Reducing sugar

Reducing sugar

A Reducing sugar is a type of sugar that has the ability to act as a reducing agent because it has a free aldehyde group or a free ketone group. All monosaccharides are reducing sugars, along with some disaccharides, some oligosaccharides, and some polysaccharides. The reducing properties of these sugars can be observed in the Benedict's test or Fehling's test.

Chemistry

Reducing sugars have free aldehyde or ketone groups, which allow them to reduce copper(II) ions to copper(I) oxide, a red precipitate in the Benedict's or Fehling's tests. This reaction is used to detect reducing sugars but is not a definitive test for glucose because other sugars may be present.

Examples

All monosaccharides, such as glucose, fructose, and galactose, are reducing sugars. Some disaccharides, like lactose and maltose, are also reducing sugars. However, sucrose is not a reducing sugar.

Health implications

Reducing sugars can react with amino acids in the Maillard reaction, a form of non-enzymatic browning. This reaction is responsible for the browning of cooked foods and also has implications for human health, as it can produce advanced glycation end products (AGEs) that are implicated in many chronic diseases, such as diabetes and Alzheimer's disease.

See also

• Monosaccharide
• Disaccharide
• Oligosaccharide
• Polysaccharide
• Maillard reaction
• Advanced glycation end-product

Reducing_sugar

• 
  D-glucose lineal
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  Maltose Gleichgewicht