The Effect of Milk Protein Concentration on the Microstructure and Textural Properties of Full Fat Cheddar Cheese During Ripening

The effect of varying the milk protein concentration using low-concentration factor ultrafiltration retentate (~3.7, 4, 4.8 and 5.8 % w/w protein) on Cheddar cheese during ripening was investigated. Quantitative analysis of the fat microstructure observed using confocal laser microscopy showed that the effect of the milk protein or time on the microstructure of the fat was minimal. Analysis of the protein sections showed a possible decrease in the branching of the protein network with time, as denoted by the smaller number of vertices, which correlated significantly with the level of trichloroacetic-soluble nitrogen (r = −0.66, P < 0.001) as well as the cohesiveness of the cheese (r = 0.70, P < 0.001). The hardness was different in cheese made with different milk protein concentrations during ripening. At week 26 of the maturation period, the cheeses made from the 4.8 and 5.8 % w/w milk protein were significantly harder than the cheese with no ultrafiltration retentate (UF) addition, which might appeal for particular end uses and selected consumers. This observation correlates with the thicker protein network seen for the cheeses with higher milk protein observed in the cryo-scanning electron microscopy images. Our findings indicate that milk protein concentration has little effect on the cheese microstructure and texture especially when an adequate ripening period is provided, suggesting that high cheese manufacturing throughput may be obtained via this method if maturation is adequate.