Preparation and Self-Assembly Mechanism of Bovine Serum Albumin-Citrus Peel Pectin Conjugated Hydrogel: A Potential Delivery System for Vitamin C

In this study, a novel hydrogel (BSA pectin hydrogel, BPH) was prepared via a self-assembly method by using the natural polymers of bovine serum albumin (BSA) and citrus peel pectin (pectin). The rheological properties and gel conformational structures were determined and showed that electrostatic and covalent interactions between BSA and pectin were the main mechanisms for the formation of BPH. The morphological characteristics of BPH included a stable and solid three-dimensional network structure with a narrow size distribution (polydispersity index <0.06). BPH was used as a delivery system to load the functional agent vitamin C (Vc). The encapsulation efficiency (BE) and release properties of Vc from BPH were also investigated. The results revealed that the EE of Vc into BPH was approximately 65.31%, and the in vitro Vc release from BPH was governed by two distinct stages (i.e., burst release and sustained release) in different pH solutions, with release mechanisms involving diffusion, swelling, and erosion. Meanwhile, the stability results showed that BPH was a stable system with an enhanced Vc retention (73.95%) after 10 weeks of storage. Thus, this three-dimensional network system of BPH may be a potential delivery system to improve the stability and bioavailability of functional agents in both food and non-food fields.