Молекулярная гастрономия для креативных шеф-поваров (англ. язык) - страница 23

Молекулярная гастрономия для креативных шеф-поваров (англ. язык)

Although enzymes are responsible for controlling reactions producing undesirable effects such as the

rancidity of foods and the browning of cut fruit and vegetables, they are also indispensable to cooking

processes such as the making of bread and beer.

Enzymes are proteins, so their structure is thus affected by heat and pH. Since their structure,

especially of their active sites, is essential to their functioning, understanding how pH and heat affect

enzyme controlled reactions can be very useful to the chef – both in order to prevent the unwanted

reactions, and increase the rate of those desired ones.

Pigments

Pigments are proteins involved in determining colour. Pigments will reflect only certain wavelengths of

visible light, and will absorb all other wavelengths. This affects the final colour. For example,

chlorophyll, the pigment found in green vegetables, absorbs all wavelengths of visible light except

green, which it reflects. This is why green vegetables appear green. Red meat pigments absorb all

wavelengths except for red, giving meat its red appearance.

The light absorbing properties of these pigments depends strongly on their structure. Even a very

small change in structure may completely affect the light wavelengths that can be absorbed and those

that are reflected. Since enzymes are proteins, and thus affected by changes in heat and pH, the

colour of many foods will change when subjected to these extreme conditions....

affected by changes in heat and pH, the

colour of many foods will change when subjected to these extreme conditions. Understanding these

changes can therefore be very useful in controlling the colour of vegetables and fruits, or even meat, in

the presence of pH or heat.

absorbed

reflected

IV/III - 1 (of 2)

What should be known about culinary ingredients: Fats

Fat structure

Fats are various molecules. One particularly important kind of fats are “triglycerides”.

Triglycerides contain a molecule of glycerol attached to three fatty acids molecules, as depicted

below:

H

H

H

C C

O

O

O

O

R1

R2

R3

H C O C

H C O C

Glycerol Fatty acids

The R groups represent long chains of carbon atoms attached together, and the three R groups can

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