Interactions and antioxidant stability of sesamol in dry-emulsions: Interactions and antioxidant stability

International audienceDry emulsions prepared from saccharose (SAC),Labrafil M 1944 CS, sesamol (SEOH), and hydroxypropylmethylcellulose(HPMC) or sodium caseinate (SC)by grinding or dissolution, and different desiccation techniques(spray (SD)- or freeze (FD)-drying, or heating at60 C) were investigated to determine possible interactionsbetween mixture components. The goal of this study was todetermine the best formulation which will regenerate perfectly,after water dilution of dry emulsions, the initial liquidemulsion with the same characteristics that before drying.The morphological state of SAC and dry emulsions weredetermined by scanning electron microscopy analysis (SEM)analysis. Glass transition temperature, and melting (endothermic),decomposition (endothermic), oxidation (exothermic)peak temperatures and enthalpies were measured bydifferential scanning calorimetry (DSC). The antioxidantactivity of emulsions was evaluated through their ability toreduce 1,1-diphenyl-2-picrylhydrazil (DPPH) free radical.SEM analysis showed that SD-prepared, SC-containing dryemulsions formed better spherical particles with smoothsurface at about 5 lm diameter as compared to emulsioncontaining HPMC. These former emulsions also showedmore thermal stability by DSC. The combined results of thethree analytical techniques emphasized the importance of thedry emulsion process regarding the efficiency and the thermalstability of antioxidant substances. A specific physicaland/or chemical combination (such as hydrogen bond) sufficientlystable, at about 150 C, could be suggested when thetechnique used for dry emulsion preparation was SD. Afterwater dilution, this dry emulsion obtained from quaternarymixture: SAC, Labrafil, SEOH and SC, will regenerate theinitial liquid emulsion with the same characteristics thatbefore drying