Isolation and characterization of whey phospholipids

A freeze-dried whey powder was produced by microfiltration of Cheddar chees e whey. A 0.2-mu m ceramic membrane in a stainless steel housing unit was u sed to concentrate components >400 kDa present in the whey. The experimenta l whey powder, derived from Cheddar cheese whey, and a commercial whey powd er were subjected to proximate analysis, lipid classes, phospholipid classe s, and fatty acid compositional analyses. Commercial whey powder and commer cial soybean lecithin were subjected to an alcohol fractionation procedure in an effort to alter the ratio of phosphatidyl choline to phosphatidyl eth anolamine and the functionality of dairy phospholipids. The fractionation p rocedure produced an alcohol-insoluble fraction containing 84% phosphatidyl ethanolamine, whereas the alcohol-soluble fraction resulted in a decrease in the phosphatidyl choline to phosphatidyl ethanolamine ratio. The commerc ial whey contained a higher ratio of phospholipids to neutral lipids compar ed with the experimental whey. The classes of phospholipids present within the two wheys were similar, whereas the experimental whey contained a phosp hatidyl choline content twice that of the commercial whey, and the phosphol ipids composition of both wheys differed from the milk fat globule membrane . Comparison of the phospholipids and fatty acid composition of the wheys w ith the soy lecithin revealed that although the wheys were similar to each other, they differed from the soy lecithin in both the classes of phospholi pids present and in the fatty acid composition. These compositional differe nces may influence the functionality of whey phospholipids.