2000 Volume 37 Issue 2 Pages 77-85
The red-pigmented yeast, Phaffia rhodozyma, containing high concentration of astaxanthin (Ax) was evaluated as a dietary pigment source for egg yolk of laying hens fed on a low-carotenoid diet. Diets supplemented with the yeast to provide 0 to 16ppm Ax were fed for 4 weeks, while canthaxanthin (Cx), a synthetic pigment source, was added to diets at 0 to 1.5ppm as the comparing counterpart in 2 experiments. Roche color fan score and a* value on Chroma Meter increased linearly with the increase of logarithmic concentration of dietary Ax and Cx. Cx (Carophyll Red(R)) was 4 to 5 times as potent as Ax in the yeast for the pigmentation of egg yolk probably because of low digestibility of the yeast. Ax concentrations in plasma and egg yolk increased with dietary Ax concentration and the increases paralleled with the pigmentation of egg yolk. These results suggest that Phaffia yeast containing high concentration of Ax has the potential as natural pigment source for egg yolk of laying hens.
