Subprojeto 18 – Food microencapsulation – aspects of the organization and process optimization
Participantes: Míriam Dupas Hubinger – DEA-FEA-Unicamp
Nowadays, food microencapsulation is being studied by our research group, composed by 3 doctorate students, 2 master students and 1 undergraduate student. There are many techniques used to microencapsulate and the spray drying (which consists of transforming a fluid into a powder) is the one used by our group. Our studies involve microencapsulation of meat, mussel and fish residues protein hydrolysate (to be used as dietary supplements and/or natural flavors, in order to minimize the loss of volatile components which confer meat flavor); of açai (in order to increase anthocyanin stability); and of essential vegetable oils (in order to minimize oxidation and increase stability). Such a process can be defined as a process in which a substance of interest is covered by a material that totally or partially isolate it from the ambient, forming capsules. In the food industry, microencapsulation is being applied successfully in the protection of substances that are sensible to temperature, oxidation and moisture, such as acidifier, flavoring, colorants, enzymes, microorganisms, mineral salts, lipids, vitamins and amino acids. Thus, the use of microscopy techniques for evaluation of the microcapsules (morphology, particles size, core distribution inside the capsules, wall formation) would have great importance for our studies. Confocal laser scanning microscopy is being applied in many microencapsulation studies. In contrast to the scanning electron microscopy, where it is only possible to visualize the microcapsules surface, the confocal microscopy allows to observe the distribution of the encapsulated material (core) inside the microcapsules. Thus, it is possible to verify if the core is involved (encapsulated) by the wall material and how it is distributed inside the capsules (if they are uniformly distributed or not), which can affect the mechanism of release of the encapsulated component. Some microscopy techniques allow filming, which makes possible the evaluation of capsules breaking and core release. Another area of research that can make use of these techniques is the minimally processed fruits and vegetables, added of edible coatings, with the objective of extending these products shelf-life. With regard to the coated products, the goal is the utilization of techniques that provides tridimentional images to enable the study of characteristics such as uniformity, integrity, roughness ant coating thickness. For the osmotic dehydration treatment, is desired to visualize the solid penetration in the product. It was not found on the literature registers of the use of the techniques (multiphoton, FRAT, FRET, FLIM, STED, SHG, THG, laser microdissection, microcinematografia) for these applications.