Whey proteins modify the phase transition of milk fat globule phospholipids

Abstract

The phospholipids extracted from milk fat globule membranes were composed of three major classes, phosphatidylethanolamines (37.2 %), phosphatidylcholines (30.0 %), sphingomyelin (28.2 %), and two minor classes, phosphatidylinositols (2.0 %) and phosphatidylserines (2.6 %). The thermograin showed that the extracted phospholipids presented a single wide-phase transition centered at 18.3 °C. The effects of temperature on the phase behaviour of milk phospholipids in the presence of β-lactoglobulin and α-lactalbumin have been studied at pH 4.0 and 7.0 (with or without calcium) using Fourier transform infrared spectroscopy. Principal component analysis carried out on the spectra in the 3 000-2 800 cm-1 region showed that the binding of the whey proteins to the phospholipids modified the lipid phase transition in different ways, depending on the in-solution protein. © Inra/Elsevier, Paris.