Effect of milk fat content on the viscoelasticity of mozzarella-type cheese curds

Abstract

The effect of fat content in cheese curds on their rheological properties were examined using dynamic shear measurements. Surplus fat addition to milk samples caused two distinct types of changes in the temperature dependence of the viscoelastic moduli of resultant curds. The first was a significant reduction in the moduli over a wide temperature range, which is attributed to the presence of liquefied fat globules within the milk protein network. The second was the excess contribution to the low-temperature moduli owing to the reinforcing effect of solidified fat globules. An upward shift in the sol-gel phase transition temperature driven by an increased fat content was also observed.Keywords Cheese rheology · Protein network · Sol-gel phase transition · Lipid globule · Dynamic shear modulus 1 IntroductionFat and protein are the two primary components in raw milk. The fat content of bovine milk is nearly 4% by weight, and it is dispersed in milk serum as globules with diameters that range from 0.2 µm to 15 µm, c.a. 4 µm on average [1]. Similar to fat globules, casein proteins (i.e., the major class of milk protein) exist as colloidal particles, known as casein micelles, and have diameters that range from 50 nm to 500 nm (average 120 nm). These colloidal domains comprise almost 80 % of the total solid content in milk. Therefore, their structural stability and interparticle interactions strongly affect the quality of dairy products such as cheese,

Effect of virgin coconut oil on properties of surimi gel

“…The lower values of G 0 for the samples incorporated with VCO at temperature above 25°C, compared to the control, could be due to the plasticizing effect of liquefied fat globules distributed in three dimensional protein network. This led to the reduction of the attractive forces between protein chains, thus making it more flexible (Shima and Tanimoto 2016). Subsequently, G 0 decreased at 40°C and then dropped to the minimum abruptly at around 50°C for all the samples.…”

The cheese matrix: Understanding the impact of cheese structure on aspects of cardiovascular health – A food science and a human nutrition perspective

“…Solid milk fat in cheese is known to act as reinforcing fillers, contributing to elastic properties of unheated cheese, whereas liquid fat acts as a plasticiser between casein strands, making cheese more soft and flexible (Rogers et␣al . 2010; Shima and Tanimoto, 2016). Age‐related changes, such as proteolysis and solubilisation of micellar calcium, as well as hydration of the casein strand reduce the rigidity of casein network.…”

Symposium review: Structure-function relationships in cheese

“…Lopez et al (2006) observed more than half (~54% of total fat content) of the milk fat present in Emmental cheese is in crystallized form at 4°C. Solid milk fat in cheese is known to act as reinforcing fillers, contributing to elastic properties of unheated cheese (Rogers et al, 2010;Shima and Tanimoto, 2016). Moreover, it has been suggested that the contact area between the casein increases with decreasing temperature as they expand at low temperature, probably due to weakening of hydrophobic interactions (Lucey et al, 2003).…”

“…During heating of cheese, the proportion of liquid fat increases dramatically; at ~40°C, almost all fat in cheese is in a liquid state (Lopez et al, 2006). Liquid fat acts as a plasticizer between casein strands, making cheese more soft and flexible (Shima and Tanimoto, 2016). Although fat has an important role in the initial softening of cheese during heating, it is now well accepted that the casein interactions have a major role on the melting properties of cheese.…”