Curing and diffusion coefficient study in pastırma, a Turkish traditional meat product

Area of Science:

• Food Science and Technology
• Meat Science
• Food Engineering

Background:

• Traditional meat curing processes like pastırma production involve complex mass transfer phenomena.
• Understanding the dynamics of moisture, salt, and water activity is crucial for product quality and safety.
• Quantifying salt diffusion is essential for optimizing curing times and predicting product stability.

Purpose of the Study:

• To determine the changes in water activity (a(w)), moisture content, and salt content during the curing of pastırma.
• To calculate the effective salt diffusion coefficients (D(eff)) in pastırma during the curing process.
• To model the salt diffusion using Fick's second law for pastırma slices.

Main Methods:

• Pastırma samples were subjected to a controlled curing process for 48 hours.
• Measurements of water activity (a(w)), moisture content, and salt content were taken at intervals.
• The analytical solution of Fick's second equation was applied to determine salt D(eff) values, assuming an endless slice geometry.

Main Results:

• Water activity (a(w)) decreased to 0.942 by the end of curing.
• Average moisture content reduced from 74.56% to 66.64%.
• Average salt content increased to 15.65 g NaCl/100 g dry matter within 48 hours.
• Effective salt diffusion coefficients (D(eff)) ranged from 1.49×10(-9) to 4.08×10(-9) m(2)/s.

Conclusions:

• The curing process significantly alters the physicochemical properties of pastırma, reducing moisture and water activity while increasing salt content.
• The calculated salt diffusion coefficients provide valuable kinetic data for understanding and optimizing pastırma production.
• The application of Fick's law offers a robust method for quantifying salt penetration in cured meat products.