Carotenoid Biofortification of Yolks to Produce More Nutritious Eggs

Overview

Biofortification increases the nutritional value of food crops by increasing the vitamin and mineral content. The objective of this research was to determine if a feed supplement including a high carotene-containing fruit in combination with high xanthophyll-containing petals could be used to produce a more nutritious Coturnix japonica (quail) egg that contains higher levels of both provitamin A (beta-carotene and beta-cryptoxanthin) and non-provitamin A (lutein and zeaxanthin) carotenoids important for human health and vision. Treatments included poultry feed only (control) and five supplements: marigold petals + tomato fruit, squash, squash + marigold, pumpkin, and pumpkin + marigold. Yolk color was measured using the yolk fan, and the carotenoid content of egg yolks was measured using high-performance liquid chromatography. All feed supplements resulted in darker yolks with higher yolk fan scores than control yolks. The darkest yolks were from the pumpkin + marigold diet, followed by the squash + marigold and the tomato + marigold diets. Egg yolks from all treatments containing marigolds had higher levels of lutein and zeaxanthin than the individual squash or pumpkin treatments. Pumpkin + marigold had the highest concentration of lutein and zeaxanthin in the yolks and significantly more beta-cryptoxanthin than control yolks. All the supplements resulted in beta-carotene deposition in the yolks, while control yolks had no detectable beta-carotene. Combining marigold petals with orange fruits resulted in the deposition of both provitamin A and non-provitamin A carotenoids in egg yolks, resulting in more nutritious eggs than quail diets with individual supplements.