Thermal properties of cheddar cheese: Experimental and modeling

Thermal properties (thermal conductivity, thermal diffusivity and heat capa city) of Cheddar cheese were measured as a function of cheese age and compo sition. The composition ranged from 30-60% moisture, 8-37% fat, and 22-36% protein (wet basis). The thermal conductivity and heat capacity ranged from 0.354-0.481 W/m degreesC and from 2.444-3.096 kJ/kg degreesC. Both thermal conductivity and heat capacity increased with moisture and protein content and decreased with fat content. The thermal diffusivity ranged from 1.07 x 10(-7) - 1.53 x 10(-7) m(2)/s. There was no significant relationship betwe en thermal diffusivity and moisture, fat and protein content of cheese. No statistically significant effect (at the 10% level) of age (0 to 28 wk) on thermal properties was observed. Models predicting thermal properties as a function of cheese composition were developed and their predictive ability was compared with that of empirical models available in the literature. In addition, several theoretical thermal conductivity models were evaluated fo r their usefulness with Cheddar cheese. Published thermal conductivity mode ls cannot accurately predict (mean error was from 3.4 to 42%) the thermal c onductivity of Cheddar cheese.