Sucrose intolerance (also known as Congenital Sucrase-Isomaltase Deficiency (CSID) or Sucrase-isomaltase deficiency) occurs when sucrase is not secreted in the small intestine. With sucrose intolerance, the result of consuming sucrose is excess gas production and often diarrhea and malabsorption.
Sucrose itself is a non-reducing sugar, having the reducing aldehyde group involved in the glycosidic bond, and therefore will not test positive with Benedict's solution. In order to test for sucrose, the enzyme sucrase is mixed with the sample. The sucrose is hydrolysed into glucose and fructose, with glucose being a reducing sugar, which will test positive with Benedict's solution. Fructose can be isomerized to glucose by the addition of NaOH or other strong base.
