Английский язык. Профессиональное общение специалистов в сфере технологии продовольственных продуктов и потребительских товаров. Учебное пособие

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2. Найдите ошибку.

1. This procedure ensures that the oil will not partial solidify in the A B C D

refrigerator.

2. Trace metals may promote oxidation within the oil and shorten their A B C D

shelf-life.

3. Then perfume are added while the soap cools. A B C D

4. Refined removes traces of certain nutrients. A B C D

5. The Blaw-Knox Rotocell is used to be met the demands of oil in- A B C D

dustry.

3. Составьте предложения из указанных слов.

1.Soaps, sodium, for, used, hydroxide, household, is.

2.To remove, salt, the mixture, the glycerin, added, to, is.

3.In, water, several, salty, soap, is, washed, mixture, the, times.

4.Is, oil cake, by, the, processed, extraction, solvent.

5.Seeds, and, be stripped, nuts, must, and, dehulled.

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КЛЮЧИ

Test 1

Задание 1

1 - A; 2 - D; 3 - B; 4 - C; 5 - D; 6 - D; 7 - B; 8 - A; 9 - C; 10 - D; 11 - D; 12 - A; 13 - C; 14 - B.

Задание 2

1 - B (as soon as possible); 2 - C (by); 3 - B (separated); 4 - A (neutralized); 5 - C (is).

Задание 3

1.Butter is made from milk or cream with salt and coloring agents.

2.Fat is the foodstuff which possesses the greatest caloric density.

3.The olives are separated from any foreign material and ground to a fine paste.

4.Butter fat differs from other animal fats in the number of triglycerides.

5.Low-fat diets prove to be very unappetizing.

Test 2

Задание 1

1 - B; 2 - A; 3 - D; 4 - B; 5 - A; 6 - C; 7 - D; 8 - C; 9 - D; 10 - A; 11 - D; 12 - C; 13 - B.

Задание 2

1 - C (have); 2 - D (be); 3 - B (that); 4 - A (this); 5 - B (give).

Задание 3

1.We expect this kind of margarine to be popular.

2.Consumers prefer to buy olive oil.

3.The fatty product to be used for cakes is called pastry margarine.

4.Fatty products are said to be required in small amounts.

5.To use a liquid soap is easy and simple.

Test 3

Задание 1

1 - C; 2 - B; 3 - D; 4 - D; 5 - A; 6 - C; 7 - B; 8 - A; 9 - C; 10 - D; 11 - B; 12 - B; 13 - A.

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Задание 2

1 - A (are); 2 - B (by); 3 - C (the cheapest); 4 - B (separated); 5 - C (has).

Задание 3

1.People began to process vegetable oils thousands of years ago.

2.Corn oil first became available in the 1960-s.

3.Cooking oil consists of edible vegetable oils derived from many plants.

4.The first patent for extraction of oil using solvents was obtained in England.

5.Changes in fat can be detected by smell and taste.

Test 4

Задание 1

1 - B; 2 - D; 3 - C; 4 - A; 5 - D; 6 - B; 7 - B; 8 - A; 9 - D; 10 - C; 11 - B; 12 - A; 13 - D.

Задание 2

1 - С (partially); 2 - D (its); 3 - B (is); 4 - A (refining); 5 - C (to meet).

Задание 3

1.Sodium hydroxide is used for household soaps.

2.Salt is added to the mixture to remove the glycerin.

3.The soap mixture is washed several times in salty water.

4.The oil cake is processed by solvent extraction.

5.Nuts and seeds must be stripped and dehulled.

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ТЕКСТЫ ДЛЯ ДОПОЛНИТЕЛЬНОГО ЧТЕНИЯ

Text 1

1. Прочитайте текст 1. Что вы можете сказать о составе жиров и процессе их усвоения организмом человека. При переводе используйте слова, данные после текстов (стр. 133-136).

ROLE OF FATS

The nutritional values of proteins, carbohydrates, vitamins, their metabolism in accurate detail, their contribution to the growth, repair and health of the body - these have been well understood for a very long time, but the same cannot be said of fat. What happens to it ingested and utilized from the body’s fat depots, its metabolism is less well understood and most of what is known is of fairly recent history.

There must be many survivors of the older fields of medicine who remember the later unraveling stages of fat metabolism, although it cannot be said to be completely understood even in this day and age. A prominent researcher in the field in those early days was Professor Fraser, professor of physiology at Birmingham University and a graduate of St. Mary’s London. He made an annual return to his alma mater to deliver a lecture on Fat Metabolism, to staff and students, and not unexpectedly suffered the sobriquet among the rough elements of the student body, of «Fats». He was, in fact, heavily built, corpulent. Each year his lecture, including a description of his own work, brought us a little nearer to a better understanding of the behavior of fat in the body.

Composition

Fats are esters (glycerides) of glycerol and fatty acids, which form esters with one, two or three of its hydroxyl groups; they are mainly triglycerides and natural fat is various mixed triglycerides. The differences in appearance of the fat of different animals are due to the varying proportions in which these mixed glycerides occur. Adipose tissue consists almost exclusively of fats derived from oleic,

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stearic and palmitic fatty acids and according to the amounts of the acids present the fat may be solid at body temperatures, e.g. mutton fat, or containing much olein, remaining fluid. Milk fat is the one animal fat which contains large proportion of the lower fatty acids, e.g. butyric, 5 %.

Fats are insoluble in water; if heated with steam, treated with dilute alkalies or acted upon by enzymes, they undergo hydrolysis and split into molecules of fatty acids and one molecule of glycerol. This action occurs in stage, the removal of one fatty acid results in a diglyceride, two molecules of fatty acid, monoglyceride. The process may occur spontaneously when fat is exposed to the air; it has an increased value and is described as rancid.

Modern appreciation of dietary predisposing causes of disease in man has led to an important compositional classification of dietary fat, a division into saturated and unsaturated fats, according to whether or not the carbon bonds of the fatty acids were taken up, according to the homologues series with the following formulae - saturated fatty acids, C2H7COOH. Animal fats usually have sixteen or more carbon atoms; those carbons not engaged to a radicle are termed unsaturated. Some of the high fatty acids have a relatively large number of carbon atoms without radicles. Most of the fats with unsaturated fatty acids are among the numerous vegetable fats and oils. Unsaturation plays an important part in the physical reactions of the fact; the proportion to which it exists in dietary fat has assumed significance and is recommended in preference to saturated fat because of the latter’s association with causes of cardiovascular disease. A recommended ratio of unsaturated fat to saturated fat in the diet is 2:1.

Fat Metabolism

This covers the metabolism of all the compounds which contain fatty acids. Fat is the only nutrient which amasses stores within the body-depot fat mainly. It is the main reserve in periods of undernourishment or starvation and occurs as triglycerides of various fatty acids, the chief of which are stearic, palmitic and oleic. Ordinary depot fat contains about 75 % oleic acid. Not all fats in food are acceptable to the palate and stomach; some fats, especially when, warm, soft and semi-gelatinous, such as mutton fat, bacon fat, are repellent to many people, especially children, causing nausea,

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wretching and vomiting. The same fats, however, may be accepted when cold. Ingested fats remain in the stomach much longer than other nutrients of normal composition and texture, giving a sensation of satiety. They are accordingly said to «satisfy hunger». The exception being coarse, grained, tough foods, such as some meat, which may remain in the stomach for abnormally long periods before it is sufficiently macerated, softened, to pass through the pyloric sphincter.

Digestion of fat does not take place in the stomach; conditions are unsuitable for the emulsification which must precede digestion. It is not until the fat reaches the lower duodenum, below the point at which the pancreatic juice and bile enters, that emulsification is possible, to fine particles, necessary before digestion and absorption can take place.

Emulsification is initiated by bile salts, fatty acids in small quantities, and monoglycerides liberated by pancreatic juices, pH 6,0 to 8,5, with the formation of droplets. Pancreatic and intestinal juices both contain lipase which splits triglycerides into fatty acids, diand mono-glycerides, and glycerol. The final result is a clear microemulsion, which passes into the cells of the intestinal mucosa, where the droplets can be seen as minute particles under electron microscopy. Further hydrolysis may take place and new triglycerides form from fatty acids brought by the circulation. These are mixed so that the newly formed triglycerides are not the same as those in the food ingested. The function of this reformation is to present the body with fats (lipids) in the form it needs. Similar restructuring occurs with proteins. Most of the fat absorbed in the intestines enters the circulation through the thoracic duct; a small part may reach the liver through the portal circulation.

After absorption, fats (and other nutrients) must be transported in the blood to storage depots or to the muscles and other tissues. An adult diet with up to 100 g./day of fat is digested and absorbed, with no more than 7 g., daily in the faeces, but larger quantities, up to 250 g.,/day can be absorbed if the body is short of energy. This is the explanation of the utilization of excess fat which in years past was a regular feature of the adult diet; heavy manual work, greater and more sustained effort in the daily lives of people accounted for the excess fat and the infrequency of overweight. They used it up; later slothful generations have allowed it to accumulate. Nutrients must

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pass to and from the liver (as well as other tissues), where chemical transformation takes place. Unlike carbohydrates, e.g., lipids do not have a single currency for transport, i.e., glucose, and must be carried as complex lipoprotein of varying density, and include chylomicrons and also free fatty acids which are bound to blood albumin.

Cholesterol

Cholesterol has an important role - the transport of lipids in the blood. Sterols, a widely distributed and important group of substances involved in fat metabolism, all have the same basic ring structure. The blood level of cholesterol is considered an important factor in the prevention of cardiovascular disease. It is present in all foods of animal origin, with egg yolks being particularly rich. It is not present in foods of vegetable (plant) origin.

The main source in which cholesterol is excreted is through the action of bile salts in the digestion of fat; it is raised only slightly in the blood after a fatty meal. From epidemiological studies in the USA and other Western nations, there are marked variations in cholesterol concentration. The mean concentration in adults of 45 years is 234 mgm/100 ml in males; a little less in younger age groups of females, and much less where there is poverty. Plasma concentrations are in part dependent on age. Unless large quantities of fat are ingested, dietary cholesterol has little influence on the plasma concentration.

Dietary Fat

In the western world, the most affluent of the population derived about 40 % of their energy requirements from dietary fat. That cholesterol serum levels are closely related to fat intake, although the intake and needs vary greatly. The form in which fat is taken varies with the degree of affluence of people; in greater quantity, richer and more animal fat in the prosperous, such as butter, cream and other dairy fats; including cheaper varieties of nuts and eaten most sparingly, in poorer peoples. This is seen as largely responsible for the increased incidence of fat associated disease in the former. Fat conversion (from carbohydrates) is also greater in states of affluence; the people consuming much more sugary food.

After a meal containing fat, large numbers of chylomicrons appear in the blood. They are removed from the blood rapidly if only small amounts of fat are ingested, say up to 30 g., but if large

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amounts of fat are eaten, the blood lipids increase, the plasma may become milky. This means that areas of the body with a large blood supply, especially the abdominal organs - the liver, mesentery portal circulation, especially - and little effort is made to use the lipids as energy, a massive lipaemia may build up and remain there. An example is crouching over the wheel of a car in driving for long periods after heavy meals; an isolated factor in a complex process which has done harm to health and increased the risk of cardiovascular accidents, in such postures as this almost one-quarter of the whole blood supply of the body is in the abdomen, with its fat-rich laden circulation from the intestines and in the portal circulation.

Fat conversion

The conversion of carbohydrates into fat within the animal body has been known for many years; it was discovered mainly from the feeding and fattening of stock animals. Animals will fatten on a diet rich in carbohydrates and relatively poor in fat. Experiments have shown that of the total increase in body fat 6/7 consisted of synthesized fat, with high carbon content. The fat is harder than other fat, and whiter.

The actual process by which sugars are converted into fat is not completely known. That the conversion occurs in humans is all too obvious; avoidance of sugar and sugar confections forms the chief form of slimming. Although a high proportion of proteins amino acids can be converted into carbohydrates in the body, the process ends there. It is certain that fat does not normally arise from protein; as well as the limitations, the process would be extremely slow. Next in importance to the triglycerides are the phospholipids, of which there are great varieties in the body. They occur mainly in the blood and tissues, form part of cell membranes and are concerned in the transport of fat about the body. Lecithin is one of the important phospholipids in the plasma. Most phospholipids are characterized by a high proportion of unsaturated fatty acids.

Concentrated fat in stock animals is said to be firmer than normal but in people who eat large quantities of sugary confections, their flabby appearance does not suggest this. Most diets supply far more fat than is necessary for the physiological needs; even in impoverished and under-nourished areas, it contributes 15 % of energy requirements; in war-time Britain, it was never below 33 %. Notwith-

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standing this, many minor ailments were attributed by responsible opinion to the low fat intake, but were more likely due to insufficiency of the fat-soluble vitamins, and insufficiency of protein which invariably accompanies low fat intakes. Deficiency in fat in the diet of even under-nourished but otherwise healthy people is exceedingly rare; when it occurs, metabolic abnormalities are the main cause, non-absorption, in conditions of steatorhoea, where ingested fat passes out in the faeces.

Certain fatty acids are essential and are now known to be the form in which fat enters the blood from the storage depots in adipose tissue, a fraction of about 5 % which is carried round the blood bound to the plasma albumin. The concentration of these essential fatty acids is extremely sensitive to the nutritional state.

Fat in Disease

Large quantities of the derivatives of certain products of lipid metanlosim result in the condition Ketosis. Acetoacetic acid is the principal source of kitones and the disturbance of acid-base balance. Patients with ketosis have a sweet, sickly-smelling breath; it is a result of a number of abnormal conditions and diseases.

Personal observations, morbidity and mortality statistics, from limited localized surveys to large-scale population studies over the past few decades leave no doubt of a causative association between fat and cardiovascular disease, ranging from simple atherosclerosis to the heart itself; to what used to be more descriptively referred to as «fatty infiltration» of the myocardium. As in other dietary etiologies it does not act in isolation; and there are other important causative associations, the chief being excessive cigarette smoking, and insufficient exercise. The last is probably the sole explanation of why past generations ate without harm heavy, fatty meals, almost entirely animal fat consumption continued into old age; the latter the meat, the more they relished it. Even in old age, they were obliged to regularly exercise themselves to a much greater extent than today, considerably more walking and many an octogenarian cultivated his garden and dug his «praties». In terms of human health, the biggest enemy to the present day is probably the motor car.

A more detailed classification of fats has been used to identify hazards, the most widely used is the division of fats into saturated (animal) and unsaturated (mainly vegetable). The last being respon-

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sible for higher cholesterol levels in the blood and bile, excess is considered to influence the incidence of atherosclerosis and cardiovascular disease. It is abundantly present in eggs, to a lesser extent, in cream. Excess esters of cholesterol are thought to adhere to the intimate wall of blood vessels (There are other causes of atheromaage hypertension diabetes) but in raised blood cholesterol, atheromatous degeneration may be severe. Cholesterol lesions are common in areas of strain. There is no conclusive evidence that food rich in cholesterol has any marked effect on blood cholesterol levels or that a cholesterol free or low diet is a means of prevention but the belief that it has beneficial effects is strong; and blood lipid concentrations have been shown to be indirectly related to fat consumption. Many studies are being made in relation to coronary artery disease.

Fat intake in individuals and small sections of populations has, much more than in larger studies, been shown to have a causal association with that other «killer disease» - cancer. It is being increasingly referred to as a strong possible cause of cancer, particularly of the colon and the breast. Strongly positive correlations with consumption of fat per head have been obtained. These forms of cancer have increased significantly in the Japanese who have consumed fat at Western diet levels. The reports however vary in different countries. In Canada and various parts of the USA the reports demonstrated a positive relationship between fat intake and cancer among the vegetarians of the Seventh Day Adventist, who have a fat consumption comparable to the average, show a low incidence of breast cancer, also colonic cancer; and similarly among the Mormons.

Support of a relationship between cancer and fat in men has a variable and indeed crude type of evidence. There is evidence that certain fatty residues in human faeces resemble substances that are carcinogenic in animals. Studies into coronary heart disease has shown differences in different parts of the world, fats are complex substances and the same could very well apply to a relationship with cancer.

Diseases of the alimentary tract at digestion have local differences; e.g., duodenal ulcer is much more frequent in south-east England than gall bladder disease, but in Cornwall, where fat (and most animal fats) has a higher consumption, duodenal ulcer has a lower incidence than cholecystitis and gall-stones.