Sensitivity analysis on the release of food active compounds from viscoelastic matrices

Abstract

The release characteristics of food active compounds from viscoelastic matrices were studied through a sensitivity analysis of a mechanistic mathematical model. The mathematical model considered water, encapsulating polymeric matrix (matrix) and active (dissolved and non-dissolved into the matrix) as the main species, while diffusion, swelling, erosion and dissolution of non-dissolved active were regarded as the main phenomena. Dimensionless parameters based on characteristic times of the phenomena involved were obtained when the model equations were non-dimensionalized and scaled. The dimensionless parameters are: swelling (Γw, δσ, ζ), erosion (δw), matrix depolymerization (δM), dissolution (δs), solubility (θ) and diffusion of active compound (γA, αA), and external mass transfer of water (Λ). These dimensionless parameters were used to set up a reference condition (dimensionless parameters equal to one) and disturbed conditions (dimensionless parameters changing from 0.1 to 100) to analyze the relative effect on the model outputs (volume-averaged fractions of released active, absorbed water, matrix stress and remaining polymer). In general, δs affected the most the release kinetics of active followed by Λ, δw, and θ. The rest of the parameters had a smaller impact on the release kinetics, while γA and the matrix viscous behavior had marginal effects.