VISCOELASTIC PROPERTIES OF BUTTER

摘要

VISCOELASTIC PROPERTIES were studied on butters prepared from fractionated high-melting triglyceride (HMT) and anhydrous milk fat (AMF). The elastic moduli (G'), the viscous moduli (G '') and the complex viscosities (eta*) were determined as functions of angular frequency (omega). With increasing frequency, eta* and G '' decreased while G' increased. Higher G', G '' and eta* values were obtained for HMT butter, indicative of its firmer characteristics. Shift factors, determined using method of reduced variables, followed the Arrhenius model, from which the energies of activation were calculated. Power law intercepts, determined by relating G* to omega, exhibited a semi-logarithmic inverse relationship with temperature. Slight increase in power law intercepts was observed on storage due to thixotropic rearrangements of fat crystals. [References: 18]