In the early 1950's, a symposium entitled Color in Foods was arranged under the aegis of the National Academy of Sciences, National Research Council. The proceedings of that symposium have not to this day been superseded by a more up-to-date consideration of the state of knowledge as it has evolved since then.
At that time, considerable discussion was focused on the question of the validity of relating objective data to some visually determined and presumably imprecise scale. Because the opportunity has not presented itself to continue the vigorous exploration of this and other unresolved questions, the reservations and recommendations expressed in the proceedings stand unchallenged.
It is the purpose of this report to present a detailed discussion of the procedural framework developed by us to provide the basis for developing solutions for specific commodities and for specific purposes. The essentials include the development of model systems constructed to vary in known and controlled fashion along the requisite dimensions of color; the determination of optimum conditions for analyzing samples precisely and reproducibly for changes in physical and chemical properties which underlie changes in perceived color; the definition and construction of psychological scales which provide data relevant to the case in point; and finally, the demonstration of a highly significant relationship between visual evaluations and physically determined quantities. Thus, for different products, the same conceptual model is used; yet the procedural details may differ widely depending on the constraints imposed by physical and chemical characteristics of the sample and the specific requirements of the case. The feasibility of the approach will be explored with reference to actual examples.