Lutein is widely used because of its excellent coloring ability. Lutein-containing materials are mainly used as feed additives in coloration of poultry, aquatic animals and birds. People prefer the yellow or orange yolk of poultry, soft red meat, and often judge the nutritional value and freshness of eggs from the color of egg yolk, biological materials containing lutein and zeaxanthin become the main source of natural feed colorants. In poultry fed on this diet, 70% of the pigment in eggs was lutein, and the coloring effect remained unchanged when the eggs were cooked. Because of its good coloring ability and stability and safety characteristics, many countries have listed lutein as food colorants, giving food a beautiful golden color.
Marigold extract for chicken feed has been proven effective at increasing the production of eggs. It was found that two grams per kilogram of feed improved the quality of egg yolks by enhancing the amount of lutein. While the total saturated, n-6 PUFA, and monounsaturated fatty acids in egg yolks were unchanged, lutein levels increased significantly. In addition, the n-6:n-3 PUFA ratio improved significantly in eggs fed with two grams of marigold extract per kilogram of feed.