APPLICATION OF HEADSPACE-GAS CHROMATOGRAPHY-MASS SPECTROMETRY FOR CHARACTERIZATION OF VOLATILE COMPOUNDS IN CHICKEN EGGS

Abstract

Volatile compounds in chicken eggs under the cold chain system and non-cold chain system were characterized by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with chemometrics. According to a central composite design, the following optimum HS-SPME extraction conditions were obtained: extraction temperature of 65 oC, extraction time of 45 min and the amount of NaCl of 0.4 g. In comparison of their mass spectrum and linear retention index from HS-SPME-GC-MS analysis, major volatile compounds found in egg samples included toluene, hexanal, nonanal and other minor volatile compounds were heptanal, octanal, decanal, benzaldehyde, 1-octen-3-ol and 2-ethyl-1-hexanol, with the types and amounts of these volatile compounds in order: the non-cold chain system > cold chain system, the egg yolk > the egg white and the raw egg > soft boil egg. Using PCA analysis of all egg samples at 0-4 weeks, unclearly separated datasets obtained from eggs under the cold chain system imply that non-significant change in the amounts of volatile compounds in the eggs stored at 0-4 weeks. In addition, the non-cold chain system increase the amounts of volatile compounds in the eggs stored at 0-4 weeks. The HS-SPME-GC-MS method was also applied to investigate volatile compounds in commercial eggs and unpleasant eggs.