Size dependence of the salting process for dry salted sea cucumber (Stichopus japonicus)

• Effects of body weight on dry salting kinetics of sea cucumber were studied.
• Salting kinetics were significantly affected by the body weight of sea cucumber.
• Analytical solution with Bessel function well described the salt diffusion coefficient.
• The axial diffusion coefficients were higher than the radial diffusion coefficient.

The dry-salting kinetics of three groups of sea cucumber (SC) categorized by body weight as A (14.1–18.0 g), B (18.1–22.0 g) and C (22.1–26.0 g) were investigated. The effective salt diffusion coefficients (De) were estimated by mass transfer models describing dry–salting process of SC. The absolute values of the kinetic parameters for total and water weight changes during salting increased with decreasing SC weight. The values of De decreased with an increasing weight of SC because of the relatively thick thickness. De values calculated based on salt content were larger than those based on the liquid phase in both solutions. The effective salt diffusion coefficients based on a series of error functions (De1) and on the form of a trigonometric series (De2) varied from 1.37 to 1.95 and 3.91 to 5.55 × 10−10 m2/s, respectively. The axial diffusion coefficients (Dz) were higher than the radial diffusion coefficients (Dr).