EFFECTS OF SUNLIGHT ILLUMINATION OF MARIGOLD FLOWER MEALS ON EGG-YOLKPIGMENTATION

The effect of sunlight illumination of marigold flower meal on the pig mentation of feed for laying hens and of their resulting egg yolks was evaluated by high-performance liquid chromatography and by subjective and light reflectance colorimetry techniques. Illumination did not ha ve an effect on the identity of carotenoids in the flower meal. Intere stingly, illuminated marigold flower meals yielded an oleoresin with a higher all-trans-zeaxanthin level, with respect to meals kept in dark ness. A higher level of all-trans-zeaxanthin was also present in feed pigmented with that oleoresin. Additionally, this pigmented feed showe d the best color values and resulted in egg yolks with good color; rem arkably, these egg yolks had a low pigment content with respect to con trol treatments. Thus, sunlight illumination of marigold flower meal s howed a positive effect an egg yolk color; the main factors contributi ng to this effect were not the identity or quantity of carotenoids in laying hen feed or egg yolks, but rather other as yet unidentified mar igold component(s) which was (were). somehow influenced by sunlight il lumination.