COLOR - HISTORICAL
Mary An Godshall, Sugar Processing Research Institute, Inc.
Although it is frequently stated that color is one of the most important quality characteristics of raw and refined sugar, it is interesting to note that it was not until 1932 that color was formally addressed by ICUMSA as a subject. Color was mentioned in several earlier ICUMSA sessions, according to Frederick Bates, in his review of ICUMSA from 1897 to 1936 (Bates, 1942). It was evident that color was on the horizon in 1906 because mention was made of the raw sugar used by the Dutch for color standards and the need to develop unchangeable glass standards. After a report by the chairman on the substitution of samples of colored glasses for the Dutch standards and a discussion of the question, this remarkable conclusion was reached: “The commission unanimously expressed the wish that the valuation of sugar according to its color might soon be abandoned altogether, because this practice was to be condemned from the scientific as well as from the practical point of view.”
Of course, color was not abandoned as a quality criterion, and discussions have continued for more than one hundred years on what is color, the best way to measure it, how to interpret color results, sources of color, the effect of pH, the proper wavelength for measurement, how to get rid of it, and so on. Sugar color is difficult to define because it arises from several different sources and from the reaction of many precursors, so it is not one single, easily defined and measured compound, but rather a range of different, poorly defined compounds.
Bates, Frederick J., and Associates, 1942, Chapter 37, Appendix 2, Resume of the work of the
International Commission for Uniform Methods of Sugar Analysis, 1942, pp 767-779. IN:
Polarimetry, Saccharimetry and the Sugars, U.S. Government Printing Office, Washington, DC.