Table 1. Analysis of volatile flavor substances from egg yolk of fresh egg and salted duck egg by GC-MS

Fresh duck egg yolk Control group salted duck egg yolk
Retention time (min) Compound name Retention time (min) Compound name
Esters Esters
 1 20.937 Methyl benzoate  1 20.960 Methyl benzoate
 2 17.872 Succinic acid, decyl tetrahydrofurfuryl ester
 3 22.708 1-Alanine, N-pentanoyl, myristyl ester
Acids Acids
 1 2.476 Acetic acid  1 2.720 Acetic acid
 2 22.255 5-(1,1-Dimethylethoxy)-2-thiophenecarboxylic acid  2 21.477 4-(Methylamino)butanoic acid
 3 25.123 Propyl-malonic acid  3 33.831 Pterin-6-carboxylic acid
 4 36.937 Octadec-9-enoic acid  4 36.930 6-Octadecenoic acid
 5 44.514 n-Hexadecanoic acid  5 44.507 n-Hexadecanoic acid
Alcohols Alcohols
nd nd  1 3.993 Ethanol
 2 7.138 2-Methyl-1-propanol
 3 10.103 3-Methyl-1-butanol
Ketones Ketones
 1 33.783 2’,4’-Dihydroxypropiophenone  1 23.324 (+)-2-Furanone
Aldehydes Aldehydes
 1 7.514 Furfural  1 7.554 3-Furfural
 2 7.631 3-Furfural  2 7.590 Furfural
 3 14.240 5-Methyl-2-furfuraldehyde  3 9.104 3-Methyl-butyraldehyde
 4 17.773 Benzaldehyde
Nitrogen compounds Nitrogen
 1 20.387 Methylpent-4-enylamine  1 35.336 Dimethylamine
 2 23.118 2,2-Dinitro-N-methylbutylamine
 3 24.376 Propionamide
 4 27.359 2-(Adamantan-1-yl)-1-methyl-ethylethylamine
 5 28.982 N-Formyl DL-alanine
Ethers Ethers
 1 41.176 Polyethylene glycol monolauryl ether  1 38.329 Octaethylene glycol monolauryl ether
Heterocyclic Heterocyclic
 1 7.469 3,5-Dimethylpyrazole  1 7.554 3,5-Dimethylpyrazole
 2 7.609 1,4-Dimethyl-pyrazole
Hydrocarbons Hydrocarbons
 1 25.632 3-Azabicyclo[3.2.2]nonane  1 30.798 2-Methylaminomethyl-1,3-dioxolane
 2 29.477 2-Methylaminomethyl-1,3-dioxolane  2 31.007 3-Azabicyclo[3.2.2]nonane
 3 28.071 2-Methylbicyclo[4.3.0]non-1(6)-ene  3 35.189 4-Methyl-1,3-dioxolane
Others Others
 1 8.702 Methyl cyanogen chloride  1 22.852 Naphthalene
GC-MS, gas chromatography-mass spectrometry.