What is Mucic Acid Test and its principle?
This is a specific test for galactose and is given by galactose as well as lactose, which is made up of galactose and glucose.
Principle
Oxidation of most monosaccharides by nitric acid yields soluble dicarboxylic acids. However, oxidation of galactose yields an insoluble mucic acid. Lactose will also yield a mucic acid, due to hydrolysis of the glycosidic linkage between its glucose and galactose subunits. Being insoluble, galactosaccharic acid crystals separate out.