Variations of Hausdorff Dimension and Selected Textural Indices of Cheddar and Gouda Cheeses During Storage

Two imported commercial cheeses (Cheddar and Gouda) were analyzed to characterize their textural changes during a storage period from 176 to 362 days at 4°C. Fractal dimension analysis was used to examine the structure of the cheeses, and a scaling model based on stress values was used to calculate fractal dimension (D_f) by the Hausdorff dimension count method. It was found that the variation of D_f of two cheeses showed a similar trend. When two cheeses were stored from 176 to 300 days, their D_f ranged from 2.37 to 2.43 for Cheddar or from 2.06 to 2.23 for Gouda cheeses. After that, the final values of D_f increased obviously to 2.87 (Cheddar cheese) or 2.63 (Gouda cheese) at the end of the storage period. The experiments carried out showed that the variation of D_f had a poor relationship with the changes of pH 4.6 soluble nitrogen and two instrumental textural indices (hardness and springiness) of the cheeses, especially in the late storage period, but the inhomogeneous cavities existing in the cheeses could be reflected by their D_f.