Preparation of pickering emulsion stabilised by Zein/Grape seed proanthocyanidins binary composite

Effects of myricetin and its derivatives on nonenzymatic glycation: A mechanism study based on proteomic modification and fluorescence spectroscopy analysis

Myricetin and its derivatives, myricitrin and dihydromyricetin, are flavonoids widely presented in foods and phytomedicine that possess tremendous health potential. In this study, we compared the antiglycation activity of myricetin and its derivatives, then investigated the underlying mechanism using proteomic modification and fluorescence spectroscopy analysis. All three compounds exhibited thorough inhibition on nonenzymatic glycation process, with the inhibitory effects on AGEs reaching 85% at 40 μmol/L. They effectively protected bovine serum albumin (BSA) structure by inhibiting protein oxidation, preventing the conversion from α-helix to β-sheet, and reducing amyloid-like cross-β structure formation. Among the three compounds, myricetin showed a predominant antiglycation activity. Proteomic analysis identified the early glycated sites that were protected by myricetin, including lysine K235, 256, 336, 421, 420, 489, etc. Additionally, fluorescence spectroscopy revealed spontaneous interactions between BSA and myricetin. Overall, myricetin holds promise as an antiglycation agent in both the food and drug industries.

Pickering emulsion stabilized by quercetin-β-cyclodextrin-diglyceride particles: Effect of diglyceride content on interfacial behavior and emulsifying property of complex particles

This research develops diacylglycerol (DAG) based Pickering emulsions with enhanced oxidative stability stabilized by self-assembled quercetin/DAG/β-cyclodextrin (β-CD) complexes (QDCCs) using a one-step agitation method. Influence of DAG content (5%, 15%, 40%, and 80%, w/w) on the self-assembly behavior, interfacial properties, and emulsifying ability of complex particles was investigated. SEM, XRD and ATR-FTIR studies confirmed the formation of ternary composite particles. QDCCs in 80% DAG oil had the highest quercetin encapsulation efficiency (6.09 ± 0.01%), highest DPPH radical scavenging rate and ferric reducing antioxidant property (FRAP). β-CD and quercetin adsorption rates in emulsion with 80% DAG oil were 88.4 ± 2.53% and 98.34 ± 0.15%, respectively. Pickering emulsions with 80% DAG had the smallest droplet size (8.90 ± 1.87 μm) and excellent oxidation stability. This research develops a novel approach to regulate the physicochemical stability of DAG-based emulsions by anchoring natural antioxidants at the oil-water interface through a one-pot self-assembly method.

The pro-absorptive effect of glycosylated zein-fatty acid complexes on fucoxanthin via the lipid transporter protein delivery pathway

Growing research confirms that lipid transport proteins play a key role in the trans-intestinal epithelial transport of carotenoids. In this study, to simultaneously improve the digestive stability and intestinal absorption of fucoxanthin (FX), functionalized vectors with a capability of up-regulating the expression of FX-specific lipid transporter proteins was fabricated. The results showed that myristic acid, palmitic acid, and stearic acid effectively promoted FX-specific lipid transporter protein expression and formed stable self-assembly complexes with Millard-modified zein (MZ). The FX was sufficiently encapsulated in the MZ-fatty acid (FA) particles, forming spherical nanoparticles with a "core-shell" structure. Simulated gastrointestinal digestion showed that FA introduction significantly increased the FX bioaccessibility. In vivo results further verified that adding FAs dramatically increased the FX serum response concentration. These findings suggest that incorporating nutrients that can promote lipid transporter protein expression into delivery vehicles should be an effective strategy for improving oral carotenoid absorption.

Fabrication and characterization of a novel zein/pectin/pumpkin seed oil Pickering emulsion and the effects of myricetin on oxidation stability

In this study, zein/pectin/pumpkin seed oil (PSO) Pickering emulsions (ZPPEs) were fabricated loading with myricetin (MYT), and the quality control methods of oxidation stability were innovatively investigated. The microstructure and particle properties of zein-pectin particles were determined. The zein to pectin ratio of 5:3 and oil phase fraction (φ = 50 %) turned out as the most optimal conditions for the stabilization of myricetin-loaded ZPPEs. The expected oil-in-water emulsion-type structure was confirmed by confocal laser scanning microscopy (CLSM). The internal 3D structure of Pickering emulsions (Lugol's solution improved the water-phase contrast) was imaged by micro-computed tomography (Micro-CT) for the first time. Results showed a sponge like structure of water phase in emulsion with 42 μm as mean droplet size. Light-induced oxidation was evaluated with the PetroOxy method and malondialdehyde (MDA) assays. Encapsuling ZPPEs with MYT could prevent the light induced oxidation, especially, loading of MYT at the core of the emulsion. The analysis of Electronic nose (E-nose) was used to analyze the odor before and after UV-induced oxidation, and showed a good discrimination. This study provided a new approach to prepare ZPPEs with high oxidation stability. Micro-CT, PetroOxy and E-nose could be new methods for characterization and quality assessment of Pickering emulsions.

Inhibitory mechanism of carboxymethyl chitosan-lotus seedpod oligomeric procyanidin nanoparticles on dietary advanced glycation end products released from glycated casein during digestion

Lotus seedpod oligomeric procyanidins (LSOPC) are potent inhibitors of advanced glycation end products (AGEs), whose gastrointestinal susceptibility to degradation limits their use in vivo. In this study, carboxymethyl chitosan-lotus seedpod oligomeric procyanidin nanoparticles (CMC-LSOPC NPs) were constructed with a binding ratio of 1:6.51. CMC-LSOPC NPs significantly inhibited the release of AGEs from glycated casein (G-CS) during digestion, increasing the inhibition rate by 25.76% in the gastric phase and by 14.33% in the intestinal phase compared with LSOPC alone. To further investigate the inhibition mechanism, fluorescence microscopy, scanning electron microscopy and FTIR were used to find that CMC-LSOPC NPs could form cohesions to encapsulate G-CS in the gastric phase and hinder G-CS hydrolysis. In the intestinal phase, LSOPC was targeted for release and bound to trypsin through hydrophobic interactions and hydrogen bonding, resulting in protein peptide chain rearrangement, changes in secondary structure and significant reduction in trypsin activity. In addition, CMC-LSOPC NPs increased the antioxidant capacity of digestive fluid and could reduce the oxidative stress in the gastrointestinal tract caused by the release of AGEs. It's the first time that CMC-LSOPC NPs were constructed to enhance the stability of LSOPC during digestion and explain the mechanism by which CMC-LSOPC NPs inhibit the release of AGEs from G-CS in both stomach and intestine. This finding will present a novel approach for reducing AGEs during gastrointestinal digestion.

Hydroxypropyl methyl cellulose/soybean protein isolate nanoparticles incorporated broccoli leaf polyphenol to effectively improve the stability of Pickering emulsions

This study prepared SPI-Pol-HPMC (SPH) nanoparticles from soybean protein isolate (SPI), hydroxypropyl methyl cellulose (HPMC), and broccoli leaf polyphenol (Pol) and used them as a stabilizer for the Pickering emulsion. The SPH (2:1) nanoparticles have the best ability to encapsulate broccoli leaf polyphenols, with uniform particle size distribution, and a more dense and stable structure. The chemical and hydrogen bonding forces between the SPH nanoparticle components were enhanced. Additionally, the 1.5 % SPH nanoparticle-stabilized emulsions exhibited good physical stability, manifesting as small particle droplets with good rheological properties and uniform dispersion. The volume fraction of the emulsified phase of the 1.5 % SPH nanoparticle-stabilized emulsions was the greatest after 21 days of storage. Interestingly, SPH nanoparticles also improved the oxidative stability of the emulsions, as evidenced through their lower peroxide values and thiobarbituric acid active substances. The aforementioned results suggest that SPH nanoparticles may be used as food-grade emulsifiers that stabilize emulsions and inhibit their lipid oxidation.

Formation mechanism of Pickering emulsion gels stabilized by proanthocyanidin particles: Experimental and molecular dynamics studies

The feasibility of constructing a Pickering emulsion gel with proanthocyanidin particles (PAP) was evaluated in this study, and the related mechanism was revealed by combining instrumental characterization with molecular dynamics simulation. The results showed that PAP was composed of nano/micron spherical particles or their fragments, which had excellent wettability. Suitable PAP addition amount (w, ≥1%) and oil volume fraction (φ, 40-90 %) were beneficial to the formation of stable Pickering emulsion gel. The oil droplet size of gel was inversely proportional to w and φ. The mechanical parameters (gel strength, loss modulus, and storage modulus) were positively correlated with w and φ. Molecular dynamics simulation indicated that the proanthocyanidin molecules in the oil-water system could spontaneously reside and aggregate at the interface, and their interactions with water and oil reduced interfacial tension, which was consistent with the experimental results. This study provides a reference for other polyphenol-based Pickering emulsions.

The Potential Application of Pickering Multiple Emulsions in Food

Emulsions stabilized by adsorbed particles—Pickering particles (PPs) instead of surfactants and emulsifiers are called Pickering emulsions. Here, we review the possible uses of Pickering multiple emulsions (PMEs) in the food industry. Food-grade PMEs are very complex systems with high potential for application in food technology. They can be prepared by traditional two-step emulsification processes but also using complex techniques, e.g., microfluidic devices. Compared to those stabilized with an emulsifier, PMEs provide more benefits such as lower susceptibility to coalescence, possible encapsulation of functional compounds in PMEs or even PPs with controlled release, etc. Additionally, the PPs can be made from food-grade by-products. Naturally, w/o/w emulsions in the Pickering form can also provide benefits such as fat reduction by partial replacement of fat phase with internal water phase and encapsulation of sensitive compounds in the internal water phase. A possible advanced type of PMEs may be stabilized by Janus particles, which can change their physicochemical properties and control properties of the whole emulsion systems. These emulsions have big potential as biosensors. In this paper, recent advances in the application of PPs in food emulsions are highlighted with emphasis on the potential application in food-grade PMEs.