Characterizing pores in freeze-dried materials by fractal models and fractal dimensions

In order to represent structure and shape of pores in freeze-dried materials quantitatively, based on mercury intrusion, two fractal models of porous media were employed to characterize pores in freeze-dried bovine muscle and cured beef. The results show that the fractal dimensions are not reasonably presented when Menger sponge model is utilized to characterize the structures of pores in the samples, in which the characteristic scale of pores is 1～100 μm, although the linear relations in segments apparently exhibit. However, while the thermodynamic model is adopted, the fractal properties of the pores in the same samples are remarkably available, and the reasonable dimensions of the samples are obtained in the meantime. It deduces that the fractal features of pores in freeze-dried materials can be determined through the thermodynamic model.