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VI Give definitions to the words and find their derivatives from the text:

spoil; develop; concentrate; salt; preserve; popular; grow; help; pasteurize; discover; ferment; sterilize; perish; act; apply; long; favor

VII Speak on the topic using the following words and word-combinations:

the principal spoilage agents, to be present in food, to destro, to prevent development, to become the chief problem of food preservation;

methods commonly used, to include, refrigeration, canning, freezing, the use of preservatives, drying, storage under suitable conditions;

food, to be preserved, the application of high temperatures;

to be pasteurized at a temperature of, for thirty to forty minutes, during, most of the organisms, to be killed.

VIII Write down a paragraph which tells about chemical agents used for foodstuff preservation.

IX Read and remember:

1.ultraviolet light –ультрафиолетовый свет

2.spoilage organisms –организмами, вызывающими порчу

3.smooth surfaces –гладкие поверхности

4.germ-free -зародыш

5.radiation –радиация

6.radioactive materials –радиоактивные материалы

7.to sterilize foods – стерилизовать пищевые продукты

8.odd tastes and smells –странные вкусы и запахи

9.irradiation –облучение

10.sprouting of stored vegetables –прорастания, хранящихся овощей

11.availability –доступность

12.consumer – потребитель

13.to be pump out –откачивать

14.vacuum chamber –ваккумная камера

X Read the text and define the main idea of it:

TEXT B

New methods of food preservation

Ultraviolet Light. Ultraviolet light, which is part of the light coming from the sun, will kill spoilage organisms. Since the amount of ultraviolet light that the sun gives off is not enough to kill the organisms quickly, scientists have made special lamps that give off ultraviolet light. The light from these lamps can kill spoilage organisms on smooth surfaces or on foods that can be spread out in a thin layer. But since the light cannot go deeply into the food, food that either is thick or has an uneven surface cannot be made germ-free.

Radiation. The radiation from radioactive materials has been used to sterilize foods. This method is not completely successful because it causes odd tastes and smells. But it has been demonstrated that irradiation can prevent sprouting of stored potatoes and other vegetables. This prolongs their storage quality and availability to the consumer.

Freeze-Drying. This is a new and still expensive process. Fresh food is quickly frozen and placed in a chamber from which all the air is removed, creating a vacuum. Because of the vacuum, the frozen moisture in the food turns into water vapor without melting. The water vapor is pumped out of the vacuum chamber as fast as it forms, leaving the food with very little moisture. A piece of fruit treated by this process looks very much like fresh fruit, but it is very dry and porous (has tiny holes that will let in water). When ready for the table, freeze-dried foods look like fresh foods.