Recipe for Honeycomb Candy
Caramelization
Caramelization is the oxidation of sugar, a process used extensively in cooking for the resulting nutty flavor and brown color. Caramelization is a type of non-enzymatic browning reaction. As the process occurs, volatile chemicals are released producing the characteristic caramel flavor. The reaction involves the removal of water (as steam) and the breakdown of the sugar. The caramelization reaction depends on the type of sugar. Sucrose and glucose caramelize around 160 °C (320 °F) and fructose caramelizes at 110 °C (230 °F).4
The highest rate of the color development is caused by fructose as caramelization of fructose starts at 110 °C. Baked goods made from honey or fructose syrup will, therefore, give a darker color.
Caramelization of sucrose starts with the melting of the sugar at high temperatures (see below) followed by foaming (boiling). Sucrose first decomposes into glucose and fructose. This is followed by a condensation step, in which the individual sugars lose water and react with each other. Hundreds of new aromatic compounds are formed having a range of complex flavors.
In the case of the caramelization of sucrose, three main product groups are formed: a dehydration product, caramelan C12H18O9; and two polymers, carmelen C36H50O25 and caramelin. The average molecular formula for caramelin C125H188O80.
Caramelization Products:
2C12H22O11 = 4H2O C24H36O18 Caramelan
3C12H22O11 = 8H2O C36H50O25 Caramelen
Continued heating yields caramelin C125H188O80
Caramelization continues to be a poorly understood process. Here is an overview:
- equilibration of anomeric and ring forms
- sucrose inversion to fructose and glucose
- condensation
- intramolecular bonding
- isomerization of aldoses to ketoses
- dehydration reactions
- fragmentation reactions
- unsaturated polymer formation4
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