Английский язык. Учебное пособие для студентов направления подготовки бакалавров 151000 «Технологические машины и оборудование» (профиль «Машины и апп
.pdf2. Form words with the given prefixes and translate them into Russian:
OVER - : heat, flow, estimate, load, weigh, work
UNDER - : do, go, take, line, ground, graduate, estimate, load.
3.What is the meaning of the prefix INTER -? Translate the words: international, interaction, interdependent, interchange, interconnection.
4.Translate into Russian:
low water vapour pressure, high liquid content, freeze-dried product reconstitution properties, vacuum freeze drying, poorly conducting material, relatively large heat exchange surface, water-rich products concentration.
5. Translate the following sentences paying attention to MODAL VERBS and their equivalents:
1. The condenser has to be cooled to a very low temperature. 2. All factors should be taken into account when choosing suitable equipment. 3. This process can take place under high pressure. 4. While carrying out this operation the reacting materials are to be brought into close contact. 5. One should be careful while working with infrared radiation. 6. Another feature that might be considered an advantage is that very low water contents can be obtained. 7. In vacuum freeze driers large volumes of air and water vapour have to be removed.
II. Skim Text 14B and try to understand what is about and what information is known to you.
Text 14B
PRESERVATION OF FOODS
Refrigeration is widely used as a means of maintaining the low temperatures found satisfactory in the storage of perishable foods. Fresh milk, meat and similar foods keep best just above the freezing point. Certain fruits and vegetables also keep better when cold, low temperatures extend the keeping period for both underripe and ripe fruits by reducing the enzyme action which causes ripening of underripe fruits and frequently the spoilage of ripe fruits.
Studies indicate that during storage, whether common or cold fresh vegetables and fruits may undergo changes in flavoury texture, and food value. The extent of these changes depends upon the length of time during
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which they are stored and the conditions under which they are held. The vitamin content may be significantly decreased. This is especially true of ascorbic acid.
Freezing, like cold storage does not destroy the microorganisms and enzymes present in foods. It makes them more or less inactive, however, so that frozen foods, when held in the proper temperature, undergo changes slowly. This applies to the nutritive value as well as to other chemical and physical characteristics. Fish, poultry meat, vegetables and fruits are preserved by freezing.
Removal of moisture is of benefit in preserving food. Although it is difficult to dry foods to the point of destroying microorganisms, it is comparatively easy to dry foods so that no spoilage takes place. Drying of foods to prevent spoilage does not necessarily mean complete removal of the water, but it does mean concentration to such a point that the liquid is denser than the body fluid of the organisms. Hence, although the water is present in the food it may not be available to the organisms which might cause spoilage. Drying may retard enzyme action also, but in vegetables, especially the effect of enzymes is sufficient to cause comparatively rapid deterioration. Drying alters greatly the character of the food.
EXERCISES
1.Identify the topic of each paragraph of Text 14 B.
2.Answer the following questions and discuss them with your fellowstudents.
1.What products are preserved by the refrigeration?
2.What changes may undergo cold fresh vegetables and fruit during storage?
3.Does freezing destroy the microorganisms and enzymes present in foods?
4.Does drying of foods mean complete removal of the water?
5.Is it difficult to dry foods?
3. Give a brief overview of the structure and contents of Text 14 B
using the following expressions.
The subject of the text is ...
The text deals with ...
It is pointed out that ...
It is obvious that ...
According to the text…
To sum it up ...
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UNIT 15
I. Read and memorize the active vocabulary to the text. Read and translate Text 15A .
dilute - разбавлять
evaporation - испарение, выпаривание, сгущение expression - выжимание, отжим
freezing-out - вымораживание hexane - гексан
liquor - раствор, сироп
microbial spoilage - бактериальная порча partition - разделение
phase equilibrium - равновесие фаз powdered milk - сухое молоко solute - растворенное вещество solvent - растворитель
sugar cane - сахарный тростник volatility - летучесть, испаряемость
withdrawal - выведение, извлечение, удаление
Text 15A
CONCENTRATION AND CRYSTALLIZATION
Concentration is the withdrawal of some of the solvent from a solution, and it is thus a partial separation of a homogeneous mixture of solute and solvent. The partial separation results in a more concentrated solution. In the food industry the solvent to be withdrawn is nearly always water.
Concentration is applied to water-rich liquid products which are either directly available in such a state (milk, blood) or are obtained by expression (sugar cane liquor, fruit, vegetables) or extraction (extracts of coffee, tea, meat etc). An axample of the application of the concentration process to a nonaqueous solution is the concentration of a solution of oil in a solvent such as hexane.
Withdrawal of a large portion of the water from a product reduces the storage and transportation costs. Water has to be added to the concetrate again prior to consumption. Concentration is widely used for food preservation. It is known that an increase in the concentration of sugar has a
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preservation action. When products contain a great deal of sugar by nature, then concentration can be used to lower the water activity to such an extent that they become microbiologically stable. If the amount of sugar present is insufficient then more sugar can be added. In the manufacture of jam, for example, concentration is used as well as addition of sugar. It is also possible, for example to concentrate a meat extract containing salt to such an extent that there will be no further microbial spoilage.
Concentration is also often used as a treatment prior to a more complete withdrawal of water (drying). An important example is the preparation of powdered milk in which the milk is first concentrated to a solid content of 45 to 50 % and then dried further. In the sugar industry concentration is used as pretreatment in the crystallization of sugar. In the wine industry concentration is sometimes used to raise the alcohol content to a prescribed level.
The process of concentration can be carried out by any one of the following physical methods. It is possible to utilize a difference in partition between two phases, i.e. a phase equilibrium favourable for separation. In evaporation use is made of the difference in volatility between water and solute and thus a favourable liquid-vapour equilibrium. In freezing-out, use is made of the fact that dilute solutions are in equilibrium with ice at their freezing points; thus a favourable liquid-solid equilibrium is utilized. In freezingout part of the water is crystallized by withdrawal of heat, whereupon the concentrated solution is separated mechanically from the ice crystals.
In crystallization process part of the solute in the homogeneous solution is converted into crystalline state and the crystals are separated mechanically from the remaining solution. The great advantage of this method is that pure solid can be recovered from impure solution. In addition, crystallized products have both an attractive appearance and a convenient shape for packing, transport and storage. In the food industry crystallization of fats in margarine and chocolate, or sugar in sweets is widely used. It is also important in obtaining pure fresh water from sea water and in freezing as method of food preservation.
EXERCISES
1. Form the nouns from the given verbs using proper suffixes:
to act, to convert, to improve, to differ, to spoil, to achieve, to dry, to treat, to concentrate, to appear, to crystallize.
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2. How the prefixes PRE -, and COUNTER - change the meaning of the following words?
pretreatment, preheat, predetermine, precool, prefreezing, counterflow, countercurrent.
3. Translate into English:
концентрированный раствор, кристаллы льда, смесь растворителя и растворенного вещества, выжимание фруктов, сухое молоко, испарение жидкости, транспортные расходы, концентрация сахара, кристаллизация жиров.
4. Remember how NAPC is translated into Russian.
1. Separation of heterogeneous mixtures of two liquids is a common operation, the two liquids being of different densities. 2. All the advantages of the methods available having been considered, the best method was chosen. 3. The amount of sugar being insufficient, more sugar can be added.
4.A solution containing several crystallizable substances, more than one substance may crystallize out at the same time. 5. The most important properties that determine the quality of crystals are purity, the dimensions, shape and uniformity of size, the former being the most important.
5.Pay attention to the proper translation of sentences with SUBORDINATE CLAUSES.
1. Freeze drying is applied to valuable products which deteriorate too much in quality when dried by other methods. 2. It is questionable whether it is possible to find good quality water. 3. It was mentioned that an increase in the concentration of sugar has a preserving action. 4. The great advantage of this method is that pure solid can be recovered from impure solution. 5. That concentration is applied to water-rich liquid products is a well known fact. 6. Freeze-dried products are easily reconstituted provided water is added.
II. Skim Text 15B and try to understand what is about and what information is known to you.
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Text 15B
THE PREPARATION OF POWDERED MILK
The process of making powdered milk is an interesting operation. Milk comes from dairy farms scattered across the countryside. Each morning, large tank trucks stop at each dairy farm and collect the milk that has accumulated over the past day. Then it is transported to the creamery.
Once it gets here to the creamery, it's run through a filter and put into a holding tank. As it waits it's turn to go through the first stage of processing, it's run through a battery of tests to insure it meets quality standards.
Milk first passes into the evaporator where about a third of it's water is removed. During the evaporation process the milk is pasteurized. The pasteurization process reduces the bacteria content without heating the milk to the point that it is damaged.
Separating the Milk: From evaporator the milk runs through the separator which removes the cream or butterfat. The butterfat is placed in a separate storage tank to be used later. The skim milk now moves to the tanks where standardizing takes place.
Standardizing the Milk: After the milk has been separated, it is then standardized which means the different components of the milk are mixed automatically until we have a consistent product. During the standardization process, even some of the vitamins in the milk are checked to insure they meet our standards. This way the customer is assured of a wholesome, healthy product that never changes.
The remaining evaporated, condensed milk is turned into powdered milk. Depending on our customer's needs, we standardize this milk with butterfat levels ranging from less than 1% all the way up to 30% fat. After the condensed milk has been standardized, it's next stop is the drying tower.
Turning The Condensed Milk Into Milk Powder: Two types of drying are the spray nozzle and the newer atomization system. There are still many spray dryers in operation today. The operators can carefully control the moisture level of the finished product by controlling the swirling air in the tower. At this point any additives the customer wants are added to the agitating milk powder. Common additives are vitamins, minerals, lecithin or lactose as well as other compounds. The continual stirring action of the fluid bed finely mixes these additives into the milk powder. At this stage, we have regular, dehydrated milk powder.
Turning Regular Powdered Milk Into Instant Powered Milk: It's also in the drying tower where regular milk is turned into instant milk. This can be done 'on the fly.' First, not more than 0.2% lecithin is sprayed on the finer,
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dry milk particles that have been sifted out of the rest of the milk. The lecithin makes the powdered milk dissolve better. It's then moved back to the top of the drying tower and fed into the top of the tower near the spot where the atomizer is breaking up the condensed milk into microscopic droplets. As the dry and wet particles are mixed together, the wet particles stick to the dry particles and at the same time form air pockets. This larger particle dries as it falls down through the swirling air. This process gives you a much lighter product that is much more easily penetrated by water. Nutritionally, there's very little difference between instant and regular powdered milk. It's virtually the same product except the instant milk powder is less dense and mixes more easily in water. Although Lecithin is a very healthy food, there hasn't been enough added to the instant milk to show any differences in the nutritional data tables between the two. Concerning flavor, you shouldn't be able to tell the difference between them, either.
The last step in the process is to package it and send it to the customer. We send powdered milk in plastic lined 50 lb bags. Then they repackage it for long term storage.
EXERCISES
1. Identify the topic of each paragraph of Text 15B.
3. Give a brief overview of the structure and contents of Text 15B. using the following expressions.
The aim of the text is...
The text is devoted to ...
The text can be divided into … parts
The first part is about…
The second part deals with…
The third part describes…
According to the text…
To sum it up...
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Bibliography
1. Нестерова Н.Б. Английский язык. Food manufacturing processes:
Учеб.пособие. - СПб.: НИУ ИТМО; ИХиБТ, 2013. - 90 с.
2. Английский язык. Food manufacturing processes: Пособие / Сост.
Л.А. Васильева, Н.Б.Нестерова. 2-е изд., испр. и доп. - СПб.:
СПбГУНиПТ, 2004. - 154 с.
3.Foods and food production encyclopedia. Ed. by Douglas M. Concidine. - New York.: Van Nostrand Reinhold, 1982.
4.Food factories: Processes, equipment, costs. Ed. By Alfred Bartholomai. - Weinhein: VCH, 1987.
5.Saravacos, George D. Handbook of food processing equipment. - New York.: Klumer acad./Plenum, 2002.
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Содержание
Unit1 …………………………………………….………………………....4 Text 1A Mechanical operations in food industry. Text 1B Why do we eat? Unit 2……………………………………………….……………………....9 Text 2A Handling of the materials. Text 2B Food processing without human touch.
Unit 3………………………………………………………………………15 Text 3A Mixing of materials. Text 3B Food additives.
Unit 4…...……………………………………………………………….....20 Text 4A Mechanical mixing operations. Text 4B Technology of breadmaking.
Unit 5……………………………………………………………………....25 Text 5A Size reduction. Text 5B Manufacture of cocoa.
Unit 6………………………………………………………………………30 Text 6A Milling operations. Text 6B Milling of the cereals.
Unit 7……………………………………………………………………...34 Text 7A Size enlargement. Text 7B Process in confectionery production. Unit 8…………………………………………………………………..…..39 Text 8A Mechanical separation. Text 8B Sugar in confectionery production.
Unit 9…………………………………………………………………..…..44 Text 9A Separation of solids. Text 9B Cereals and cereal products.
Unit 10…………………………………………..…………………...….…49 Text 10A Classification of solid particles. Text 10B Curd.
Unit 11……………………………………………………………………..54 Text 11A Sedimentation. Text 11B Fruits processing plants.
Unit12…………………………………………………………………..…59 Text 12A Filtration. Text 12B Filtration equipment.
Unit 13…………………………………………………………………..…64 Text 13A Drying. Text 13B Dryers. Unit14……………………………………………………………………..69 Text 14A Freeze drying. Text 14B Preservation of foods.
Unit 15……………………………………………………………………..73 Text 15A Concentration and crystallization. Text 15B The preparation of powdered milk. Bibliography…………………………………….,………………………...78
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Учебное издание
АНГЛИЙСКИЙ ЯЗЫК
Учебное пособие для студентов направления подготовки бакалавров 151000
«Технологические машины и оборудование» (профиль «Машины и аппараты пищевых производств»)
Автор: Никитина Маргарита Юрьевна
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