Молекулярная гастрономия для креативных шеф-поваров (англ. язык) - страница 138

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


Cooking vegetables

Raw vegetables, unlike meat, can be eaten raw. However vegetables are generally cooked to soften

their texture and thus improve their digestibility, as well as intensify their flavour (compare the taste of

raw and steamed broccoli!).

However cooking also has some less desirable consequences – such as loss of their natural colour

and reduction in nutrient value.

Flavour changes on cooking

High temperatures make the aromatic molecules contributing to the flavour more volatile and therefore

more easily detected. However overcooking will cause these volatile molecules to be evaporated or

destroyed, so vegetable soups that have been cooked for a long time often need to be generously

seasoned at the end of cooking to make up for the loss of flavours. The odour of vegetables also

develops as a vegetable is cooked – this is also because the volatile odour molecules become more

volatile and easier to detect. Equally heating can result in odourless smell molecules being

transformed into highly aromatic molecules. Cabbages and leeks are especially common for their

potent smell released on cooking.

Texture changes on cooking

Some vegetables, especially those that are tubers or storage parts of the original plant, contain large

amounts of starch, and cooking, like for rice and pasta, therefore is essential to gelatinize their starch

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and improve digestibility. Vegetables of this type include the potato family and have been considered

in another section.

Other vegetables have a particularly tough cell wall and these vegetable are often preferentially

cooked because cooking causes their cell walls to weaken, improving digestibility of the vegetable.

These vegetables include carrots and beetroot. Equally, vegetables with a softer cell wall, such as

lettuce, should not be cooked at all – raw, their digestibility is fine.

Plant cell walls are made up of complex carbohydrate molecules - cellulose, pectin, and

hemicelluloses. Each of these molecules is affected differentially by heat. Because the cell walls of

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