Effect of gelatinization and starch-emulsifier interactions on aroma release from starch-rich model systems

Release of selected volatile aldehyde compounds from starch-rich matrices was studied by headspace extraction, using solid-phase microextraction, and gas chromatography. Changes in the rheological properties of the starch-based matrices, due to starch concentration, gelatinization, and interactions with emulsifiers, were studied by steady shear and dynamic methods. The degree of volatile retention was found to depend on the compound properties, starch concentration, native structure of the granules, and presence of emulsifiers. The nongelatinized starch granules were more effective in lowering the volatile headspace quantities. Loss of the native structural integrity of the granules decreases the retention ability. For the nongelatinized starch dispersions, the more hydrophilic emulsifier showed a more pronounced effect on the matrix rheology and also on the aroma retention. A different behavior was observed for the gelatinized systems. Interpretation of the volatile release profiles was made on the basis of the matrix physical properties and interactions among components.