Reduction – the gain of electrons from an atom or molecule
Retrogradation/staling - the process by which the starch in a cooked and cooled starch-water mix
recrystallises and causes water to migrate out of the starch granules. It is the opposite process to
gelatinisation and is associated with the staling of bread.
Salt – a compound made up of one or more different ions, bonded together by their attraction of
Solid – the state of a substance in which all particles are touching and there is a repeated pattern
Solution - a liquid containing dissolved substances
Sugar – a molecule composed of one or more monosaccharides
Syneresis - loss of water from a gel due to increased interactions between the gelling molecules. It is
associated with the shrinkage of a gel.
Tensioactive molecule – a molecule containing both hydrophilic and hydrophobic parts, used to
Turgor - the rigid state of a cell resulting from pressure of the contents against the cell membrane
III/X - 1 (of 5)
More about culinary ingredients: Gelling Agents
How it works
When meat or fish is cooked for a long time in the presence of moist heat, a large quantity of the
collagen in the connective tissue will degrade and dissolve into the surrounding liquid.
When the surrounding liquid is hot, the gelatine and water molecules have quite a large amount of
energy, and they are constantly moving about each other.
If this solution is removed from the heat and left to cool, the gelatine molecules will have less energy
and will move more slowly and will begin to take on the form that they originally had in the connective
tissue – where they coil themselves around each other to form triple helixes, and as the individual coils
overlap, the slowly form a continuous network. This network is fairly strong, and prevents the ability of
the liquid molecules to flow – a gel has formed.
Left – gelatine in the form of collagen, pre cooking. Middle – dissolved gelatine. Right – gelatine
molecules forming a gel
Cooling the liquid