Coffee has been studied on various occasions for many years now. It is perhaps the most studied drink in the world...
In the past, it had a rather undeservedly bad reputation, with doctors tending to frown upon habitual drinkers. Today, however, it enjoys new fame. We now know for certain, for example that coffee is far from poisonous. A rather amusing anecdote tells the eighteenth century story of king Gustav III of Sweden, who chose to inflict the death penalty by means of massive doses of coffee. The fortunate victims not only did not die, but lived to a ripe old age.
Science has now clarified many aspects of coffee and the way it can affect our health.
Technically, coffee is a concentrate of hundreds of different substances. The distribution of these substances varies from species to species, and some may even by typical of one variety, and entirely lacking from another. Many are ‘bioactive’, i.e. with a specific role in cell metabolism, such as mineral salts like potassium, for example, vitamin precursors such as trigonelline, antioxidants such as tannins, melanoidins, and, of course, most famous of all, caffeine: a blandly stimulating alkaloid.
Coffee beans are actually the seeds of an evergreen plant from the Rubiaceae family, genus Coffea. There are around eighty different species comprising the Coffea genus, but two are particularly important on a commercial level: Coffea Arabica, known as ‘Arabica’, and Coffea Canephora, known as 'Robusta'.
The two species are not only different in terms of quality, but also as concerns their chemical composition. Arabica contains far more lipids and other substances such as trigonelline, whilst Robusta contains more caffeine and chlorogenic acids.
The composition of the coffee changes to a certain extent during roasting, the heating process that changes the raw green coffee beans into roasted beans. During roasting, some substances change, whilst others disappear and yet others are formed.
At the start of the roasting process, the green coffee reduces in volume, until the beans reach a temperature of 160°. Carbon dioxide is then formed, with a consequent organic loss, and the beans swell and reduce in density. At this temperature, hundreds of volatile substances form - giving rise to the classic roasted coffee aroma - together with the brown pigment - the melanoidins. Above 200°, the chemical reaction becomes exothermic, and if 250° are exceeded, the bean begins to burn, forming soot.
Caffeine
Caffeine is, without a doubt, the most famous substance contained within coffee. From a chemical point of view, it is an alkaloid (specifically, a 1,3,7 trimethylxanthine), that is not only found in coffee, but is also present in other popular drinks, such as chocolate, tea and non-alcoholic cola based drinks, though in lesser quantities.
The pharmacological function of caffeine has been well and extensively defined. It was discovered and isolated approximately 180 years ago by the German chemist Ferdinand Runge, and we now know that high doses (significantly more than that contained in a cup of coffee), caffeine can also act as a painkiller.
Caffeine has a very brief life in our organism, and there is absolutely no risk of accumulation. It is absorbed in the intestine, with maximum concentration levels reached in the blood after 15-45 minutes. After this, it gradually decreases until disappearing completely in just a few hours.
Recent studies have shown the benefits of coffee on the whole organism.
A cup of coffee makes you feel more alert, active and energetic. These positive results are all thanks to the caffeine, which stimulates concentration, reawakens mental faculties, charges the memory and relieves headaches (ref.). It also dilates the bronchi, helping you to breathe more easily. And that is not all, coffee also helps you digest, because it increases production of gastric fluids and liver bile.
We should also perhaps mention that coffee is much more than just caffeine, also containing antioxidants to help fight against the free radicals and cell damage. These same antioxidants can also lead to weight loss, as they encourage thermogenesis, or the consumption or calories for various organic functions, thereby accelerating your metabolic rate.
And apart from these, it is important to realise that coffee contains literally hundreds of other biologically active molecules (polysaccharides, lipids, phenol composites and minerals such as potassium and magnesium). And this is why it is so important to remember, and not to confuse, the effects of caffeine with those of coffee.
