Abstract: Sugar Solution Colour is determined by measurement of the absorbance of light of defined wavelength passing through a layer of sugar solution of defined mass concentration and thickness.
The method can be applied to raw sugars, affined raw sugars, white sugars and plantation white sugars provided that a filtered solution can be prepared by the procedure specified in the method. The method is designed for all sugars in the solution colour range up to 16 000 ICUMSA Units (IU) at pH 7.0.
This method is designated the ICUMSA Official (Reference) method. This is the method that ICUMSA recommends for the Determination of Colour of Sugars in any case of dispute.
However, for White Sugar colour it should be noted that Method GS2/3-10 gives equivalent results to this method up to a maximum value of 50 IU.
Precision data in terms of Repeatability and Reproducibility for sugars with solution colour in the range of 50 to 5000 ICUMSA Units (IU) at pH 7.0 are given in the table below.
The precision for higher colour sugars has not been determined.
Colour range (IU)
95% Repeatability r
95% Reproducibility R
50 to 200
200 to 500
500 to 1200
1200 to 2500
2500 to 5000
Online Access to ICUMSA Method GS9/1/2/3-8 (2011)
Access to the online Version of ICUMSA Method GS9/1/2/3-8 (2011) can be obtained from the Sugar Industry Website, operated by Bartens. The online access for two years costs EUR30 (+ 19 % VAT for German and EU citizens without EU VAT No.).