Упражнения.

1. Найдите в тексте 4А эквиваленты следующих слов и выражений: технологический процесс, разливочная машина, содержание жира, резервуар, установить что-либо нужного уровня, сохранять постоянным, потреблять меньше энергии, устройство, остаток (излишек), увеличивать давление, утечка, температурный датчик, необработанное молоко, расходомер, индикатор плотности, распределительный клапан.

2. Найдите в правой колонке эквиваленты английских слов, to pump устанавливать

to increase нагревать

to occur обеспечивать

to require перекачивать

to heat поддерживать

to provide загрязнять, портить

to contaminate потреблять

to consume охлаждать

to set увеличивать

to maintain случаться, происходить

3. Придумайте вопросы к данным ответам.

1. The purpose of standardisation is to give the milk a defined, guarantied content.

2. They are liquid products made from milk, used directly by consumers.

3. A correct cooling, pasteurisation is one of the important processes in the treatment of milk.

4. The pasteurisation process may vary from one country to another according to national legislation.

5. A common requirement in all countries is that the heat treatment must guarantee the destruction of unwanted microorganisms without the product being damaged.

6. The purpose of homogenisation is to disintegrate the fat globules in the milk in order to reduce creaming.

7. Homogenisation may be total or partial.

8. Partial homogenisation is more economical, because a smaller homogeniser can be used.

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4. Переведите на английский язык.

1. Температура и время пастеризации - очень важные факторы, которые должны быть определены точно в соответствии с качеством поступающего молока и требованиями по сроку годности.

2. Молоко поступает в резервуар и перекачивается в тарельчатый теплообменник, где предварительно разогревается.

3. Из тарельчатого теплообменника нагретое молоко попадает в сепаратор, где получаются сливки.

4. Содержание жира в сливках устанавливается на требуемом уровне.

5. Уровень жира поддерживается постоянным контролирующей системой.

6. Эта система потребляет меньше энергии.

7. Пропускная способность гомогенизатора тщательно фиксируется на определенном уровне.

8. Бустерный насос увеличивает давление до уровня, при котором пастеризованный продукт не может быть испорчен не обработанным молоком, если случается утечка в тарельчатом теплообменнике.

9. Температурный датчик сигнализирует, если температура падает. 10. После пастеризации молоко попадает в охлаждающий отсек

теплообменника, где охлаждается поступающим не обработанным молоком.

5. Составьте предложения со словами, данными перед текстом.

6. Разделите текст на смысловые части, озаглавьте каждую из них.

7. Перескажите текст 4А.

8. Прочитайте текст 4В.

Text 4B.

Shelf Life of Pasteurised Milk.

The shelf life of pasteurised milk is basically and always dependent on the quality of the raw milk. Naturally it is also important that production conditions are technically and hygienically optimised, and that the plant is properly managed.

When produced from raw milk of high quality and under good technical and hygienic conditions, ordinary pasteurised milk should have a shelf life of 8-10 days at 5-7" С in an unopened package.

The shelf life can however be drastically shortened if the raw milk is contaminated with microorganisms.

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To improve bacteriological status of pasteurised milk and thereby safeguard or even prolong its shelf life, the pasteurisation plant can be supplemented with bactofugation or microfiltration plant.

The bactofugation process is based on sentrifugal separation of microorganisms.

Good effect on bacteria and spores can be achieved with microfilter membranes of pore size. In addition to microfilter module the plant contains a high temperature treatment unit for the mixture of the cream phase and bacteria concentrate. Then the product is sterilised at about 130" С for a couple of seconds, homogenised and finally paseurised at 72" С for 15 - 20 seconds. Then it is cooled to +4"C.

Some plants can handle up to 10 000 liters of raw milk per hour. After separation, the skimmilk is routed to microfilter module. Part of the cream, typically 40 % fat content, is remixed with the skimmilk to produce fat-standardised pasteurised market milk while the surplus cream is separately processed. The proportions of remixed and surplus cream depend on the specified fat content of the market milk.

Milk treated in this way will keep its fresh flavour and white colour. Moreover, if strictly hygienic conditions are maintained in the plant, from reception of the raw milk up to and including the packaging and filing system, the foundation of a long shelf life is laid. If the milk is kept at a temperature not more than + 7" С during the whole chain from the dairy to consumer, it is possible to attain a shelf life of up to 40 - 45 days in an unopened package.

9. Ответьте на вопросы к тексту 4В.

1 What does the shelf life of pasteurised milk basically depend on?

2. What does the process of bactofugation improve?

3. What does the bactonidation process based on?

4. What effect can be achieved with microfilter membranes?

5. What temperature should be the milk kept at?

10. Выразите основную мысль текста тремя предложениями.

Unit 5.

Выучите слова и выражения

Silo -бункер

Whey powder - сухая сыворотка

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Bulk - сыпучий

Anhydrous milk fat (AMF) - обезвоженный молочный жир

Oxidation - окисление

Batch -порция

Ageing -выдерживание, созревание

Ageing tank - чан для созревания

Mixing tank - смеситель

Compressed air - сжатый воздух

Condensed milk - сгущенное молоко

То whip - взбивать

Ammonia jacket - охлаждающая рубашка из аммония

Mutator - мутатор

Extrusion - экструдирование

Moulding - формование

Ripple - волнистый

Feeder unit - подающий механизм

То lid - запечатывать

Rotary filling machine - ротационная машина для наполнения

Text 5

A Ice cream

It is uncertain how long ice cream has been produced, but it probably originates from China. From very old writings it has been learned that the Chinese liked a frozen product made by mixing fruit juices with snow, what we now call water ice. This technique later spread to ancient Greece and Rome, where the wealthy, in particular, were partial to frozen desserts .

After disappearing for several centuries, ice creams in various forms reappeared in Italy in Middle Ages, most probably as a result of Marco Polo returning to Italy in 1295 after a 16-17 year stay in China, where he had learned to appreciate a frozen dessert based on milk. From Italy ice cream spread over Europe during the seventeenth century, and long remained an luxury product for the royal courts.

Sales of ice cream to the general public in the United States started in the eighteenth century, but did not become widespread until the nineteenth century, when the first wholesale company appeared on the market.

Ice cream can be divided into main categories according to the ingredients used:

Ice cream made exclusively from milk products,

Ice cream containing vegetable fat,

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Ice cream made of fruit juice with added milk fat and milk solids-non-fat, Water ice made of water, sugar and fruit concentrate. The ice cream process consists of several steps.

Reception and storage of raw materials

Raw materials are stored in tanks, silos, drums or bags depending on their physical form. Arrangements for reception depend on the capacity of the plant.

Dry products used in comparatively small quantities, such as whey powder, stabilisers and emulsifiers, cocoa powder, etc., are usually delivered in bags. Sugar and milk powder can be delivered in containers and blown to storage silos by compressed air. Bulk materials such as sugar and milk powder may also be delivered in bags that are emptied by special machines.

Liquid products such as milk, cream, condensed milk, liquid glucose and vegetable fats are delivered by tankers. Milk products are chilled to about 5C before storage, while sweetened condensed milk, glucose and vegetable fat must be stored at are relatively high temperature to leave the viscosity low enough for pumping. Milk fat is delivered in the form of anhydrous milk fat (AMF), or in blocks of butter which are melted and pumped to storage tanks where a temperature of 35-40C must be maintained. In the latter case batches for one to two days' production are prepared to avoid oxidation of the milk fat, unless it is stored under an inert gas.

Formulation

The weight or volume of the individual ingredients must be carefully determined before they are mixed. To obtain a well - balanced mix it is essential to calculate the percentage of all ingredients. This process is called formulation.

Homogenisation and pasteurisation

In large-scale production the ice cream mix flows through a filter to a balance tank and is pumped from there to a plate heat exchanger where is preheated to 73 - 75 С

AMF or vegetable fat can be proportioned and blended into the flow in an in-line mixer en route to the hbmogeniser. After homogenisation at 14-20 MPa (140-200 bar), the mix is pasteurised.

In batch production the mix, including a metered quantity of fat, is first pasteurised in the combined mixing and processing tank, typically at 70C with a hold of 30 minutes. The mix is then passed through the homogeniser, cooled to 5 С in a plate heat exchanger and transferred to ageing tank.

In large-scale plants the homogenised mix is returned to the plate heat

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exchanger and pasteurised at 83-85C for about 15 seconds. The pasteurised mix in then cooled to 5С and transferred to an ageing tank.

Ageing

The mix must be aged for at least 4 hours at a temperature between 2 and 5С with continuous gentle agitation. Ageing allows time for the stabiliser to take effect and the fat to crystallise.

Continuous freezing

The continuos freezer has two functions:

• to whip a controlled amount of air into the mix;

• to freeze the water content in the mix to large number of small ice crystals.

The mix is pumped into a cylinder refrigerated by an ammonia jacket. The freezing process is very rapid; this is very important for the formation of small ice crystals. The layer of frozen mix on the cylinder wall is continuously scraped off by a rotating knife-equipped mutator inside the cylinder.

From the ageing tanks the mix is passed to the continuous freezer, where air is whipped in while it is frozen to between -3C and -6C depending on the ice cream product. Increase in the volume by the incorporation of air in ice cream mix is called "overrun" and is normally 80-100%, i.e. 0.8 to 1 liter of air per litre of mix . The ice cream leaving the continuos freezer has a texture similar to soft ice, and some 40% of the water content is frozen. It can therefore be pumped to the next stage in the process, which is either packing, extrusion or moulding.

Fruit ripple and dry ingredients like pieces of fruit, nuts or chocolate can be added to the ice cream immediately after the continuous freezer. This is done by connecting a ripple pump or an ingredient feeder unit to the ice cream line.

Packing , extrusion and moulding

Packing in cups , cones and containers

Ice cream is packed in cups, cones and containers ( 1 to 6 liters) in a rotary or in-filling machine. These can be filled with various flavours, and the products may be decorated with nuts, fruits and chocolate. The packs are lidded before leaving the machine, after which they are passed through a hardening tunnel where final freezing down to - 20C takes place. Before or after hardening

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the products can be manually or automatically packed in cartons or bundled.

Plastic tubs or cardboard cartons can be filled manually from a can equipped to supply single or twin flavours.