amounts of CO2 with Complex recall systems and other technical aspects.
5. The amount of caffeine still exists in decaf coffee.
5.1. Quantitative method of caffeine
To ensure product quality, manufacturers are required to test new decaffeinated coffee beans to ensure that the caffeine concentration is relatively low. A reduction in caffeine content of at least 97% is required by US standards. There is less than 0.1% caffeine in decaffeinated coffee and less than 0.3% in decaffeinated instant coffee in Canada.
To do so, many coffee companies choose to use high-performance liquid chromatography (HPLC) to measure the amount of caffeine remaining in the bean. However, because HPLC can be quite expensive, some coffee companies have begun using other methods such as near-infrared spectroscopy (NIR).
Although HPLC is highly accurate, the NIR spectrum is much faster, cheaper and generally easier to use.
Finally, an unusual method used to quantify the remaining caffeine involves the UV visible spectrum; which can be very advantageous for decontamination processes including supercritical CO 2; because CO 2 does not Absorb in the range of UV-Vis.
5.2. The caffeine content still exists in decaf coffee.
A controlled study of ten decaffeinated coffee samples prepared from coffee shops showed that there was still some caffeine. Fourteen to twenty cups of decaffeinated coffee thus contain as much caffeine as a regular cup of coffee. Coffee samples of 473 ml (16 ounces) contain caffeine in the range of 8.6 mg to 13.9 mg.
In another study of popular brands of decaf coffee, the caffeine content varied from 3 mg to 32 mg. A regular cup of coffee has a capacity of 237 ml (8 ounces) containing 95 – 200 mg of caffeine; and a cup of Coca-Cola 355 ml (12 ounces) contains 36 mg.
Both studies tested the amount of caffeine in store coffee; showing that the caffeine that might be left over from normal coffee is served instead of poorly decaffeinated coffee.
6. Health effects of Decaf coffee
Similar to regular coffee, Decaf coffee contains antioxidants – mainly hydrocinnamic acid and polyphenol compounds; although they can be 15% lower due to the loss of caffeine.
Antioxidants help neutralize harmful compounds, help reduce damage and prevent diseases like heart disease, cancer and diabetes.
A cup of Decaf coffee contains 2.4% Magnesium, 4.8% Potassium and 25% Vitamin B3. Because of the low caffeine content, you can use 2-3 cups / day to increase nutrition from Decaf coffee.
Decaf coffee is similar to regular coffee, the main difference being its low caffeine content. Therefore they are suitable for those who feel cold, easy to react with the bitter or caffeine in regular coffee.
Source: Compiled from wikipedia
See also: Robusta coffee and Arabica coffee: What’s the difference?