Resumen de Estudio de la influencia de los diferentes parámetros involucrados en la microencapsulación mediante coacervación compleja
In 1931, the first research work related to microencapsulation was published, in which a microcapsule formation technology using gelatine as a wall material was described by a process called "coacervation".
The interest in this technology is based on the possibility of avoiding the degradation of the physicochemical and biological properties of substances exposed to conditions that are harmful by means of packing it under a polymeric wall, that can be of different thicknesses or characteristics, thus allowing to control the release of the microencapsulated substance.
In this thesis the manufacture of microcapsules of aromas by complex coacervation using gelatin and gum arabic as wall material is proposed. The process is based on 5 stages: Dissolution of gelatin and gum in the aqueous phase, microemulsion of the aroma in the aqueous phase in presence or absence of a surfactant, coacervation of the gelatin and gum, gelation of the coacervate forming the wall of the capsule and the crosslinking of the wall material by a crosslinking agent.
Initially, the research will focus on the development of a complex coacervation microencapsulation protocol that encapsulates much of the aroma of the system, obtaining relatively spherical microcapsules.
The microemulsion stage has the greatest influence on the final efficiency of the encapsulation and, therefore, this is the stage that has focused most interest in recent years. The interfacial phenomena linked to this process determine the particle size, the stability of the emulsion and the interaction of the components of the system at the oil-water interface, in this case, gelatin, gum and the possible surfactants present. This is why a part of the present thesis will focus on the study of the influence of different surfactants (SMA, SDS and Kolliphor®) on the morphology of the microcapsules and the efficiency of encapsulation.
The last part will focus on the study of the crosslinking process. Typically, microcapsules formed by complex coacervation using gelatin and gum arabic as wall materials have been cross-linked with glutaraldehyde or formaldehyde, substances with high toxicity. That is why recent studies have attempted to replace these aldehydes with the enzyme transglutaminase. To confirm whether transglutaminase is an option comparable to glutaraldehyde or formaldehyde, a study of the kinetics of cross-linking of the microcapsule wall will be carried out, obtaining the equations that regulate this process depending on the type of cross-linking agent studied.
