| Clinical data | |
|---|---|
| Pregnancy cat. | ? |
| Legal status | ? |
| Identifiers | |
| ATC code | ? |
| ChEMBL | CHEMBL1201647 |
| Chemical data | |
| Formula | C12H22O11 |
| Mol. mass | 342.30 g/mol |
| (what is this?) (verify) |
|
Inverted or invert[1] sugar syrup is a mixture of glucose and fructose; it is obtained by splitting sucrose into these two components. Compared with its precursor, sucrose, inverted sugar is sweeter and its products tend to remain more moist and are less prone to crystallisation. Inverted sugar is therefore valued by bakers, who refer to the syrup as trimoline or invert syrup.[2]
In technical terms, sucrose is a disaccharide, which means that it is a molecule derived from two simple sugars (monosaccharides). In the case of sucrose, these 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 occurs in lemon juice or cream of tartar, also accelerates the conversion of sucrose to invert.
Contents |
The term 'inverted' is derived from the method 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).
Inverted sugar syrup can be easily made by adding roughly one gram of citric acid or ascorbic acid per kilogram of sugar. Cream of tartar (one gram per kilogram) or fresh lemon juice (10 millilitres per kilogram) may also be used.
The mixture is boiled for 20 minutes, and will convert enough of the sucrose to effectively prevent crystallization, without giving a noticeably sour taste. Invert sugar syrup may also be produced without the use of acids or enzymes by thermal means alone: two parts granulated sucrose and one part water simmered for five to seven minutes will convert a modest portion to invert sugar.
All inverted sugar syrups are created from hydrolysing sucrose to glucose (dextrose) and fructose by heating a sucrose solution, then relying on time alone, with the catalytic properties of an acid or enzymes used to speed the reaction. Commercially prepared acid catalysed solutions are neutralised when the desired level of inversion is reached.
All constituent sugars (sucrose, glucose and fructose) support fermentation, so invert sugar solutions may be fermented as readily as sucrose solutions.
Invert sugar has a lower water activity than that of sucrose, so it provides more powerful preserving qualities (a longer shelf life) to products that use it.
The shelf life of partial inverts is approximately six months, depending on storage and climatic conditions. Crystallised invert sugar solutions may be restored to their liquid state by gently heating.