Interactive effects of salt and fat reduction on composition, rheology and functional properties of mozzarella-style cheese

Owing to the risks associated with excessive dietary intake of fat and sodium, there is an increased consumer demand for food products, including cheese, with reduced fat and salt content. Research to date has focused mainly on the separate effects of reducing fat and salt. The primary objective of this study was to evaluate the combined effects of reducing fat from ~22% to 11% and salt from ~1.7% to 1.0%, on the composition, rheology and melting properties of mozzarella cheese. A secondary objective was to investigate the effect of reducing the calcium content of the reduced-fat, reduced-salt cheese as a means of improving its properties. Reducing fat and salt content led to higher levels of protein and moisture, lower contents of moisture-in-non-fat substances, fat-in-dry matter and salt-in-moisture. These changes coincided with lower water binding capacity, lower primary proteolysis and increased hardness and chewiness in the unheated cheese, and with a lower flow and higher work to extend (EW) the heated cheese. Lowering the calcium content of the reduced-fat reduced-salt cheese increased the levels of moisture and moisture-in-non-fat-substances, and reduced the protein content and the calcium-to-casein ratio; simultaneously, the unheated cheese had a higher water binding capacity, a reduced hardness and chewiness, while the heated cheese had higher flowability and a lower EW compared to the reduced-fat, reduced-salt cheese. Despite the mitigating effects of calcium reduction, the reduced-fat, reduced-salt, lower-calcium cheese was, nevertheless, firmer, harder, more cohesive and chewy, flowed less and had a higher EW than the full-fat, full-salt cheese.