Inverted or invertsugar syrup is a mixture of glucose and fructose; it is obtained by splitting the disaccharide sucrose into these two components. Compared with its precursor, sucrose, inverted sugar is alluringly sweet and its products tend to retain moisture and are less prone to crystallization. Inverted sugar is therefore valued by bakers, who refer to the syrup as invert syrup.
Sucrose is a disaccharide, a molecule derived from two simple sugars (monosaccharides). In sucrose, the monosaccharide building blocks are fructose and glucose. The splitting of sucrose is a hydrolysis reaction. The hydrolysis can be induced simply by heating an aqueous solution of sucrose, but more commonly, catalysts are added to accelerate the conversion. The biological catalysts that are added are called sucrases (in animals) and invertases (in plants). Sucrases and invertases are types of glycoside hydrolase enzymes. Acid, such as lemon juice or cream of tartar, can also accelerate the conversion of sucrose to invert sugar.
The term "inverted" is derived from the practice of measuring the concentration of sugar syrup using a polarimeter. Plane polarized light, when passed through a sample of pure sucrose solution, is rotated to the right (optical rotation). As the solution is converted to a mixture of sucrose, fructose and glucose, the amount of rotation is reduced until (in a fully converted solution) the direction of rotation has changed (inverted) from right to left.
Hydrolysis is a chemical reaction in which a molecule breaks down by the addition of water. Hydrolysis of sucrose yields glucose and fructose about 85%; the reaction temperature can be maintained at 50–60 °C (122–140 °F).
Basic formula
by weight
|
| sucrose |
 100% |
| water |
50% |
| acid |
0.1% |
Neutralization
|
| cream of tartar |
 100% |
| baking soda |
45% |
Concentrating the syrup
and final temperature
|
| Sucrose |
Water |
Boiling point |
| 30% |
70% |
100 °C (212 °F) |
| 40% |
60% |
101 °C (214 °F) |
| 50% |
50% |
102 °C (216 °F) |
| 60% |
40% |
103 °C (217 °F) |
| 70% |
30% |
106 °C (223 °F) |
| 80% |
20% |
112 °C (234 °F) |
| 90% |
10% |
123 °C (253 °F) |
| 95% |
5% |
140 °C (284 °F) |
| 97% |
3% |
151 °C (304 °F) |
| 98.2% |
1.8% |
160 °C (320 °F) |
| 99.5% |
0.5% |
166 °C (331 °F) |
| Â 99.6%Â |
 0.4% |
 171 °C (340 °F) |
...
Wikipedia
