Applications Of Electro-Optical Techniques To Nondestructive Quality Evaluation Of Foods

Although man has been judging produce quality via light since antiquity, it has been only during the past 50 years that detectors other than the human eye have been available. The initial significance of photoelectric detectors was in providing instruments which brought new objectivity into the evaluation of color and appearance. The progress in objectively rating the color of agricultural products during the period 1930 to 1960 is covered in the publications of Dorothy Nickerson (1946). During this period numerous color specifications for agricultural products were written. Many color standards, such as the Munsell "Soil Color Charts," were prepared. The methods for visually rating color are well developed and are fully described in books on color; e.g. Judd and Wyszecki (1975) and literature of the Munsell Co., Baltimore, Md. Limitations in this method of evaluating color are basically human factors. Efforts at eliminating these limitations brought about widespread use of the color difference meter.