Egg yolk color as affected by saponification of different natural pigmenting sources

Abstract

Two experiments were conducted to study the influence of saponification of various yellow, red, or yellow and red xanthophylls from marigold flower and paprika fruit included at graded levels on egg yolk coloration in table and breaking eggs. Pigmentation was measured visually by the Roche yolk color fan, a subjective method, and by reflectance colorimetry, using a HunterLab MiniScan XE colorimeter, an objective method. Reflectance colorimetric a/b (redness to yellowness) ratio appeared to be a good variable to objectively measure egg yolk color on a practical basis. Results indicate that saponification of xanthophylls increased its pigmenting capacity in egg yolk. The effectiveness of saponification was more evident as a darker color of egg yolk was pursued. Both in table and in breaking eggs, the pigmenting capacity of saponified xanthophylls is at least 1.5-fold that of nonsaponified xanthophylls.