VISCOSIMETRIC STUDIES ON ACID TYPE CHEESE TEXTURE

Abstract

The apparent viscosities of market acid type cheese samples, containing 7.5 to 9.8% of total proteins, 12.7 to 19.9% of dry matter and 0 to 40% fat in dry matter, were measured with a coaxial cylinder viscometer, over the temperature range 5 to 40°C and the rate of strain 9 to 482 s ‐1 for up to 2000 s. The logarithm of the apparent viscosity was a linear function of the logarithms of the rate of strain and of the shearing time. The activation energy of flow was about 35 to 40 kJ/mol for the nonfat cheese, while for cheese containing 30% fat in dry matter and for the temperature range between 15 and 20°C it increased to 100–130 kJ/mol. The logarithm of the apparent viscosity increased with increase of the protein content but the results were too scattered to allow prediction of the viscosity level for a single sample of known protein content.