pectins and citral

Citral-in-water emulsions were prepared with two different essential oil concentrations of 2.5 and 5.0% (w/w), then spray-dried in the presence of the same amount of maltodextrins (20%). The microcapsules were prepared with two different emulsifier compositions: monolayer microcapsules (ML) stabilized by sodium caseinate alone and layer-by-layer microcapsules (LBL) stabilized by sodium caseinate and pectin. The encapsulation efficiency was higher for LBL microcapsules (e.g. 99.6 ± 0.4% for 2.5% citral) than that for ML ones (e.g. 78.6 ± 0.6% for 2.5% citral) which confirm that the additional pectin layer was able to protect citral during the spray-drying process whatever citral concentration. Furthermore, our results showed that the antibacterial activity of the obtained microcapsules significantly depends on both citral concentration and interfacial membrane composition. The presence of two layers surrounding the citral droplets may result in a progressive and controlled release of the encapsulated citral.

Topics: Acyclic Monoterpenes; Anti-Infective Agents; Capsules; Caseins; Desiccation; Emulsions; Listeria; Microbial Sensitivity Tests; Monoterpenes; Oils, Volatile; Particle Size; Pectins; Polysaccharides; Staphylococcus aureus