Text 3a Carbohydrates

For such activities as breathing, the heartbeat, the maintenance of body temperature and others any person needs energy. We can get it from protein, fat, alcohol. But from carbohydrates we get most of the energy that we need. There are three major groups of carbohydrates in food: sugars, starches, cellulose and related materials. They all are compounds of carbon, hydrogen and oxygen and their chemical structures are based on a common unit (as a rule it is glucose). These units can be linked together in different ways and in different numbers. Classification of carbohydrates depends on the number of such units.

Sugars and starches are a major source of man s food energy all over the world.

Glucose, fructose and galactose are monosaccharides (or simple sugars), and they are the units of more complex carbohydrates. Glucose occurs in fruit and plant juices and in the blood of living animals. During digestion most carbohydrates in food convert to glucose. From partial hydrolysis of starch we can get glucose syrups (or liquid glucose). Fructose occurs in some fruit and vegetables and especially in honey. It is the sweetest sugar that we know. Galactose does not occur in the free state, but it forms part of lactose.

Disaccharides consist of two monosaccharides linked together. They are sucrose, maltose, and lactose. Sucrose is a chemical combination of glucose and fructose. "Sugar" is a pure sucrose. Maltose is a combination of two glucose units. It is formed during the breakdown of starch by digestion. Lactose is a combination of glucose and galactose. It occurs only in milk.

Text 3b Sugars and Non-Sugar Sweeteners

The main sources of sugars in the diet are sugar, sweets and chocolates, milk (as lactose), fruit: and fruit products, biscuits and cakes. All sugars dissolve in water and are differently sweet in taste. Sugars usually form white or colourless crystals when the water in which they are dissolve becomes supersaturated.

Sugars are sources of energy and sweetness. Bui also they are used in jam-making, canning and freezing as preservatives. In biscuits, cakes, soft drinks and some other foods they help to provide their characteristic texture.

Besides there are some other substances which also taste sweet. Sorbitol and mannitol, which are made from glucose or sucrose, are sometimes used in diabetic foods because they are absorbed slowly. However, their energy value is as large as that of glucose. In contrast, saccharin has no chemical or nutritional relationship to sugars and provides no energy.

Non-sugar sweeteners do not rank as foods, but they may be used as sweetening agents when it is necessary to make the amount of sugars in the diet smaller.

Unit 4

Вивчіть подані слова i словосполучення

number – число, номер

a number of – деяка кількість

compose – складатися

to be composed of – складатися з

exist – існувати

flour – борошно, порошок

potato – картопля

eat,ate,eaten – їсти

raw – сирий, недоварений

gelatinize – перетворюватися на холодець

break, broke, broken – розбивати(ся), руйнувати(ся)

tobreakdown – руйнувати(ся), ділитися на частини

root – корінь

turnip – ріпа

stiff – тугий, негнучкий

jelly – желе, холодець

although – хоча, незважаючи на те що

tooth decay – руйнування зубів

disease – хвороба

bowel cancer – рак кишечника

intolerance – нетерпимість