A) Прочтите текст и озаглавьте его.

B) Скажите, каким образом данный текст связан с предыдущим.

C) Какие новые сведения вы узнали из данного текста?

d) Скажите, какое из следующих утверждений не соответствует тексту:

1) Odd fatty acids are rather intensively metabolized.

2) Attention to the utilizing of hydrocarbons as the raw material for the yeast growing is increasing.

3) Yeasts grown on some oxy-hydrocarbon derivatives meet the requirements of food quality.

4) The prices of one and the same raw material are different in different countries.

e) Ответьте на следующие вопросы:

1. What does oxidation of n-alkane molecule by yeasts lead to?

2. When do yeast synthesize the mixture of odd and even fatty acids?

3. What is well known about odd fatty acids?

4. Are they intensively metabolized?

5. What has not been established by the very careful experiments on animals?

6. What recommendations have been devised?

7. What do they guarantee?

8. What is a tendency of the research work in the field of the single cell protein production in the last few years?

9. What did investigation carried out discover?

10. The lipid composition of the yeasts grown on the methyl alcohol is similar to that of the yeasts grown on glucose, isn’t it?

11. What substrate is better for the yeast growing?

12. What products of hydrocarbon oxidation are of great economic utility in the food yeast production?

f) Определите количество смысловых кусков, озаглавьте каждый из них. Передайте содержание каждого смыслового куска на английском языке.

TEXT 18.

One of the essential conditions for the success of artificial food products is that they should have a pleasant flavour. The possibility of imitating the flavour and the taste of food products based on sound scientific foundation has appeared only recently. It is based on the development of precise methods of gas-liquid chromotographic analysis of complex mixtures of compounds as well as on the advances in the physical chemistry of polymers.

The taste of the food is dependent, on the one hand, on its physical structure, the physico-chemical properties of the structure, and, on the other hand, on the chemical interaction with the taste receptors of the mouth. The latter can be imitated, for most natural products, by combining the four principal tastes such as sourness, saltness, bitterness and sweetness. The use of taste intensifiers such as salts of glutaminic, 5-inosinic, and 5-guanilic acids and a number of other compounds results in a substantial amelioration of the gustatory properties of the products and intensifies the taste specific to the particular kind of products.

It is much more difficult to imitate the flavour of food products due to the absence of a suitable theory that would enable correlation of the physico-chemical properties and the flavour of a particular compound and, especially, of mixtures. In order to obtain an aromatic composition for food products it is, therefore, necessary to decipher the flavours of natural products that are often acomposition of a great number of compounds (sometimes exceeding 200) with their concentration being as low as several weight fractions in a million.

The flavour imitator must be obtained for every particular artificial product with a definite texture of food polymers, bearing in mind the change in texture affects the adsorption of individual volatile components participating in the flavour and thus the flavour of the artificial product. Our results with artificial protein caviar exemplify the possibility of fairly exact imitation of the flavour of a food product.

To this end a special method of non-standard gas-chromatography for the analysis of the flavour components was developed.

It has been found that the specificity of caviar flavour is dependent primarily on amine compounds, with the difference in various types of caviar being due to the relative amount of amines in particularly similar qualitative composition. These findings were used to obtain an imitator of the flavour of the artificial protein caviar.

It turned out that to imitate the flavour it is not at all necessary to reproduce exactly the whole complicated composition of the flavour of the natural product. It suffices to find the flavour-determining components. Thus for example, it proved possible to prepare theimitator of the flavour for artificial caviar on the basis of four compounds only.

Notes on the text:

1) amelioration – улучшение

2) gustatory – вкусовой

3) flavour – запах, вкус, привкус

4) to decipher – расшифровывать

5) to this end – с этой целью

6) caviar – икра

Задания к тексту:

A) Прочтите текст, придумайте заголовок, отражающий тему.

b) В 1 абзаце текста найдите предложения со словосочетанием sound scientific foundationи догадайтесь по контексту о значении слова sound. Переведите данное предложение на русский язык.

C) Во 2 абзаце текста найдите предложение, в котором говорится о четырех основных вкусовых ощущениях. Переведите данное предложение на русский язык.