The effect of high-pressure homogenisation on the size of milk fat globules and MFGM composition in sweet buttermilk and milk

Effects of high-pressure homogenisation (HPH, 100 MPa) at different temperatures (4-60 degrees C) or conventional homogenisation (20 MPa, 60 degrees C) on size of milk fat globules (D32) and content of protein and phospholipids in milk fat globule membrane (MFGM) in standardised milk, buttermilk and a mixture of milk and buttermilk were compared. HPH decreased D32 and promoted the adsorption of casein at > 4 degrees C, b-lactoglobulin in milk and buttermilk at > 40 degrees C and >20 degrees C, respectively, and a-lactalbumin at 60 degrees C, on the surface of milk fat globules. The content of milk proteins adsorbed on MFGM increased with increasing temperature and pressure in milk, and, to a lesser extent, in buttermilk. The content of phospholipids in buttermilk was 2-fold higher than in milk. HPH influenced the content of sphingomyelin (increased) and phosphatidylcholine (decreased) in MFGM in milk. Conventional homogenisation increased the phosphatidylethanolamine content in MFGM in buttermilk. (C) 2020 Elsevier Ltd. All rights reserved.