Though inverted sugar syrup can be made by heating table sugar in water alone, the reaction can be cane sugar syrup up by adding lemon juice, cream of tartar, or other catalysts, often without changing the flavor noticeably. The mixture of the two simple sugars is formed by the hydrolysis of sucrose.
This mixture’s optical rotation is opposite to that of the original sugar, which is why it is called an invert sugar. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Heating a mixture or solution of table sugar and water breaks the chemical bond that links together the two simple-sugar components. Once a sucrose solution has had some of its sucrose turned into glucose and fructose the solution is no longer said to be pure. A kind of light called plane polarized light can be shone through a sucrose solution as it is heated up for hydrolysis.
Such light has an ‘angle’ that can be measured using a tool called a polarimeter. When plane polarized light enters and exits a solution of pure sucrose its angle is rotated 66. As the sucrose is heated up and hydrolyzed the amount of glucose and fructose in the mixture increases and the optical rotation decreases. The existence of these forms is what gives rise to these chemicals’ optical properties. When any one form of a sugar is purified and put in water, it rapidly takes other forms of the same sugar.
This means that a solution of a pure sugar normally has all of its stereoisomers present in the solution in different amounts which usually do not change much. Water molecules do not have chirality, therefore they do not have any effect on the measurement of optical rotation. When plane polarized light enters a body of pure water its angle is no different than when it exits. Chemicals that, like water, have specific rotations that equal zero degrees are called ‘optically inactive’ chemicals and like water, they do not need to be considered when calculating optical rotation, outside of the concentration and path length. The overall optical rotation of a mixture of chemicals can be calculated if the proportion of the amount of each chemical in the solution is known. Common sugar can be inverted quickly by mixing sugar and citric acid or cream of tartar at a ratio of about 1000:1 by weight and adding water. If lemon juice which is about five percent citric acid by weight is used instead then the ratio becomes 50:1.