MEANING AND WORKING

ICUMSA is a world-wide body which brings together the activities of the National Committees for Sugar Analysis in more than thirty member countries. Work is carried out under various Subject headings, each headed by a Referee.
Methods are recommended for tentative approval by ICUMSA in the first instance. Upon meeting all of the Commission’s requirements, methods are accorded official status. Methods which are demonstrably useful and have found an established application, or which do not lend themselves to collaborative testing are given an Accepted status”

An ICUMSA rating is an international unit for expressing the purity of the sugar in solution, and is directly related to the colour of the sugar. Be aware that there are different types of ICUMSA units. For Brazilian sugar, the lower the ICUMSA figure the whiter the sugar.
However, this is not the case in the E.U. for some unknown reason, which has been the subject of much discussion. SGS of Sao Paulo has published specifications for ICUMSA numbers for E.U. product which run contrary to the Brazilian specifications; for example, in Brazil SGS has an ICUMSA rating of 45 rbu for refined, indicating the highest quality, with other grades of lower quality (such as Special Extra Crystal) having a higher ICUMSA of 150 and so forth.
This rating method is confirmed by the Institute of Sugar and Alcohol in Brazil.

The TU is heavily dependent upon “ash points”, which are defined as “Conductivity ash, % , expressed to three decimal places” (British Sugar Corp., Central Laboratory, ICUMSA Headquarters). Further used to weight the TU is “reflectance Grade Colour” and “Solution Colour” or “Filtered Colour” as it is referred to, which have formulas for determination equally confusing as the one for “Ash Points”. Thus, as you see, this is not easily understood by the novice.