Meat color modification in broiler chickens by feeding yeast Phaffia rhodozyma containing high concentrations of astaxanthin

Three experiments were conducted to evaluate the potential of Phaffia rhodozyma, a yeast containing high levels of astaxanthin (Ax), with or without cell-wall fracturing, to modify meat color in broiler chickens. Experimental diets supplemented with non-treated Phaffia yeast or cell-wall fractured yeast to provide up to 15, 20, and 30 ppm Ax were fed to 4- or 5-wk-old chickens for 14 or 21 d. Diets supplemented with Phaffia yeast did not influence performance of broilers or edible meat yields. Concerning color analysis of edible meats, for abdominal adipose tissues and-breast skin using Minolta reflectance colorimetry, the lightness (L* value) and yellowness (b* value) of the tissues were not meaningfully influenced by the yeast-supplemented diets. However, the redness (a* value) of all tissues measured was significantly increased by the yeast-supplemented diet. The effect was heightened by supplementing fractured yeasts in the broiler feed in proportion to dietary Ax concentration; Ax was detected in edible meats and liver in the concentration range from 0.1 to 1.1 mug/g tissue, and the concentration was mostly dependent on the dietary Ax concentration. These results show that the cell-wall fractured Phaffia yeast containing high concentrations of Ax can be a useful source of Ax for the modification of meat color, thus meeting consumer preferences in relation to the qualities of poultry meat.