when heated to high enough temperatures, atoms within the monosaccharide molecule will start to
break away in a fairly violent manner, and the remaining structures will reorganise into new molecules,
which themselves may recombine to from new molecules.
These new molecules that are formed are responsible for generating both a large range of flavours
and a brown colour, and the process is known as caramelisation. The more the caramel is heated, the
browner it will become, and the less sweet it will taste (as the molecules responsible for the sweet
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taste are gradually broken down). A caramel should be removed as soon as it has developed a
desirable brown colour – over cooking a caramel will make it very dark, bitter and extremely thick.
Disaccharides are less reactive then monosaccharides (since their reactive group has been used in
forming the sugar dimmer). Therefore, disacharides like sucrose caramelise at a higher temperature
than the simple sugars because the disaccharide must be first broken down into its component
monosaccharides, which are sufficiently reactive to the undergo these characteristic reactions which
produce the caramels taste and colour, and this requires further heating. Sucrose will caramelise at
170°C, whereas glucose will caramelise at 150°C. (Fructose caramelises at the much lower
temperature of 105°C, just above the boiling point of water).
Making a caramel: In the kitchen caramels are most often made with sucrose. When a solution of
sucrose and water is heated, some of the sucrose molecules will acquire enough heat to break down
into its component glucose and fructose monomers. These monomers may lose some atoms and
rearrange to form new molecules, or else may recombine with other molecules to produce different
structures, for example the fructose monomers produced may themselves recombine to form fructose
dimmers, and these new dimers produced by the heat may then react further with glucose, or even
again with fructose. Some of these molecules may also break down into smaller and smaller parts.