STRUCTURAL DEVELOPMENT IN ICE-CREAM - DYNAMIC RHEOLOGICAL MEASUREMENTS

The influences of temperature, polysaccharide stabilizing agents and o verrun on the rheological properties of ice cream mix and ice cream we re measured using dynamic rheological techniques with a controlled str ess rheometer. Storage and loss moduli and tan delta all decreased sig nificantly with increasing temperature. Unstabilized samples demonstra ted significantly greater storage and loss moduli at temperatures < -8 C and tan delta at all temperatures than stabilized samples, however, polysaccharides increased mix viscosity and resulted in significant in creases in viscosity as the mix was concentrated. This indicated the i mportance of considering both ice and unfrozen phases in determining t he impact of stabilizers on ice cream theology. Increasing overrun fro m 20 to 60% increased the storage modulus significantly but had less e ffect on the loss modulus, especially in the stabilized samples. Howev er, as overrun increased, the maximum force required for large deforma tion decreased, emphasizing the need to consider the effects of small- scale versus large-scale deformation testing on structure. Dynamic rhe ological measurements can provide insights into the development of ice cream structure and are useful in complementing other techniques.