The type of gum arabic affects interactions with soluble pea protein in complex coacervation.

Complex coacervation is an encapsulation process involving two oppositely charged biopolymers. Since different compositions of gum arabic may affect its interaction with protein, we studied the complex coacervation of two types of gum arabic (GA) (Acacia senegal-GA1 and Acacia seyal-GA2) with soluble pea protein (SPP) through Zeta potential, turbidity, morphology, the secondary structure of SPP, UV/vis absorbance and thermodynamic parameters. The maximum formation of coacervates occurred at SPP:GA 3:1 (w/w) and pH 3.5-4.0 with changes in the secondary structure of SPP. GA1 combination resulted in higher binding constant, implying a stronger affinity between SPP and GA1. Entropy of 0.7 and 0.5 kJ/mol.K, and enthalpy of -151 and -95.5 kJ/mol were obtained for SPP:GA1 and SPP:GA2. The complex coacervation was spontaneous as proved by the negative values of the Gibbs free energy. GA1 resulted in stronger interactions with SPP, offering new alternatives for encapsulation of bioactive compounds.

Encapsulation of Plant-derived Bioactive Ingredients through Electrospraying for Nutraceuticals and Functional Foods Applications.

The electrospraying technique, which consists of electrohydrodynamic atomization of polymeric fluids, can be used to generate dry nano- and microparticles by subjecting a polymer solution, suspension or melt to a high voltage (typically in the range of 7-20 kV) electric field. This potential can be exploited for developing nano- and microencapsulation structures under mild temperature conditions. Thus, it constitutes a promising alternative to conventional microencapsulation techniques for sensitive ingredients, like most plant-derived bioactive compounds, especially for their application in the food sector. Given the importance of plants as one of the major sources of dietary bioactive compounds, significant attention has been recently paid to research the encapsulation of phytochemicals through novel techniques such as electrospraying, aiming to provide new tools for the development of innovative functional food products and nutraceuticals. In this review, the latest advances in the application of electrospraying for nano- and microencapsulation of phytochemicals are discussed, with a focus on their potential use in the food sector.

Self-assembled gelatin-ι-carrageenan encapsulation structures for intestinal-targeted release applications.

In this work, natural biopolymeric encapsulation structures were developed through the self-assembly of gelatin and ι-carrageenan in aqueous solutions. The interactions of this binary system and of a ternary system containing a polyphenol-rich extract were deeply explored for the development of intestinal delivery systems. The processing of the structures (extrusion vs. freeze-drying) greatly influenced release properties, explained by the specific interactions between gelatin and polyphenols, thus allowing for tuning the processing conditions depending on the desired target application. Release was further controlled by incorporating a divalent salt, giving raise to extract-loaded ι-carrageenan/gelatin capsules with adequate release profiles for intestinal targeted delivery. These results demonstrate the potential of exploiting biopolymer interactions for designing bioactive delivery systems using environmentally friendly processes which do not involve the use of toxic or harsh solvents or cross-linkers.

Microencapsulation structures based on protein-coated liposomes obtained through electrospraying for the stabilization and improved bioaccessibility of curcumin.

Novel food-grade hybrid encapsulation structures based on the entrapment of phosphatidylcholine liposomes, within a WPC matrix through electrospraying, were developed and used as delivery vehicles for curcumin. The loading capacity and encapsulation efficiency of the proposed system was studied, and the suitability of the approach to stabilize curcumin and increase its bioaccessibility was assessed. Results showed that the maximum loading capacity of the liposomes was around 1.5% of curcumin, although the loading capacity of the hybrid microencapsulation structures increased with the curcumin content by incorporation of curcumin microcrystals upon electrospraying. Microencapsulation of curcumin within the proposed hybrid structures significantly increased its bioaccessibility (∼1.7-fold) compared to the free compound, and could successfully stabilize it against degradation in PBS (pH=7.4). The proposed approach thus proved to be a promising alternative to produce powder-like functional ingredients.