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Coffee (English coffee, Dutch koffie, Arabic kahwa), 1) the same as a coffee tree; 2) the seeds of the coffee tree (coffee beans, or beans), used to prepare a tonic drink known by the same name, and to obtain caffeine from them.
Raw or roasted coffee beans, ground and instant coffee are on sale. To give the beans of coffee collected from the tree, the marketable appearance, they are freed from the pulp, subjected to fermentation, then dried at 50-60 ° C and polished. Caffeine is obtained from raw grains. A coffee drink is prepared from roasted (at 180-200 ° C for 25-30 minutes) and ground beans. When roasting grains, sugar caramelization occurs and substances are formed that give the drink a brown color, pleasant taste and aroma.
There are many varieties of coffee. They are named after the place of production or by the name of the port through which coffee is exported. The best is considered to be Yemeni ("mocha") coffee, produced in small quantities. High quality Brazilian ("santos", etc.) and Colombian (for example, "mama") varieties. Depending on the type of coffee, its chemical composition changes somewhat. The average content of nitrogenous substances in it is 13-14%, caffeine 0.65-2.7, sugar 2-3, fat 12-15, fiber over 20, minerals 3-4%.
Due to the significant content of caffeine, coffee has a stimulating and tonic effect on the central nervous system. 1 teaspoon of ground coffee, usually used to prepare a glass of drink, contains a single therapeutic dose of caffeine (0.07-0.1 g). The coffee drink also stimulates gastric secretions. People with increased excitability of the nervous system, suffering from palpitations, peptic ulcer disease, hypertension, insomnia, a drink made from natural coffee is not recommended.
"Coffee" is also the name for commercially available coffee substitutes made from a wide variety of plant materials (for example, roasted barley, acorns, etc.) that do not contain caffeine. Natural coffee is also added to many coffee substitutes.
People have always argued about whether coffee is harmful to health or not. Once, deciding to put an end to such discussions, the Swedish king Gustav III (who ruled at the end of the 18th century) ordered a very curious experiment. As the object of the experiment, two twin brothers were chosen, sentenced to death. They were sentenced to life imprisonment, but the condition was that one of them would be given a large portion of coffee several times a day, and the other - tea. The rest of their living conditions were equally good. The health of the twins was monitored by two professors. They all waited to see which of the prisoners would be the first to fall ill and die, in order to finally establish which of the drinks was more harmful - coffee or tea. But the twins were in no hurry to die. And it so happened that first one professor died, then another, the king was killed, and both "testers" continued to calmly drink daily "lethal" doses of tea and coffee. The first, at the age of 83, was the one who drank tea.
Since the appearance of coffee in Europe, many myths have been created about it, but even today their number does not decrease.
Coffee causes heart disease. Research over 20 years has found no link between coffee drinking and heart disease, dispelling the myth that coffee raises blood pressure. And for coffee to raise blood cholesterol levels even a little, it must be so strong that few people can drink it.
Coffee has a negative effect on pregnancy. It has been shown that caffeine does not affect fetal development and is not relevant to miscarriage. But according to the latest data, not so long ago published in the American Journal of Epidemiology, pregnant women should still abstain from coffee, as well as from Coca-Cola and other drinks containing caffeine. Their use leads to the fact that the child is born with less weight than the newborns of other mothers.
Coffee causes breast lumps. Scientists continue to deny any relationship between the occurrence of malignant tumors and the use of coffee.
Coffee contributes to the development of osteoporosis. It is believed that caffeine promotes the excretion of calcium from the body, thereby weakening bone tissue. However, research shows: the unwanted effect is fully compensated if; drink a glass of milk a day or make sure that there is a sufficient amount of calcium in the diet.
Coffee is addictive. Doctors (but not all) believe that caffeine is not addictive. However, those who stop drinking coffee or drastically reduce their usual dose are at risk of headaches, think worse, become distracted, irritable or drowsy. All of these troubles can be avoided by gradually cutting back on coffee.
Coffee contains caffeine. It really is. Interestingly, some wild varieties of this plant are caffeine-free. They are now being used to develop new low-caffeine cultivars. In addition, there are brands of instant coffee, from which almost all the caffeine has been specially removed (0.02-0.05% remains). It is washed out with special solvents, and more recently with liquid carbon dioxide from green grains, even before frying.
Coffee stimulates brain activity. In fact, caffeine itself is not a stimulant. But its molecule is similar in shape to the molecule of adenosine, a natural substance found in every cell, which slows down the production of energy in it. It turns out that caffeine temporarily takes the place of adenosine, but since it cannot inhibit energy processes, cells, especially nervous ones, become more energetic.
Coffee raises blood pressure. This is a rather controversial thesis. Those who think so usually cite data from Australian researcher Jack James, published in early 1998. He argued that three to four cups of coffee spread out throughout the day increased diastolic (bottom) blood pressure by 2-4 mmHg. However, the same rise in pressure can be obtained simply from an emotional dispute with a friend. Doctors in other countries have done research on the effect of coffee on blood pressure. For example, British doctors argue that the "hypertensive" effect of coffee is short-lived, and disappears in its usual consumers. And a Dutch study found that 45 coffee drinkers who consumed five cups a day of regular coffee for a long time, and then switched to decaf varieties, had their blood pressure reduced by only one millimeter.
Coffee with milk is difficult to digest. This is not true. Those who hold this opinion argue that milk proteins combine with the tannin found in coffee, and as a result, their absorption is difficult. It is strange that such accusations are not made against tea with milk, whereas tea has more tannin than coffee.
How fresh the coffee can be by looking at it. Oily, glossy-looking coffee is supposedly fresher than dull, dry coffee. In truth, how a coffee looks like is determined by so many factors, including: roast level, oil content, storage and shipping conditions, etc. Only taste and aroma can give a true conclusion.