xxxiii BELITZ H-D, GROSCH W, Food chemistry, chap 11 eggs ; 18.104.22.168 Proteins table 11.3 p405
xxxiv THIS H., Molecular Gastronomy, ascientific look on cooking, The 6X°C egg.
IV/I - 1 (of 2)
What should be known about culinary ingredients: Water
Pure water is filled with water molecules which are constantly moving around. Each of these water
molecules is composed of two hydrogen atoms and one oxygen atom, organised in a “V” shape as
Although this molecule is neutral, and is not charged overall, its charge is actually evenly distributed
throughout its structure – the oxygen (O) atom carries a weak negative charge, whereas each
hydrogen (H) carries a weak positive charge. This makes the water molecules attract one and other. In
water, which contains many of these molecules, the negative oxygen atom on some water molecules
will be attracted to the positive hydrogen atoms on other water molecules (in a similar way to the north
and south poles of magnets) and this attraction is called a hydrogen bond.
When water is heated, the molecules will start to move around with more energy and speed, so these
links will start to break, freeing the water molecules, and some of these water molecules will escape
(this is water vapour). At 100 °C, all these links are broken - so water is no longer a liquid and it
becomes a gas. In contrast, when water is cooled, the water molecules will have less and less energy
to move around, so will form even more bonds with each other. The water molecules will be no longer
free to move, so the water will become solid. This is ice.
Water molecules will always move in a direction from where there are more water molecules to where
there are less, if it can, by a process known as osmosis. For example, if a strong coffee is added to a
glass of water, the large number of water molecules in the water will redistribute themselves evenly in
the coffee, and the resulting solution will be an evenly distributed mixture of coffee and water….or a