As a stabilizer, sugar also has antioxidant properties.
Tests have shown that a sugar solution can prevent rust from forming on iron surfaces.
It has also been demonstrated that glucose syrup effectively prevents flavour degradation of fruit in jams exposed to oxygen.
In addition, sugar slows the rancidification of vegetable fats in biscuits.
A natural preserve !
For centuries sugar has been used as a natural means of preserving fruit in the form of jam, bottled fruit or syrups, and sweet condensed milk.
The reason is that the stability of a food largely depends on how much water it contains, measured by its activity of water or aw, and more specifically, how the water binds with other ingredients.
Once dissolved, sugar binds the water molecules in fruit to prevent flavour degradation or the growth of microorganisms, such as yeast, bacteria and mould.
This means that the fruit has been “stabilized”.
Sugar is still the main agent for reducing the activity of water in jam and chocolate. Sugar also has the task of making jams set. A chemist will tell you that it enables the gel formed by the pectin molecules in the fruit to set by fixing the water molecules surrounding them.
Candied fruit is made using the confisage technique. Confisage consists of steeping whole fruits or fruit segments in increasing concentrations of sugar solution. Large amounts of water are transferred to the solution and the fruit absorbs the sugar.