May 12, 2006
After another sleepless night did you ever think that your so-called caffeine-free coffee may not be all it seems. But, how could you test to make sure the manufacturer’s claim of drug-free cafe latte is based on chemical fact?
Now, US scientists have developed a simple test for caffeine that could be incorporated into a portable device for use in the home to test caffeine levels in all kinds of beverages.
“We envisioned that a simple method to measure caffeine, even in hot beverages, such as coffee, would be of value to individuals and institutions wanting to verify the absence of caffeine,” says Jack Ladenson of Washington University School of Medicine in St. Louis, “This will greatly assist individuals who wish to avoid caffeine.”
Ladenson hopes to develop a simple caffeine test in which test strips that are treated with a specific antibody will react by changing color in the presence of caffeine.
The new test will be designed to be qualitative only: It allows a person to quickly determine whether caffeine is present, but does not indicate the exact amount or concentration of caffeine. In preliminary tests using coffee and cola, an experimental version of the test effectively distinguished caffeinated versions of these products from their decaf counterparts, Ladenson says.
Ladenson’s team hope to convert their antibody-based test for caffeine into a dipstick that could be sold in supermarkets although he confesses that he has no idea when such a kit will be available to consumers or how much it will cost.
Many of us like to avoid the late-night jitters and insomnia that follow a post-prandial espresso, but there are also concerns about the impact of chronic caffeine abuse on long-term health in terms of stress levels and blood pressures. The US Food and Drug Administration also warns pregnant women not to drink caffeine-containing beverages because of the risk of spontaneous miscarriage.
Ironically, the key to the caffeine test comes from llamas and camels – pack animals that have transported caffeinated commodities such as coffee, tea and cocoa for centuries. The immune system of camelids produces antibodies that are resistant to high temperatures common to a nice cup of char or coffee.
The researchers reasoned that if they could create heat-resistant camelid antibodies that reacted to caffeine, they could potentially build a durable assay suitable for use almost anywhere. The most stable version of a caffeine-specific antibody they produced came from a llama named Very Senorita, which worked even after being heated to 90 Celsius, about the temperature of a really hot cup of coffee. Similar antibodies from mice are destroyed at 70 degrees.
The researchers publish details of their test in the journal J Agric Food Chem in June.
For a cool coffee science experiment check out our education section.