Objective spectrophotometric color measurement

Objective spectrophotometric color measurement, as described in AOCS Official Method Cc 13 50 (Firestone, 1998), gives results that are in general highly correlated with Lovibond color, although wide discrepancies occur with some oils (O Brien, 2003). Method Cc 13-50 is stated to be applicable to cottonseed, soybean and peanut oils, and requires revision to accommodate the use of double beam spectrophotometers. Its applicability to milk fat is not known. 

The indirect methods discussed thus far have dealt with measurement of color only as it can be correlated with physical characteristics of materials and the effect of these materials on radiant energy. As has been pointed out, the reflectance spectro-photometric curve describes a property of the material. A change in the reflectance spectrophotometric properties may not always result in a change in visual color. The reason is that color of the object is not an unchangeable characteristic of the object itself, dependent only upon these reflectance properties, but is also dependent upon the quality of the illuminating light and the sensitivity of the observer s eye. Thus the measurement and description of visual color are psychophysical problems... 

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