Enhanced lycopene fortification in eggs using poultry feed containing a carotenoid-oil preparation derived from metabolically engineered baker’s yeast

Abstract

Carotenoids such as lycopene are important additives for food and animal feed due to their health-promoting effects as well as their industrial utility as color agents. However, the low bioavailability of lycopene from common sources limits its effective utilization as an additive in food and feed. Fortification of eggs is a promising strategy to increase dietary uptake of lycopene as well as enhance the pigmentation of egg yolk. Baker’s yeast, Saccharomyces cerevisiae, engineered to produce lycopene and beta-carotene, was examined as a supplement in poultry feed to replace synthetic dyes and fortify eggs with carotenoids. Improved bioavailability of lycopene was achieved using an oil-based formulation of carotenoids extracted from yeast. Feed supplemented with the carotenoid extract oil enhanced yolk color by as much as 4.5 points on the DSM color fan scale, compared to feed without added dyes, giving a color score of 10, equivalent to commercial feed. Feed containing 56 mg lycopene/kg resulted in the accumulation of 32.5 mg lycopene/g egg yolk, a value eight-fold higher than previous reports. These results demonstrate the utility of extracts from engineered yeast as a carotenoid supplement with high bioavailability for poultry feed, both as a color agent and to promote lycopene fortification.