ABSTRACT
The laying hen has a natural ability to deposit carotenoids into its egg yolks, especially the xanthophyll carotenoid lutein that is used commercially as an egg colorant. Can this ability to deposit carotenoids be used to enrich egg yolk provitamin A value? After a 10-d carotenoid depletion period in hens (n = 24), the effects of a 20-d intervention with high-ß-cryptoxanthin, high-ß-carotene, or typical yellow maize on color and carotenoid profile were compared with the effects of a white maize diet (n = 6/treatment). Eggs were collected every other day and yolks were analyzed by using a portable colorimeter to define the color space and by using an HPLC to determine the carotenoid profile. The high-ß-cryptoxanthin and yellow maize increased ß-cryptoxanthin in the yolk (0.55 ± 0.08 to 4.20 ± 0.56 nmol/g and 0.55 ± 0.08 to 1.06 ± 0.12 nmol/g, respectively; P < 0.001). Provitamin A equivalents increased in eggs from hens fed high-ß-cryptoxanthin maize (P < 0.001) but not the high-ß-carotene maize. The color (L*, a*, and b*) assessment of the yolks showed an increase in the high-ß-cryptoxanthin treatment for the red-green a* scale (P < 0.001) and a decrease for the light-dark L* scale (P < 0.001). No appreciable change was noted in the yellow-blue b* scale for the high-ß-cryptoxanthin treatment; but significant changes were noted for the yellow (P = 0.002) and high-ß-carotene maize (P = 0.005) treatments, which were most evident at the end of the washout period with white maize. ß-Cryptoxanthin-biofortified maize is a potential vehicle to elevate provitamin A equivalents and to enhance the color of yolks. This could lead to a human health benefit if widely adopted.
