Changes in the fat globule membrane protein components of pasteurized milk caused by different homogenization conditions determined using a label-free proteomic approach

Abstract

Homogenization disrupts fat globules and reduces the size of fat globules. This processing method changes the components of milk fat globule membranes (MFGMs). In this work, changes in the MFGM protein profile, namely, the amount and number of proteins, of pasteurized milk caused by different homogenization conditions, including preheating temperature (prior to homogenization) and pressure, were investigated using a label-free proteomic approach, Kjeldahl nitrogen determination and SDS-PAGE. In total, 467 MFGM proteins in all the samples were identified. When the homogenization pressure was 30 MPa or the preheating temperature was 60 °C, the number of MFGM proteins was the highest. Preheating treatment caused a decrease in MFGM proteins. In raw milk, SDS-PAGE revealed the incorporation of MFGM proteins, such as XO, BTN, and ADPH, through disulphide bonds with the surface of the MFGM. In addition, the amount of β-CN and α-La increased with increasing homogenization pressure and preheating temperature, respectively. The two treatments also reduced the amount of CD 36, FABP, and PAS 6/7 that were involved in the reconstruction of MFGMs to some extent.