Frozen cheese curd as an intermediate for cheese making – homogenization as a tool to regain techno-functional properties

Abstract

AbstractThis study investigated the effect of milk homogenization/fat globule size on the plasticization of fresh and frozen stored cheese curd and its respective oiling-off behavior. The cheese was frozen either slowly in a freezing chamber or quickly with liquid nitrogen to study the influence of freezing, frozen storage, and thawing. For non-frozen cheese curd, a one-stage homogenization at 2 MPa before renneting still leads to plasticization, while relative oiling off is reduced from 2.6 to 1.9%. This was explained by reduced fat globule size and an increased surface area covered by whey proteins and casein, which is denser and more stable than the native fat globule membrane. For homogenization pressures above 4 MPa, no plasticization was observed. However, freezing and thawing counteract mild homogenization, so minor oiling off occurs, and flowability is enhanced. Extending frozen storage time up to 3 months did not result in more oiling off or higher tan δ values. Moreover, there was no significant effect between the two freezing methods. In conclusion, freezing and frozen storage for up to 3 months is a valid method to preserve cheese curd as techno-functional properties are regained after thawing.