The influence of fat globule membrane material on the microstructure of low-fat Cheddar cheese

Microstructural characteristics of low-fat Cheddar cheese differing in the content of milk fat globule membrane (MFGM) material achieved by addition of either buttermilk powder (BMP) or skim milk powder (SMP) to the cheese milk were investigated. Scanning electron microscopy and confocal scanning laser microscopy were used to study the cheese structure and the distribution of the starter culture and fat globules. Variations in the microstructure were observed relating to the MFGM content. The structure of the control cheese (made with the addition of SMP) was more irregular with inhomogeneous large voids. In contrast, cheese made with BMP addition had a homogeneous protein network with small voids, showing a smoother, more compact and less coarse structure accompanied by more pronounced fat globules that were uniformly scattered throughout the protein matrix. The starter bacteria were located within the protein networks in clusters that were distributed homogeneously throughout the cheese matrix regardless of treatment.