Invert sugar is a food additive that is produced by the application of heat and a bit of acid to sucrose. This causes hydrolysis of the sucrose, a process that breaks down the sucrose molecule (a compound sugar) into its component fructose and glucose molecules. This occurs naturally in the process of preserving fruit as jam and in the production of honey by bees.
Invert sugar is so named because of the effect a solution of it has on polarised light. When a solution of fructose and glucose is analyzed with a polarimeter, it rotates a plane of polarised light in the opposite direction to that of a sucrose solution. This quality can be used to measure the extent to which a sucrose solution is hydrolyzed.
Invert sugar has been adopted by the processed food industry for several physical characteristics that distinguish it from sucrose, including a sweeter taste, greater moisture retention, lessened tendency to crystallize, and a lowered freezing point. This makes it suitable for use in soft drinks, baked goods, jelly, and ice cream, among other things.
British Sugar, Product Information: Invert Sugar, <http://www.britishsugar.co.uk/bsweb/sfi/pages/invert.htm> (March 13, 2003)
The Sugar Association, Sugar Facts – Types of Sugar, <http://www.sugar.org/facts/types.html> (March 13, 2003)
Stephanie Dungan, Lecturer, Food Science & Technology 100A, Fall Quarter 2002, University of California at Davis, Attributes of Sugar Mixtures, <http://trc.ucdavis.edu/srdungan/fst100a/> (March 13, 2003)