Diffusion in Biological Media: A Comprehensive Numerical-Analytical Study via Surface Analysis and Diffusivities Calculation

Abstract

This study examines the diffusion of substances through biological porous materials (analytically and numerically) via diffusion coefficients calculation and surface analysis. The research proposes a sweetening Bing-type cherries (Prunus avium) process using a combination of sucrose and xylitol and a staining technique utilising erythrosine and red gardenia at varying concentrations (119, 238 and 357 ppm) and temperatures (40, 50 and 60°C). Given the fruit's epidermis resistance, the effective diffusivities of skin were inferior to those in flesh. Temperature and concentration synergise in enhancing diffusion coefficients and dye penetration within the food matrix (357 ppm and 60°C). Red gardenia displayed significant temperature-dependent variation (p = 0.019), whereas erythrosine dye remained stable by temperature changes (p>0.05). Gardenia's effective diffusivities in cherry flesh and skin, at 357 ppm and 60°C, 2.43E-08 and 4.12E-09 m2/s, respectively, significantly differed from those obtained at lower temperatures and concentrations. The results emphasise the importance of considering temperature-concentration effects on mass transfer calculations for food colouring processes.