Composition and functional properties of cholesterol reduced egg yolk

Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824-1224, USA.

The composition and functional properties of cholesterol reduced egg yolk (CREY) were compared to those of control egg yolk (EY). The CREY was prepared by absorbing cholesterol with beta-cyclodextrin after dilution and dissociation of granules at pH 10.5. The CREY contained less lipid and protein and more carbohydrate and ash than EY. Egg lipids were fractionated into triglycerides, cholesterol esters, free cholesterol, phosphatidyl choline, and phosphatidyl ethanolamine. Free and esterified cholesterol in CREY were reduced by 91.6 and 94.4%, respectively. Triglycerides were the major lipid class in CREY. The CREY contained more oleic acid and less linoleic acid than the control. Protein solubility in 0.1 and 0.6 M NaCl and sponge cake volume did not differ. The composition of proteins soluble in 0.6 M NaCl in both egg preparations were similar as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The electrophoretic profiles of proteins soluble in 0.1 M NaCl were similar, except that lipovitellin form EY was insoluble under these conditions. The CREY was less yellow than EY, as indicated by beta-carotene concentrations and Hunter b values. These results suggest that beta-cyclodextrin can be used to produce a low cholesterol egg product with compositional and functional properties similar to EY.