Determination of the diastase (or 2-amylase) activity in honey.

Diastase is an enzyme catalysing the breakdown of starch that occurs in human and animal saliva. It is added to the honey by the bees.  Diastase is broken down when honey is heated and is therefore a criterion for the manner in which honey is treated.  

There is a legal minimum value of 8 Schade units.An exception is made for acacia and orange blossom honey: 3 Schade units.

 

Diastase is determined spectrophotometrically.  

The diastase number (expressed in Schade units) indicates how many grams of starch can be hydrolysed in 1 hour by the enzyme present in 1 gram of honey.  An insoluble and blue-coloured starch polymer is used as a substrate.  

The substrate is hydrolised by the diastase present in the honey and this produces blue, water-soluble parts determined spectrophotometrically at 620 nm.

The absorbance of the solution is directly proportional to the diastase activity of the sample.