Effects on egg yolk colour of paprika or paprika combined with marigold flower extracts

COLOR-UP and COLOR-UP YELLOW-S were fed to a total of 144 twenty-five-week-old Charoen Pokphand brown laying hens to investigate whether yellow xanthophylls present in marigold flowers in combination with red xanthophylls from paprika fruit can further enhance egg yolk colour. The birds were randomly assigned to three groups: yellow corn basal diet control group (17.50 CP, 2750 kcal/kg ME); the 0.1% dietary paprika group; and the 0.1% dietary paprika plus 0.1% marigold group. Each group contained four replicates with 12 birds. Egg quality was recorded weekly from 25 to 28 weeks of age. Parameters did not show any difference except for egg yolk colour. Egg yolk colour scores were greater in the paprika group than in the control group (11.47 vs 8.64; P<0.05). Egg yolk colour scores of the paprika plus marigold group (12.17) were higher than those of the paprika group (P<0.05). Compared with the control, mean lightness value decreased in the paprika plus marigold group (P<0.05), suggesting a deep egg yolk colour in this group. Redness, yellowness and chroma were improved in both experimental groups (P<0.05). The spectral reflectance wavelength of egg yolk from the experimental groups increased between 600 and 700 nm, suggesting improved chroma. These results indicate that yellow xanthophylls from marigold flower extract (COLOR-UP YELLOWS®) in combination with red xanthophylls present in paprika (COLOR-UP®) can further enhance egg yolk colour and chroma.