A comparative study on egg cholesterol contents and eggshell protoporphyrin and biliverdin pigments of different poultry species

Abstract

This study compared the cholesterol levels and shell pigments (protoporphyrin and biliverdin) of chicken (conventional and organic), quail, pheasant, and goose eggs. The material for the study was chicken (organic system-Lohmann Brown and conventional system-HyLine Brown) eggs, quail (Coturnix coturnix japonica), goose (local), and pheasant (Phasianus colchicus) eggs homogeneously selected with a subjective scoring. High-performance liquid chromatography with photodiode array detection was used to analyze the samples (HPLC-PDA). There were no significant differences in the yolk cholesterol content of eggs between species. Based on mg/g of yolk, different poultry species had comparable amounts of cholesterol. Quail eggshells contained significantly more protoporphyrin (81.92 M/g) than chicken (conventional-organic) and pheasant eggshells (P<0.01), but conventional chicken eggshells contained less protoporphyrin (10.73 M/g) than other species (P<0.01). Biliverdin was found only in the eggshells of quail (2.83 M/g) and pheasant (1.02 M/g) (P<0.01). It was observed that white shelled goose eggs had no detectable pigment. Research is required to elucidate the role of diet, age, stressor, strain, and housing systems on protoporphyrin and biliverdin pigment concentrations and cholesterol in table eggs and breeder eggs production.