Octenylsuccinated alginate as a delivery agent for encapsulation of bergamot essential oil: Preparation, functional properties and release behavior

Abstract

This study evaluate the effect of succinylation of sodium alginate (ALG) by octenyl succinic anhydride (OSA) and its effect on the bergamot essential oil (BEO)-loaded ALG beads. The physico-chemical, antioxidant, antibacterial, and in vitro release properties of BEO-loaded ALG beads were assessed. The presence of BEO in alginate beads was assessd using Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC) experiments. The higher amount of BEO in modified alginate beads at higher degree of substitution (DS) has been confirmed. Accordingly, it was discovered that the DS has notable effects on encapsulation efficiency (EE), loading capacity (LC) of beads, so that the values of EE and LC were about 31–75 % and 19–45 %, respectively, when the DS value of ALG was 0.00–0.022. Besides, BEO-loaded beads prepared using high DS, exhibited higher total phenolic compound (TPC = 21.101 mg garlic acid/g brad), good antioxidant activity (DPPH radical scavenging activity ≈ 69 %) and antibacterial properties (against E. coli and S. aureus). In vitro release analysis showed the initial fast release followed by a slow-release. OSA modification slowed down the release rate of bergamot essential oil from alginate beads. Also, the release of BEO from the beads followed Fickian diffusion.