Immobilization of iron-loaded niosomes within electrospun nanofibers of soy protein isolate: A novel dual encapsulation technique

Abstract

In this research, a dual encapsulation system was developed for loading niosomes into electrospun nanofibers of soy protein isolate (SPI)-polyvinyl alcohol (PVA); high hydrostatic pressure (HHP) was also applied to reinforce the nanofibers. For this purpose, different samples with various levels of HHP-treated SPI, PVA, and iron niosomes were prepared. Encapsulation efficiency as well as the bioavailability of iron increased in HHP-treated samples because HHP was able to disassemble the structure of the base polymers (SPI-PVA), allowing the iron to load into the skeleton of the base polymer and, consequently, encapsulated it in the structure strictly and suitably. HHP resulted in a higher transformation and bioavailability of SPI:PVA fibers, which is due to the destruction effect of this pretreatment on SPI and neutralizing its inhibitory effect. HHP eventuated lower Atomic Force Microscopy (AFM) indices in nanofibers because it can cause denaturation and aggregation of proteins, resulting in a more compact and homogeneous protein network. The results of this study are useful as a practical guide on how to prepare niosome-embedded SPI nanofibers (especially for the enrichment of plant-based nanofibers), what their properties are, and how to improve their characteristics through HHP pretreatment.