6. Ответьте на вопросы:

1. What is the subject of the text? 2. What causes food spoilage? 3. What methods of food preservation are spoken about? 4. What are the principles of food heating? 5. Why has canning become popular in food preservation? 6. What foods can be preserved by refrigeration? 7. What changes can foods under cold storage undergo? 8. How are foods affected served by freezing? 9. What chemical preservatives are usually used for food preservation? 10. What is the main requirement for efficient drying of foods? 11. What alteration of the product does drying cause? 12. What happens to the freeze-dried product? 13. Why does the sublimated product require no refrigeration? 14. How is the reconstruction of foods achieved? 15. What are the advantages of freeze drying?

7. Кратко расскажите на английском языке:

1. о средствах сохранения пищи и их главной цели;

2. о принципах тепловой обработки;

3. о возможности сохранения скоропортящихся продуктов методом консервирования;

4. о хранении продуктов методом охлаждения;

5. об основных консервантах пищи;

6. о пользе сушки пищевых продуктов;

7. о восстановлении сублимированного продукта;

8. о преимуществах сублимационной сушки.

8. Кратко перескажите текст на английском языке и выскажите свое мнение по обсуждаемой теме.

9. Прочитайте текст В₄ без словаря и составьте план на английском языке.

10. Подтвердите, что:

а) сушка и соление продуктов использовались еще в древности;

б) производство продуктов рассматривалось в прошлом как часть химической технологии.

11. Расскажите о развитии технологии пищевых производств.

Text B₄ FROM THE HISTORY OF FOOD PROCESSING AND

PRESERVATION

Notes

1. trade guild – зд. ремесло

2. to cure – мариновать, засаливать

3. fowl – домашняя птица

4. batch – цикл, циклический

The food industry has its roots in the remote past. Almost every subdivision of the food industry and particularly those dealing with grain and bread, meat and meat products, fish and fish products, spices and preserved foods, was a well-defined trade guild¹. From the experience of generations, food technology developed just as other sciences developed. Milling and baking were well developed in ancient times. There were both private and public ovens of baking bread. From the point of view of preservation of foods, some practices are immemorial. Thus, freezing or icing of meat was used in all parts of the world where ice was obtainable and where cold weather prevailed at some time during the year. Curing²meat by the addition of salt is another ancient method. The drying and salting of fish as performed by the Egyptians are shown in their sculptures and there are Egyptian paintings illustrating the catching, keeping, feeding, killing, salting, cooking, and eating of fowl³. The Romans also preserved fish with salt. Cheese was manufactured thousands of years ago. Butter is also an ancient food.

It is clear, however, that in all these instances the product was prepared or preserved not on a large commercial scale. The production of food, as an industry, actually has a history extending as far as the history of modern chemistry because it was considered a part of chemical technology. Thus, Chemical Technology published in 1870 contained the following sections: starch, sugar manufacture, cane sugar, beet sugar, fermentation, wine making, beer brewing, spirits, bread baking, manufacture of vinegar, and essential oils.

Food technology developed in full with the growth of the processing industries and with improvement in food machines, transportation, refrigeration, storage and packaging. The canning of foods was made practical about 1809. The tin can was first introduced about 1810 but it was not until about 1870-1875 that canning really developed as an industry.

At the start of even modern food processing, most operations were batch⁴processes, but with the development of adequate food machines and instruments for automatic control, many manufacturing steps were first made partially continuous and finally fully automatic and continuous.

Письменно переведите текст С₄ на русский язык.

Text C₄ MAJOR CAUSES OF FOOD DETERIORATION

The major causes of food deterioration include the following: (1) growth and activities of microorganisms, principally bacteria, yeasts, and molds; (2) activities of the natural food enzymes, (3) insects, parasites, and rodents; (4) temperature, both heat and cold; (5) moisture and dryness; (6) air, and more particularly oxygen; (7) light; and (8) time.

These factors are not isolated in nature. Bacteria, insects, and light, for example, can all be operating simultaneously to deteriorate food in the field or in a warehouse. Similarly, such factors as heat, moisture, and air will all affect the multiplication and activities of bacteria, as well as the chemical activities of the natural food enzymes.

At any time, many forms of deterioration may take place, depending upon the food and environmental conditions. Total food preservation must eliminate or minimize all of these factors in a given food. Thus, for example, in the case of canned meats we sterilize the canned product to kill microorganisms and to destroy natural meat enzymes. We put the meat in a metal can which protects it from insects and rodents, as well as from light which could deteriorate its color and possibly its nutritive value. The can also protects the meat from drying out. Vacuum is applied, or the can is flushed with nitrogen to remove oxygen. The cans are stored in a cool room and the length of time the cans are held in supermarkets and in our homes is limited. In this case the preservative method takes into account all of the major factors in food deterioration. It is well to consider these factors individually.