Abstract
The foaming power, drainage ratio and dynamic viscoelasticity were measured for soy milk foam samples, and an image analysis was performed by microscopy to investigate the characteristics of microbubble (MB) foam in comparison with bamix (ba) foam. The foaming power of the MB foam samples was higher, while the drainage ratio was lower than that of the ba foam samples, particularly for those samples with lower viscosity and longer blowing time. The high G′ value (elastic modulus) contributed to the high foaming power and stability of the MB foam samples. The low tan δ value (loss tangent) for the MB foam samples shows greater solidity than the ba foam samples. The bubble size of the MB foam samples was greater, while the size distribution was lower than the ba foam samples. The longitudinal changes in bubble size distribution and growth ratio for the MB foam samples were smaller than for the ba foam samples. The lower kinetic constants for bubble size growth of the MB foam samples are related to the lower drainage ratio, showing this relationship to be one of the factors stabilizing the MB foam.
