Isolation and Characterization of Chicken Yolk Vitelline Membrane Lipids Using Eggs Enriched With Conjugated Linoleic Acid.
The vitelline membrane (VM) encloses the chicken egg yolk, separating it from albumen. The VM weakens during storage, and dietary lipid modification significantly affects its strength. However, no studies have characterize the fatty acyl residue (FA) composition of the VM, and reports of VM isolation and quantified lipid content are inconsistent. Therefore, the objectives of this study were: (1) to develop a washing and isolation method that removes residual yolk from VM without damage; (2) to determine the FA and lipid composition of CLA-rich egg yolk VM, relative to controls; (3) to determine the effect of 20 days of refrigeration on VM FA and lipid composition. To determine VM FA and lipid composition, 36 hens received either a corn-soybean meal-based control diet ("Control"), or the Control supplemented with either 10 % soy oil ("Soy control"), or 10 % CLA-rich soy oil ("CLA") for 30 days. VM were analyzed the day of collection ("fresh"), or after 20 days of refrigeration ("refrigerated"). There were no differences in FA compositions of fresh and refrigerated membranes within a treatment. CLA-rich yolk VM contains CLA, greater SFA, and significantly greater DHA relative to controls. Direct MALDI-TOF-MS identified 15 phosphatidylcholines, three phosphatidylethanolamines, one sphingomyelin, and 15 triacylglycerols in VM. Lipid species that showed significant differences among egg types included nine phosphatidylcholines and six triacylglycerols. MALDI analysis indicated significant differences in nine lipid classes on the VM inner layer. After refrigeration, five lipid classes on the inner layer and seven lipid classes on the outer layer had statistically significant differences among VM types.
Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR, 72704, USA. seshinn@uark.edu.
Sara Elizabeth
SE
Shinn
Department of Chemistry and Biochemistry, University of Arkansas, 1 University Avenue, Fayetteville, AR, 72701, USA.|University of Arkansas Statewide Mass Spectrometry Facility, 1260 West Maple Street, Fayetteville, AR, 72701, USA.
Rohana
R
Liyanage
Department of Chemistry and Biochemistry, University of Arkansas, 1 University Avenue, Fayetteville, AR, 72701, USA.|University of Arkansas Statewide Mass Spectrometry Facility, 1260 West Maple Street, Fayetteville, AR, 72701, USA.
Jackson O
JO
Lay
Department of Food Science, University of Arkansas, 2650 N. Young Avenue, Fayetteville, AR, 72704, USA.
Andrew
A
Proctor
D000821:Animal Feed; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004530:Egg Yolk / Q000378:metabolism; D019787:Linoleic Acid / Q000737:chemistry; D008563:Membrane Lipids / Q000032:analysis*; D012034:Refrigeration; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014817:Vitelline Membrane / Q000737:chemistry* / Q000378:metabolism
D008563:Membrane Lipids; D019787:Linoleic Acid
Conjugated linoleic acid; Direct MALDI-TOF MS; Egg yolk vitelline membrane; SEM-Fatty acyl residue composition; Sample preparation