The disputes about the potential hazard of coffee have been staying for years – some equate the benefits of quitting the drink with quitting smoking, while others argue that there is no less caffeine in tea. How are instant and decaf coffee made? Is it true that espresso on an empty stomach can cause ulcers? Should pregnant women completely give up their favorite drink?
Is it true that the stronger the coffee, the more caffeine it contains?
Coffee strength is a flavor profile that does not depend on the caffeine content, so those who choose to cut caffeine can still enjoy a strong espresso. The amount of caffeine in a cup of coffee can be 50–300 mg and depends on the grind size: the finer the coffee particles, the larger the total area of their contact with water, which means that more components can be extracted from them during brewing. Other factors are the duration of contact with water and the initial caffeine content in the beans – Arabica contains almost half as much as Robusta. A cup of decaffeinated coffee still contains it – but just a little, about two milligrams.
Decaffeinated coffee, instant, and capsule – not real, right?
Instant coffee is often not considered “real” due to its questionable taste, but in reality, it is just a concentrate of the coffee solution – and also contains caffeine, unless otherwise indicated on the package. Capsules for coffee machines like Nespresso contain regular ground coffee – and can be caffeinated or decaf. As for decaffeinated coffee, it is also real, and caffeine is extracted from it even at the stage of processing green coffee beans.
This is done in two ways. In one embodiment, green unroasted beans are treated with dichloromethane or ethyl acetate, which removes caffeine from them – these solvents are then removed, also using steam. Although these substances can pose health risks, the final amount in grains is only a few parts per million – so decaf is completely safe. In another case, all components are first boiled out of green coffee beans in hot water; caffeine is extracted from this “broth” with the help of chemicals or special filters, and then a new batch of beans is placed in it. After that, thanks to the effect of diffusion, the solution “draws” only caffeine from the grains, and all other substances, including those responsible for the taste, remain in them.
Is caffeine just coffee, black tea, and cola?
In fact, caffeine is found in the fruits, seeds, and leaves of about sixty plants and protects them from insects – and we do get it mainly from coffee, tea, soda, cocoa, and chocolate. Unfortunately, these products do not protect people from mosquito bites. On average, tea has less caffeine than coffee – 20–80 mg per cup, but not always. For example, a cup of Japanese Gyokuro tea, which has a pale green hue, contains about 500 milligrams of caffeine – five times more than a cup of regular black tea, and two and a half times more than a cup of coffee.
Is it true that coffee raises your heart rate and leads to dehydration?
Caffeine affects the central nervous system – and this leads to a number of effects, psychological and physiological, including the control of muscle contraction and processes associated with sleep. Caffeine raises blood pressure for a couple of hours (not much, by 3–8 mm Hg) and raises the heart rate. Although caffeine is a mild diuretic, it does not contribute to dehydration despite popular myth.
Low doses of caffeine (20-200 mg per day – that is, up to three cups of coffee) improve mood, focus, energy, and sociality, but the systematic use of too large doses (1500-2000 mg per day – that is, somewhere around 15– 20 cups) is associated with anxiety, tremors, sleep disorders, and other neuropsychiatric disorders.