Hence, the relaxation time at 5% (w/w) lipid was about 4.5 s, corresponding to fc = 0.03 Hz; whereas 10% (w/w) lipid possessed longer relaxation time due to the smaller fc which could not be determined within the investigated frequencies. This means that if the relaxation time is smaller than the reciprocal of the rate of deformation (i.e. frequency), the system has sufficient time to relax to its equilibrium state, so that a fluid-like behavior is observed.