Abstract #T59

# T59
Application of zinc and calcium acetate to precipitate milk fat globule membrane components from a dairy by-product.
N. Price*1, T. Fei1, S. Clark1, T. Wang1, 1Iowa State University, Ames, IA.

There has been great interest in developing isolated dairy lipid fractions that are rich in phospholipids (PLs) due to their health benefits and functional properties. Dairy by-products that contain elevated content of PLs and milk fat globule membrane (MFGM) proteins, which are currently being discarded, can be an excellent source for these isolates. The β stream (a by-product of skim milk and anhydrous milk fat production) is a perfect candidate since it contains a higher concentration of PLs and MFGM proteins than many other dairy by-products. In this study, we investigated an economically feasible processing method to obtain the valuable components from the β stream. Various zinc acetate and calcium acetate concentrations (0–200 mM), heat treatments (30 and 60°C), and pH adjustments (5.0–8.0) were investigated to determine how effectively PLs and proteins were precipitated into a pellet. With a subsequent extraction of lipids from the pellet using ethanol (90%, 70°C), a PLs-enriched lipid fraction and good quality dairy proteins were obtained. The optimum precipitation conditions for the β stream were zinc acetate (25 mM) at pH of 7.5 and 30°C, and calcium acetate (100 mM) at pH of 7.5 and 60°C. With the ethanol extraction, PLs recovery of 97.7% from the zinc acetate precipitate and 94.9% from calcium acetate precipitate were achieved.

Key Words: dairy lipid, phospholipid, by-product