Viscoelastic Properties of Part Skim Mozzarella Cheese: Effect of Calcium, Storage, and Test Temperature#

Abstract

Part skim Mozzarella cheeses with four levels of calcium (0.65% in control, 0.48% in T 1, 0.42% in T 2, and 0.35% in T 3) were manufactured on four separate occasions. Effect of varying calcium levels on viscoelastic properties of these cheeses was studied. Elastic (G′) and viscous (G′′) modulus were determined on day 1, 7, 15, and 30. Effect of increasing cheese temperature from 25 to 45°C during the test was also determined. Low calcium cheeses (0.35% in T 3 vs. 0.65% in control) had lower value of elastic (0.83 MPa vs. 1.89 MPa) and viscous modulus (0.57 MPa vs. 1.43 MPa). During storage, a decline in viscoelastic properties of the cheese was also noticed. After 30 days of storage, the elastic modulus of control and lowest calcium cheese (T 3) declined from 1.89 MPa to 1.69 MPa and from 0.83 to 0.55 MPa, respectively. Similar reduction in viscous modulus of control and lowest calcium cheeses (T 3) was also noticed after 30 days, i.e., values of G′′ declined from 1.43 to 1.25 MPa in control and from 0.57 to 0.27 MPa in T 3. A decline in elastic as well as viscous modulus with increase in cheese temperature during the test was observed. Values of elastic modulus were always higher than viscous modulus, indicating dominance of elastic nature of Mozzarella cheese. This information would help the manufacturers to produce cheeses with specific functional properties. #Published with the approval of Director of the South Dakota Agricultural Experiment Station as Publication Number 4321 of the Journal Series.