Chemical composition and physical properties of 20% milk fat reformulated creams manufactured from reduced cholesterol butteroil
A reduced cholesterol butteroil was emulsified into skim milk, buttermilk, or buttermilk/butter-derived aqueous phase using different homogenization pressures and heat treatments to produce a 20% milk fat cream with a reduced cholesterol content. Transmission electron microscopic examination of reformulated cream emulsions showed an oil-in-water emulsion typical of milk lipid globules found in natural homogenized cream. Heat treatment (pasteurized and unpasteurized) and homogenization pressure (1500/500 PSI and 2000/500 PSI) had no effect on cream composition except for the significant effect of homogenization pressure on cholesterol content and the amount of phospholipid associated with the lipid globules. The formulations using buttermilk or buttermilk and butter-derived aqueous phase were the most similar in the amount of protein and phospholipid associated with the lipid globules when compared to a natural homogenized cream.
The viscosity. interfacial area of lipid globules. creaming stability, and feathering stability of the three formulations and a control at the two homogenization pressures were measured over a two week storage period at 7°C. The apparent viscosity and interfacial area of the different creams varied significantly with formulation but not with homogenization pressure or length of storage time (p ≤ 0.05). Creaming stability was significantly affected by formulation, homogenization pressure, and length of storage tinle (p S ≤.05). Feathering appeared to be unaffected by any of the treatment factors.
The reformulated cream using buttermilk and butter-derived aqueous phase was the closest in comparison to a natural homogenized cream in chelllical composition and physical properties. The ability to emulsify the reduced cholesterol butteroil into a stable cream emulsion may allow for the use of reduced cholesterol butteroil in fluid dairy products, ice cream, and cheese. Development of any full-fat product with a reduced cholesterol content will require a reformulation step until a method for cholesterol removal directly from fluid milk or cream is developed.