Controlled Release of Water Soluble Vitamins in High-Solid Polysaccharides with Co-Solutes

The work dealt with the diffusional mobility of water soluble vitamins (ascorbic acid and thiamin) embedded in high-solids carbohydrate matrices (high methoxy pectin/polydextrose and κ-carrageenan/glucose syrup). Thermomechanical analysis in the form of small-deformation dynamic oscillation in shear was utilised. The structural properties of the matrices were assessed in a temperature induced rubber-to-glass transformation. Colourimetric methods were employed to monitor the diffusion processes of the vitamins from the high-solid preparations to diffusion mediums. The relationship between mechanical properties of the carbohydrate matrix and vitamin mobility was assessed via the application of the combined framework of the free volume theory and the predictions of the reaction rate theory. Results argue that the transport of the micronutrients is governed by the structural relaxation of the high-solid matrices. These were further treated with the concept of Fickian diffusion coefficient to provide the rate of the bioactive compound motility within the present experimental settings.