The intercalation of flavouring compounds into layered double hydroxides

Abstract

Three commercial sugar substitutes (acesulfame K, cyclamate and saccharin), a bitterness inhibitor (ferulate) and a flavour potentiator (theobromine) have been intercalated into three common layered double hydroxide (LDH) hosts ([Ca₂Al(OH)₆]NO₃·yH₂O, [LiAl₂(OH)₆]Cl·yH₂O and [Mg₂Al(OH)₆]NO₃·yH₂O) by ion exchange. These LDH-biomolecule nanohybrids have been characterised using powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and solid state nuclear magnetic resonance spectroscopy which demonstrate complete intercalation of the anions into the LDH hosts. In vitro studies indicate release of these compounds' anions occurs in both deionised water and simulated saliva. Analysis of the release profiles using a number of kinetic models suggests a solution-dependent release mechanism. In some cases, release occurs at a largely constant rate up to the three-hour timepoint, suggesting that the nanocomposites could be highly suitable as carriers permitting gradual oral release of the guests in edible products.