Abstract
In this study, encapsulation of retinyl palmitate using the kneading method was investigated. The wall materials tested were mixtures of one of three naturally occurring cyclodextrins (CDs) and maltodextrin (MD) at low moisture content, and the MDs varied in their dextrose equivalent (DE) values. The retention and stability of retinyl palmitate encapsulated in a matrix prepared from a combination of α-CD and MD (DE = 11) were superior to those observed for all other combinations of CDs and MDs (DE = 17.5, 28, and47). The stabilities of the encapsulated retinyl palmitate fitted Avrami's equation. The rate constants of the MDs with low DE values were lower than those of MDs with high DE values. The degradation rate of the encapsulated retinyl palmitate depended on the MD content, possibly because high MD content suppressed oxygen diffusion into the wall material. In the α-CD/MD matrix, the MD content was a more important factor than the α-CD content for the stability of retinyl palmitate.
