Effect of High Pressure Microfluidization on Microstructure of Mozzarella Cheese

Microstructure was compared in low-fat and full-fat mozzarella cheeses prepared from milk homogenized by microfluidization at various temperatures and pressures. Milk heated to 10, 43, or 54°C and containing 1.0 or 3.2 g fat/100 g fluid milk was homogenized at 34, 103, or 172 MPa prior to cheesemaking. Scanning electron microscopy was performed after 1 d and 6 wk of storage at 4°C. The micrographs showed that relatively large fat globules were dispersed throughout the casein matrix in each of the cheeses made from milk homogenized at 10°C, and in each of the nonhomogenized controls. As expected, fat globules were much smaller in the cheeses made from milk homogenized at the higher pressures. Increasing the milk temperature also caused the globule size to decrease since the fat became liquid and more easily fragmented. The results indicate that both homogenization temperature and pressure affect development of microstructure in mozzarella cheese.