Pollution Prevention and Control

Good pollution prevention practices in the dairy industry include:

• Reduction of product losses by better produc­tion control.

• Use of disposable packaging (or bulk dispens­ing of milk) instead of bottles where feasible.

• Collection of waste product for use in lower-grade products such as animal feed where this is feasible without exceeding cattle feed qual­ity limits.

• Optimization of use of water and cleaning chemicals; recirculation of cooling waters.

• Segregation of effluents from sanitary instal­lations, processing, and cooling (including con­densation) systems; this facilitates recycling of wastewater.

• Use of condensates instead of fresh water for cleaning.

• Recovery of energy by using heat exchangers for cooling and condensing.

• Use of high-pressure nozzles to minimize wa­ter usage.

• Avoidance of the use of phosphorus-based cleaning agents.

Continuous sampling and measuring of key production parameters allow production losses to be identified and reduced, thus reducing the waste load.

Odour problems can usually be prevented with good hygiene and storage practices. Chlorinated fluorocarbons should not be used in the refrig­eration system.

Exercise 2. Find the explanations of the following in the text. Fill in the table using the information from the text:

BOD
COD
wastewater
total dissolved solids

Exercise 3. Answer the questions to the text.

1. What does the dairy industry involve?

2. What are the typical by-products in the dairy industry?

3. What do dairy effluents contain?

4. What are the key parameters of BOD?

5. What may the wastewater contain?

6. What also can be generated during manufacture?

7. What do good pollution prevention practices include?

8. How can odour problems be prevented?

9. What allows to reduce the waste load?

10. Do you consider the information given in this text to be important? Why?

Exercise 4. Write down the classification of wastes produced during raw milk processing. Compare it with classifications made by your group mates.

Exercise 5. Speak about the measures which should be done to prevent pollution during dairy products manufacture.

UNIT 4. CARBOHYDRATES

Exercise 1. Read and memorize the words.

perform, v	исполнять, выполнять
starch, n	крахмал
cause, v	вызывать, являться причиной
wheat, n	пшеница
sorghum, n	сорго (хлебный злак)
millet, n	просо
maize, n	кукуруза
rye, n	рожь
tuber, n	клубень
legume, n	плод бобовых, боб; стручковое растение
refine, v	очищать
carbon dioxide	углекислота, углекислый газ
release, v	освобождать
inhibit, v	задерживать, подавлять

Exercise 2. Read and translate the text. Carbohydrates

From carbohydrates we get most of the energy which we need to act and move, perform work, live. Among the carbohydrates are sugars, starches, and celluloses. All green plants form carbohydrates. Carbohydrates are important in nutrition for many reasons. Some of them make our food sweet. Some of them cling to our teeth and serve as food for bacteria that cause tooth decay.

The body needs carbohydrates in order to use fat efficiently. Some diseases, such as diabetes, develop because the body is unable to use carbohydrates properly. The carbohydrates contain carbon, hydrogen and oxygen. The hydrogen and oxygen usually occur in the same proportion as in water.

Most of the different kinds of carbohydrates are plant products. Plants made them by photosynthesis, a complex chemical process that consists of a series of reactions at least one of which may occur only with the aid of sunlight and the green plant pigment, chlorophyll. Many different kinds of carbohydrates occur in foods. Not all are of equal importance in nutrition. Starch, which consists of glucose units, is the only polysaccharide that man can use efficiently. Nutritionally it is far and away the most important carbohydrate.

Cereal grains, our most important source of carbohydrate are rich in starch; rice, wheat, sorghum, corn maize, millet and rye contain about 70 per cent of starch. Potatoes and other tubers and roots are also rich in starch. Beans and seeds of many other legumes are high in protein, but 40 per cent or more of their dry matter is starch. Only two of the disaccharides (these contain two monosaccharide units) are of much importance nutritionally. One is sucrose-cane sugar or beet sugar, which is available as a highly refined and relatively pure carbohydrate. The other important disaccharide is lactose, or milk sugar, which makes up almost 40 per cent of the solids in fresh whole milk. It is the only carbohydrate of animal origin that is of significance in nutrition. It is made up of one glucose unit and one galactose unit. Galactose is a hexose and differs only slightly in chemical structure from glucose.

The monosaccharides are important in nutrition mainly because they are the units of the more complex carbohydrates. A few of them do occur and are eaten in the free form. Glucose and fructose, a hexose quite closely related structurally to glucose, are in honey and fruits. Relatively few of the other carbo­hydrates occur widely enough or are utilized well enough by the body to have much nutritional importance. The energy from carbohydrates becomes available to the body when glu­cose is broken down in the tissues.

Complete breakdown involves oxidation and yields carbon dioxide and water. The oxidative processes which release energy for our activity involve many enzymes and coenzyimes.

The enzymes must be synthesized from amino acids, the units of which the proteins in our diet are composed. The coenzymes contain vitamins and often minerals that also are essential nutrients. A lack of any of them can depress or inhibit important steps in the body's utilization of carbohydrates.

Besides providing energy carbohydrates affect food consumption indirectly through their flavour, through their influence on the amount of water into the stomach.

 A few of them do occur and are eaten in the free form. – Немногие из них встречаются и используются в свободном состоянии.