Comparison of visual and automated colorimeters: an international collaborative study

Color as a fundamental quality of edible oils has been determined primarily by visual comparison methods for many decades. The automatic colorimeters introduced recently made it possible to replace the manually operated visual color instrument, which requires experience to master and is often subject to operator variabilities. A previous study with an automatic colorimeter, Colourscan, to measure the colors of refined and refined bleached cottonseed oils showed good agreement (r2=0.99) with visual color measurements by means of the Lovibond‐AOCS Color Scale. The current work is to establish a broad‐scale correlation between the automated colorimeter and visual color measurements. In this international effort, factory‐processed refined and refined, bleached, deodorized (RBD) canola, corn, cottonseed, peanut, sunflower and soybean oils, as well as refined palm olein, RBD palm oil, and washed, dried, filtered and deodorized tallow were used. A total of 14 laboratories from the United States and Canada, and 16 laboratories from 12 countries outside of North America, participated in this collaborative study. The results of this study, with statistical analyses, are reported.