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What is isomaltose?

Isomaltose is a simple carbohydrate, a disaccharide composed of two glucose molecules connected with an alpha (1,6) glycosidic bond [1,2]. Isomaltose is not an essential nutrient, which means you do not need to get it from food to be healthy.

Isomaltose Formula

Isomaltose structre

Picture 1. Isomaltose structural formula

Nutrition Facts for Isomaltose

  • Calories per gram = ~2 [2]
  • Glycemic index = “low” [3]

Isomaltose Function

Isomaltose is a source of energy – it can provide less than 2 Calories per gram, which is about half as much as sucrose [2].

Isomaltose Sources

Isomaltose probably does not naturally occur in foods in significant amounts. It appears as an intermediate product of the starch digestion.

  • During caramelization of glucose, some isomaltulose is created.
  • Isomaltose, which is used as a sweetener in confections, candies, processed fruits and vegetables and in canned foods, can be artificially produced:
    • From sucrose by the help of the enzyme sucrose isomerase, obtained from the nonpathogenic bacterium Protaminobacter rubrum [2]
    • From high maltose syrup by the help of the enzyme transglucosidase
  • Corn syrup contains isomaltose, among other sugars.

Isomaltose and Dental Caries

Isomaltose has lower potential to cause tooth decay than sucrose [2].

Isomaltose Digestion

Isomaltose is digested on the surface of the small intestinal lining by the help of the enzymes isomaltase and maltase to two glucose molecules, which are then absorbed in the small intestine [9-p.412].

Congenital Sucrase-Isomaltase Deficiency

Individuals with a rare congenital sucrase-isomaltase deficiency (CSID) or sucrose-isomaltose malabsorption can have reduced ability to digest isomaltose and starch (which contains isomaltose) [4]. The unabsorbed isomaltose and sucrose act as osmotic laxatives. The main symptoms are abdominal bloating, excessive gas, chronic diarrhea, nausea and vomiting, which firstly appear in infants fed with formula that contains sucrose or isomaltose [10]. Diagnosis requires small intestinal endoscopy with biopsy.

Isomaltose and Cooking

  • Isomaltose is commercially available as a white crystalline powder [6,7].
  • Isomaltose is hygroscopic – it attracts moisture from the air [8].
  • Isomaltose is soluble in cold and hot water [6].
  • Isomaltose melting point is 208.4-320 °F (98-160 °C) [6,7].
  • Isomaltose is a reducing sugar [2] so it undergoes the Maillard browning reaction with amino acids.
  • Isomaltose is a fermentable sugar; it can be fermented by certain strains of brewer’s yeast [11].

Similar Nutrients

  • Maltose
  • Isomaltulose
  • Isomalt (a sugar alcohol)
  • Isomalto-oligosaccharides

  1. Isomaltose  PubChem
  2. Lee HC et al, 2008, Isomaltose Production by Modification of the Fructose-Binding Site on the Basis of the Predicted Structure of Sucrose Isomerase from “Protaminobacter rubrum”  PubMed Central
  3. PFNDAI BUlletin, May, 2006, Protein Foods and Nutrition Development Association of India
  4. Congenital sucrase-isomaltase deficiency  Genetics Home Reference
  5. Glucose-galactose malabsorption  Genetics Home Reference
  6. Isomaltose MSDS  Spectrumchemical.com
  7. Isomaltose  Chemical Book
  8. Isomaltose  Santa Cruz Biotechnology
  9. Debajyoti Das, 2012, Biochemistry, Fourteenth Edition
  10. de Zoeten EF et al, 2008, A 9-Month-Old Girl With Chronic Diarrhea  PubMed Central
  11. NPCS Board of Consultants & Engineers, Handbook on Fermented Foods and Chemicals

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