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Б). Подберите к словам в левой колонке слова с противоположным значением из правой колонки.
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| 1) major 2) thin | a) minor a) small | b) long b) thick | c) delicate c) deep |
| 3) increase 4) presence | a) call a) transfer | b) decrease b) rate | c) exclude c) absence |
| 5) to retain 6) freezing | a) to lose a) chilling | b) to handle b) cooking | c) to store c) thawing |
| 7) slowly 8) heat 9) cold (adj) 10) liquid | a) widely a) smoke a) hot a) vapor | b) rapidly b) cold b) dry b) air | c) quickly c) thing c) wet c)solid |
11. Подберите к следующим терминам их определения:
| 1) preserve | 1. Water or other liquid dispersed in very small drops. |
| 2) shelf life | 2. To make a mechanism function. |
| 3) to operate | 3. To make extremely cold in order to preserve and store food. |
| 4) refrigeration | 4. A way of freezing which uses cold air moving rapidly in rooms or tunnels. |
| 5) humidity | 5. The time for which a stored thing remains usable. |
| 6) agent | 6. A cupboard with drawers or shelves for storing or displaying articles. |
| 7) blast freezing | 7. An element, compound or substance which can produce a chemical or physical effect. |
| 8) spray | 8. A container for preserving and storing perishable goods by freezing them and keeping them at a very low temperature. |
| 9) cabinet | 9. dampness (moisture content) of the air. |
| 10) freezer | 10. To keep from decay, to treat (food, e.g. fruit or meat) so that it can be kept for future use. |
Найдите в тексте А предложения, содержащие герундий.
Переведите их на русский язык с учётом функции герундия.
Укажите, какие предложения соответствуют содержанию
текста А. Подтвердите свои ответы фактами из текста.
1. The term «refrigeration» applies to temperatures between 2 and 5ºC.
2. Refrigeration usually begins with the chilling of carcasses shortly after slaughter.
3. The refrigerated storage of meat products is limited to relatively short periods of time.
4. Freezing results in more undesirable changes in organoleptic properties of meat than the other methods of preservation.
5. The heat transfer medium in plate freezers is air.
6. Liquid immersion or spray is used only for freezing poultry.
7. The most commonly used cryogenic agents are nitrogen and carbon dioxide.
14. Закончите предложения в соответствии с содержанием
Текста А.
1. The most common method of prolonging the shelf life of meat is the use of …
a) high temperatures
b) refrigeration
c) home freezer units
2. The type of product being stored is one of the major factors that influence …
a) the storage life of meat
b) humidity conditions during storage
c) rapid air movement in freezing tunnels
3. In cryogenic freezing the heat transfer medium is …
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a) air
b) metal
c) nitrogen or carbon dioxide
15. Ответьте на вопросы к тексту А.
1. What is preservation?
2. How is the term «refrigeration» defined?
3. Is only fresh meat stored under refrigeration?
4. Why is freezing recognized as an excellent method for preserving meat?
5. Most of the nutritive value of meat is retained during freezing isn’t it?
6. What are the common methods for freezing meat products?
7. Is liquid immersion method used for freezing poultry or fish?
Составьте таблицу, указав в ней названия методов замораживания и название теплоносителя для каждого из них.
| Метод замораживания | Теплоноситель |
17. Составьте план пересказа текста А. Выпишите ключевые слова к каждому пункту плана. Перескажите текст, пользуясь планoм к ключевыми словами.
18. Прочитайте заголовок текста В и переведите его на русский язык. Просмотрите текст, обращая внимание на выделенные слова. Это поможет Вам ответить на вопросы:
А) На каких принципах основана термообработка?
Б) Какие два основных вида термообработки применяют для сохранения мясных изделий?
Text B
Thermal Processing
Heat processing, as a method of preservation, is used to kill spoilage and potentially toxic microorganisms in meat and meat products, and to inactivate endogenous enzymes that could cause deteriorative changes. This is in contrast to the refrigeration and freezing processes, which slow or stop microbial growth but generally do not kill microorganisms. Two general levels of heat processing are employed in meat preservation. A moderate heating process, where products reach temperatures of 58°-75°C, is employed in the cooking of most processed meat items. This heat treatment kills part, but not all, of the microorganisms present, and will inactivate other organisms. This process is referred to as pasteurization. The shelf life of meat products is extended by this pasteurization process, but they must still be stored under refrigeration after being processed. A more severe heating, generally to temperatures above 100°C, is used to prepare "commercially sterile" meat products that are stable at room temperature for one or more years. This process is called sterilization. This treatment either kills all potential spoilage organisms, or causes sufficient damage to microbial cells so that growth is impossible. The palatability of meat generally decreases as it is heated to temperatures above those used for pasteurization.
Heat transfer. All conventional methods of thermal processing involve heat transfer by conduction, convection, and/or radiation. Heating by conduction involves the direct transfer of heat from particle to particle without the use of a medium other than the product itself. For example, the transfer of heat from the surface to the center of a solid piece of meat is almost entirely by conduction. Convection heating involves heat transfer by the mass movement of heated particles in a "fluid" such as air, steam, or water. Heating by radiation is the transfer of heat energy through space. One or more of these heat transfer mechanisms are involved in all of the procedures used to thermally process meat products.
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It is important to consider the factors that affect the rate and extent of heating, as well as fundamental heating principles, when specific thermal processing schedules are developed for a meat product. However, meat products vary widely in amounts of fat, water content, consistency, and homogeneity, so that a calculation of exact processing schedules is virtually impossible. Thermal processing schedules usually must be developed on an individual product basis, and sometimes even on an individual plant basis, due to variations in specific equipment.
Heat resistance of microorganisms. Cells and spores of microorganisms differ widely in their resistance to high temperatures. Some of these differences are the result of factors that can be controlled, and others are due to characteristics of the organism that cannot be controlled. Factors that are known to affect the heat resistance of cells and spores must be considered when thermal processes for the destruction of microorganisms are developed for, or applied to, the production of meat products.
Methods of thermal processing. The commercial heat processing of canned products (such as canned hams and luncheon meat) to pasteurization temperatures is generally done by immersing the sealed cans in water that is heated in open kettles or vats. The water temperature is usually less than 100°C under these conditions, but higher temperatures can be reached by adding salts, such as calcium or sodium chlorides, to increase the boiling point. Heating in open kettles is not recommended for the production of commercially sterile products because of the extremely long processing times required, and the danger of inadequate heat treatment in these meat products.
Thermal processing to achieve sterility is usually done in large metal drums, known as retorts, which are capable of withstanding pressures of up to 32 kg/cm2. The sealed cans are placed in the retort, which is then closed, sealed, and heated. Heat is applied by heating water under pressure, or by injecting superheated steam, or a mixture of steam and air. Temperatures of 120°C or higher are routinely achieved in the retort, which greatly reduces processing time over the open kettle method. In addition, the cans are often agitated, in order to further shorten the processing time.
УПРАЖНЕНИЯ
19. Найдите в тексте В ответы на следующие вопросы:
1. Does heat processing as a method of preservation kill spoilage and toxic microorganisms in meat?
2. What method of preservation merely slow or stop microbial growth?
3. Which process is a severe heating, pasteurization or sterilization?
4. What is the main difference between sterilizing and pasteurizing processes?
5. What principles are all conventional methods of thermal processing based upon?
6. How is generally pasteurization of canned meats done?
7. When are large metal drums, known as retorts, used?
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