Tannin-rich extracts improve the performance of amidated pectin as an alternative microencapsulation matrix to alginate

Abstract

Microencapsulation of tannin extracts through extrusion-gelation method was performed comparing two alternative encapsulation matrices: alginate and amidated pectin. The microstructure of the generated microbeads was studied, as well as their microencapsulation efficiency and release properties. Overall, pectin-based beads performed better than their alginate-based counterparts. This, combined with a greater incorporation of tannins in the feed formulations led to a higher tannin load in the final beads. The best microencapsulation efficiency was given by pectin microbeads loaded with 10% tannin extract (w/w), but the final tannin content could be further increased by adding a 20% (w/w) concentration of the extracts. During a 14-days storage, only a marginal loss of tannins was recorded for pectin-based microbeads. The results reveal that great potential exists in producing pectin-based microbeads in presence of tannins, which allow better loading capacities and improving structural properties, thanks to the interactions between the tannins and the amidated polysaccharide.

Evaluation of Tannin-Delivery Approaches for Gut Microbiota Modulation: Comparison of Pectin-Based Microcapsules and Unencapsulated Extracts

“…The concentration of tannins to be added to the feed formulation was established based on the results of preliminary studies. 11 Preparation of the Hydrogel Capsules. All of the pectin solutions were filtered through 0.8 μm pore syringe filters (Sartorius, Germany).…”

“…A 2% (w/v) pectin aqueous solution was prepared by magnetic stirring at room temperature, and increasing concentrations of QUE and CHE with respect to the pectin mass (0 and 20% w/v) were added and mixed until a homogeneous dispersion was obtained. The concentration of tannins to be added to the feed formulation was established based on the results of preliminary studies …”

“…The concentration of tannins to be added to the feed formulation was established based on the results of preliminary studies. 11 …”