Food Chemistry

Reducing sugar

A sugar with a free aldehyde or ketone group that can act as a reducing agent — glucose, fructose, lactose and maltose are reducing sugars. Sucrose is not, because both anomeric carbons are involved in the glycosidic bond.

Real-life application

Involved in the Maillard browning of bread crust and biscuits, and the basis of the test strips used to check sugar levels in some quality labs.

Related terms

Maillard reaction

Food Chemistry

A non-enzymatic browning reaction between a reducing sugar's carbonyl group and a free amino group of an amino acid or protein, producing melanoidin pigments and a wide range of flavour compounds.

Invert sugar

Food Chemistry

The equimolar mixture of glucose and fructose produced by hydrolysing sucrose, so called because the optical rotation inverts from positive to negative.

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Practise the subject behind the definition.

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