Influence of the oil-in water emulsion composition on the properties of the structure and functionality of particles obtained by spray drying

Abstract

Pomegranate seed oil (source of omega-5 unsaturated fatty acid) is importance to the food industry due to its beneficial health properties. However, unsaturated fatty acids are susceptible to oxidation, which makes the application of this oil into food products more difficult. An alternative to minimize these problems is the microencapsulation of the oil and the study of the properties of the structure (barrier) of the system; these properties are directly related to the protection and adequate release of the bioactive compound and they are still little studied. For this reason, the objective of this project is the encapsulation of pomegranate seed oil by oil in water (O/W) emulsion followed by spray-drying, using whey protein isolate microgels, whey protein isolate, maltodextrin DE-10, gum arabic and modified starch and the more detailed study of the structures (barriers) obtained for the system proposed here. The project will be divided into two steps: (1) Study of the properties of the particle structure, in which the treatments will be analyzed in relation to the yield and encapsulation efficiency, moisture, solubility, hygroscopicity, size and particle size distribution, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy, apparent, compacted and absolute density, porosity and adsorption isotherms and study of the properties of the structure of films formed by these emulsions, which they will be analyzed in relation to the thickness, DSC, wettability, surface hydrophobicity and morphology; and (2) Study of the encapsulated and free oil, in which the best treatments will be analyzed in relation to accelerated oxidation by Rancimat, stability of omega-5 fatty acids present in pomegranate seed oil and quantification of propanal and hexanal production levels in samples stored for 30 days. The encapsulation of this oil by the process proposed here should be explored to obtain innovative vehicles that will bring benefits to consumers' health and protection of the encapsulated compounds.