Flow Behaviour of Lard and of Its Fractions at 15°c. Relationship With Thbjrmal Behaviour and Chemical Composition

The rheological behaviour of lard and of its fractions at 15°C was studied by means of penetrometry and viscometry in order to characterize the variations of the yield value and of the viscosity in the temperature range from – 20 to 70°C. The Casson rheological model is suitable to describe the flow behaviour of these three fats until completely melted. The variations of the rheological parameters could be described by relationships of the form log x = a 103/T+ b. Comparison of the rheological behaviour, the thermal behaviour, determined by means of differential scanning calorimetry, and the solid fat content, determined by means of nuclear magnetic resonance, showed good relationship between the results over the whole melting range.