Fractionation of the Water-soluble Orange Pigments of Canned Skipjack Meat

Abstract

Water-soluble fractions of the orange coloring substance of canned skipjack meat were investigated. The water-soluble pigment was separated into six fractions by Sephadex G-15 gel filtration. The first and major fraction, the one having high molecular weight, exhibited an intensive orange color, strong biuret reaction, and weak ninhydrin reaction. The fractions with lower molecular weights had a low biuret and high ninhydrin reactivity.
The first fraction was precipitated in the presence of 10% trichloroacetic acid. Non-heat-coagulable fractions prepared from water-soluble proteins of raw skipjack meat, when cooked with G6P, produced orange pigments having a similar gel filtration behavior to that of the first fraction. A gel filtration pattern of pigments prepared from His-G6P mixture resembled that of the fractions with lower molecular weights which were mentioned above.
These results emphasize the importance of the water-soluble non-heat-coagulable proteins in the orange coloration of canned skipjack meat.