Application of a dairy-based model system for mathematical mapping of diffusion of salt within rennet induced micellar casein concentrate matrices

Abstract

Salt migration or heterogeneity within cheese blocks influences ripening and quality parameters. A finite element model, based on the unidirectional mass transfer and Fick's second law, was employed to study the influence of changing brining conditions on the diffusion coefficients of salt through rennet-induced micellar casein concentrate model systems. Increasing the calcium ion (0–0.5% w/w) and protein (7.5–15% w/w), concentrations along with decreasing salting temperature (40-10 °C) and pH levels (5.10–6.50), significantly increased salt penetration where the diffusion coefficients ranged from about 1.40 × 10−10 to 8.70 × 10−10 (m2 s−1). Microscopic images revealed considerable changes to the homogeneity of protein structures, wall thickness of the casein-based network channels, and levels of dead-end structures—caused by manipulating the brining conditions. Computational 3D-maps were also prepared using the simulation software to illustrate salt migration. Overall, this study showed the potential for varying specific physicochemical parameters on controlling the migration rate of salt in dairy matrices.