Understanding salt diffusion in dairy-based systems: A model approach using rennet-coagulated micellar casein...

Area of Science:

• Food Science and Technology
• Dairy Science
• Physical Chemistry

Background:

• Salt diffusion is crucial for cheese production, influencing texture and flavor.
• Complex factors affect salt uptake, necessitating controlled study environments.
• Model cheese systems provide a platform to isolate and analyze these factors.

Purpose of the Study:

• To develop a model cheese system for studying salt diffusion.
• To evaluate the impact of calcium, fat, pH, and temperature on salt migration.
• To investigate the potential of using salty whey as a salting medium.

Main Methods:

• Utilized renneted gels from micellar casein concentrate as a model cheese.
• Assessed salt diffusion using Fick's second law.
• Analyzed protein structure changes using Fourier transform infrared spectroscopy.

Main Results:

• Increased calcium content (0-1% wt/wt) significantly enhanced salt penetration.
• Salting at 30°C improved salt diffusion compared to 20°C or 40°C.
• Salt diffusivity ranged from 3.1 × 10^-9 to 8.4 × 10^-9 m²/s; higher calcium promoted diffusion, while fat hindered it.
• Salty whey exhibited lower diffusivity than brine due to osmotic pressure and viscosity.

Conclusions:

• Model cheese systems effectively simulate salt diffusion dynamics.
• Calcium content and salting temperature are key modulators of salt uptake.
• Protein matrix structure and composition significantly influence salt migration pathways.