Emulsion-filled hydrogels for food applications: influence of pH on emulsion stability and a coating on microgel protection

Fabrication and characterization of chitosan-pectin emulsion-filled hydrogel prepared by cold-set gelation to improve bioaccessibility of lipophilic bioactive compounds

Chitosan-pectin emulsion-filled hydrogel (EFH) was developed to enhance the bioaccessibility of lipophilic bioactive compounds through intestinal delivery. The EFH, incorporating a sodium caseinate-stabilized emulsion, was prepared using cold-set gelation under acidic conditions without crosslinking agents. Increasing the pectin concentration (0.75-1.50%, w/v) improved the mechanical strength and compactness of the EFH. The pH-responsive EFH retained the emulsion at pH 2.0 and released it at pH 7.4. In vitro digestion demonstrated that the EFH remained intact during oral and gastric stages, while the emulsion alone became destabilized. During intestinal digestion, the release of free fatty acids from the EFH decreased from 58.67% to 43.76% as the pectin concentration increased from 0.75% to 1.50%. EFH with 0.75% and 1.00% pectin significantly improved curcumin bioaccessibility compared to the emulsion alone. These findings demonstrate the potential of chitosan-pectin EFH as a novel carrier system for enhancing the bioaccessibility of lipophilic bioactive compounds.

Wheat bran arabinoxylan-soybean protein isolate emulsion-filled gels as a β-carotene delivery carrier: Effect of polysaccharide content on textural and rheological properties

This study aimed to investigate the effects of different wheat bran arabinoxylan (WBAX) concentrations (1, 2, 3, and 4 wt%) on the structural and physicochemical properties of WBAX-soybean protein isolate (SPI) emulsion-filled gels (EFGs) prepared using laccase and heat treatment. The properties of the various gels as well as their microstructure, rheology, and in vitro digestion behaviors were investigated. Results showed that WBAX-SPI EFGs with a 3 wt% WBAX concentration had a smooth and uniform appearance, high water holding capacity (98.5 ± 0.2 %), and enhanced mechanical properties. Rheological experiments suggested that a stronger and closer gel network was formed at 3 wt% WBAX concentration. Fourier transform infrared spectroscopy showed that laccase and heat treatment not only catalyzed the intramolecular crosslinking of WBAX and SPI, respectively, but also promoted the interaction between WBAX and SPI. Confocal laser scanning microscopy revealed that the WBAX gel network was interspersed within the SPI network. The interactions contributing to the gelation analysis revealed that chemical (disulfide bond) and physical (hydrogen bond and hydrophobic) interactions promoted the formation of denser EFGs. Furthermore, the WBAX-SPI EFGs provided a β-carotene bioaccessibility of 21.8 ± 0.6 %. Therefore, our study suggests that WBAX-SPI EFGs hold promising potential for industrial applications in the delivery of β-carotene.

Control of eriocitrin release from pH-sensitive gelatin-based microgels to inhibit α-glucosidase: an experimental and computational study

α-Glucosidase is among the intestinal epithelial enzymes that produce absorbable glucose in the final stage of glycan catabolism. It leads to an increase in blood glucose levels as a result of high glucose uptake in diabetic patients. However, inhibition of this essential biochemical process can be a useful therapeutic approach to diabetes mellitus (DM). Eriocitrin (ER) is an abundant "flavanone glycoside" in citrus fruits with rich antioxidant properties whose effects on α-Glu inhibition in the small intestine remain to be determined. Herein, pH-sensitive microgels (MGs) were designed based on cross-linked methacrylate with acrylamide (AM) and acrylic acid (AAc) (molar ratio 70 : 30 of AAc : AM) as a controlled release system for sustained delivery of ER into the small intestine. The presence of amide and acrylate in MGs and the mechanical resistance were determined using FT-IR spectroscopy, rheology, and viscoelastometry. In vitro experiments showed that MGs could protect ER against diffusion in the gastric location and adjust its release in the intestinal milieu. The intestinal α-Glu activity was inhibited by ER (IC₅₀ value of 12.50 ± 0.73 μM) in an uncompetitive dose-dependent manner. The presence of ER altered the structure of α-Glu and reduced the hydrophobic pockets of the enzyme. Molecular docking analysis along with molecular dynamics simulation displayed that ER-α-Glu formation is directed by hydrogen binding with Asp69, Asp215, Glu411, Asp307, and Tyr347 residues. Moreover, in vivo assessment showed that rat blood glucose concentration decreased after ER administration compared with the control group. The results highlight that ER-loaded-MGs can be considered as a useful releasing strategy in treating DM via α-Glu inhibition.

A review of nanostructured delivery systems for the encapsulation, protection, and delivery of silymarin: An emerging nutraceutical

Silymarin exhibits biological activities that may promote human health and wellbeing, including antioxidant, antimicrobial, anti-inflammatory, and anti-cancer activities. Consequently, it has potential for application as a nutraceutical ingredient in functional foods and supplements. But its application for this purpose is currently limited by its poor water solubility, chemical stability, and bioavailability. The potential of nano-delivery systems to improve the functional performance of silymarin was reviewed in this manuscript. The formation, attributes, and applications of biopolymer-based, lipid-based, surfactant-based, and miscellaneous nanocarriers are discussed. In particular, the impact of the different delivery systems such as biopolymer-based, lipid-based delivery systems on the gastrointestinal fate of silymarin is summarized. The encapsulation in edible nanocarriers can improve the bioavailability of silymarin by enhancing its water-dispersibility, inhibiting its degradation, and increasing its absorption.These nanocarriers may therefore be utilized to incorporate this nutraceutical into functional foods and supplements in a bioavailable form.