Tocopheryl acetate release from microcapsules of waxy maize starch

Naksit Panyoyai; Robert A Shanks; Stefan Kasapis

doi:10.1016/j.carbpol.2017.03.005

Tocopheryl acetate release from microcapsules of waxy maize starch

Carbohydr Polym. 2017 Jul 1:167:27-35. doi: 10.1016/j.carbpol.2017.03.005. Epub 2017 Mar 6.

Authors

Naksit Panyoyai¹, Robert A Shanks¹, Stefan Kasapis²

Affiliations

¹ School of Science, RMIT University, Bundoora West Campus, Plenty Road, Melbourne, Vic 3083, Australia.
² School of Science, RMIT University, Bundoora West Campus, Plenty Road, Melbourne, Vic 3083, Australia. Electronic address: stefan.kasapis@rmit.edu.au.

PMID: 28433162
DOI: 10.1016/j.carbpol.2017.03.005

Abstract

Diffusion coefficients are utilised to provide a realistic approach in the quantification of mass transport phenomena, which are important for the delivery of bioactivity from high-solid biopolymer systems. Following this mechanistic consideration, we employ spray drying to produce microcapsules of waxy maize starch that suspend homogeneously tocopheryl acetate. An array of physicochemical techniques including dynamic oscillation in-shear or compression mode, microDSC, WAXD, FTIR, scanning electron or optical microscopy, and UV-vis assays were utilised to relate structural properties of the macromolecular network to diffusivity of the bioactive compound. A modified version of the free-volume theory designed to address molecular diffusion was evaluated over a wide temperature range. Predictive capabilities were facilitated by proposing a mathematical relationship between diffusion coefficient of tocopheryl acetate and fractional free volume of waxy maize starch. Moreover, the theoretical approach is able to accurately describe the extent of cooperativity in the vitamin-biopolymer interaction that determines transport kinetics.

Keywords: Diffusional mobility; Glass transition temperature; Molecular coupling parameter; Tocopheryl acetate; Waxy maize starch.