Tailoring the physicochemical stability and delivery properties of emulsions stabilized by egg white microgel particles via glycation: Role of interfacial particle network and digestive metabolites

The influence of unique interfacial networks based on egg white proteins for the stabilization of high internal phase Pickering emulsions: Physical stability and free fatty acid release kinetics

This study was oriented towards the impacts of unique interfacial networks, formed by glycosylated and non-glycosylated egg white proteins, on the characteristics of high internal phase Pickering emulsions (HIPPEs). Glycosylated egg white protein particles (EWPG) manifested a more compact protein tertiary structure and amplified surface hydrophobicity, forming durable coral-like networks at the oil-water interface. The non-glycosylated egg white protein particles (EWP) could form spherical cluster interfacial networks. Raman spectroscopy analysis illuminated that EWPG could exhibit better interactions with aliphatic amino acids via hydrogen bonds and hydrophobic interactions. The release of free fatty acid (FFA) from both HIPPEs followed the first-order kinetic model with a combination of diffusion. EWPG-stabilized HIPPEs demonstrated superior physical stability and cellular antioxidant activity. This research shed light on the promising prospects of HIPPEs as promising amphiphilic delivery systems with capabilities to co-deliver hydrophilic and hydrophobic nutraceuticals and amplify their intracellular biological potency.

Oral Synergism of Egg-White-Derived Peptides (EWDP) and Curcumin for Colitis Mitigation via Polysaccharide/Cyclodextrin Metal-Organic Framework-Based Assemblies

Recently, oral deliverable strategies of multiple nutraceuticals for ulcerative colitis (UC) mitigation have attracted increasing attention. This study aimed to fabricate facile oral assemblies loaded with egg-white-derived peptides (EWDP) and curcumin based on carboxymethyl chitosan (CMCS) and an γ-cyclodextrin metal-organic framework (MOF). Herein, outer CMCS could coassemble with EWDP (both nutraceuticals and building blocks) into cobweb-like fibrils to promote bridging with inner MOF via coordinative noncovalent interactions (hydrogen bonding, hydrophobic interaction, and electrostatic interaction). Compared with conventional γ-cyclodextrin/MOF-based composites, the above coassembly could also endow the biocompatible assemblies with superior nanoscale colloidal properties, processing applicability (curcumin storage stability, bioaccessibility, and aqueous solubility), and bioactivity. Moreover, the oral synergism of EWDP and curcumin (initially nonsynergistic) for UC mitigation was achieved by alleviating inflammatory damage and gut microbiota imbalance. Overall, the novel assemblies could be a promising amplifier and platform to facilitate oral formulations of various nutraceuticals for food processing and UC relief.

Effects of κ-carrageenan on the emulsifying ability and encapsulation properties of pea protein isolate-grape seed oil emulsions

This work investigated the characteristics of pea protein isolate and κ-carrageenan complexes in stabilizing curcumin-loaded emulsions. The complexes structured by electrostatic attraction exhibited biphasic wettability with increased three-phase contact angles close to 90°. Morphological differences in the complexes were the critical factor influencing their emulsifying ability at various pH. As a steric barrier via increasing net negative charge (up to -54.7 ± 2.4 mV) and adsorbed protein content (92.57 %-97.61 %), the interfacial layer could retard droplet coalescence and improve emulsions stability. Rheological tests verified the higher viscoelasticity of emulsions by raising the oil fraction. After 4 weeks of heating treatment, the chemical stability of curcumin was prominently enhanced from 18.6 ± 0.2 % to 64.3 ± 5.7 %. The confirmed synergistic antioxidant activity between grape seed oil and curcumin in emulsions might facilitate the development of specific functional delivery systems in foods.

Egg White Protein-Proanthocyanin Complexes Stabilized Emulsions: Investigation of Physical Stability, Digestion Kinetics, and Free Fatty Acid Release Dynamics

Egg white proteins pose notable limitations in emulsion applications due to their inadequate wettability and interfacial instability. Polyphenol-driven alterations in proteins serve as an effective strategy for optimizing their properties. Herein, covalent and non-covalent complexes of egg white proteins-proanthocyanins were synthesized. The analysis of structural alterations, amino acid side chains and wettability was performed. The superior wettability (80.00° ± 2.23°) and rigid structure (2.95 GPa) of covalent complexes established favorable conditions for their utilization in emulsions. Furthermore, stability evaluation, digestion kinetics, free fatty acid (FFA) release kinetics, and correlation analysis were explored to unravel the impact of covalent and non-covalent modification on emulsion stability, dynamic digestion process, and interlinkages. Emulsion stabilized by covalent complex exhibited exceptional stabilization properties, and FFA release kinetics followed both first-order and Korsmeyer-Peppas models. This study offers valuable insights into the application of complexes of proteins-polyphenols in emulsion systems and introduces an innovative approach for analyzing the dynamics of the emulsion digestion process.

Glycation-induced enhancement of yeast cell protein for improved stability and curcumin delivery in Pickering high internal phase emulsions

Pickering high internal phase emulsions (HIPEs) have gained significant attention for various applications within the food industry. Yeast cell protein (YCP), derived from spent brewer's yeast, stands out as a preferred stabilizing agent due to its cost-effectiveness, abundance, and safety profile. However, challenges persist in utilizing YCP, notably its instability under high salt concentration, thermal processing, and proximity to its isoelectric point. This study aimed to enhance YCP's emulsifying properties through glycation with glucose and evaluate its efficacy as a stabilizer for curcumin (CUR)-loaded HIPEs. The results revealed that glycation increased YCP's surface hydrophobicity, exposing hydrophobic groups. This augmentation, along with steric hindrance from grafted glucose molecules, improved emulsifying properties, resulting in a thicker interfacial layer around oil droplets. This fortified interfacial layer, in synergy with steric hindrance, bolstered resistance to pH changes, salt ions, and thermal degradation. Moreover, HIPEs stabilized with glycated YCP exhibited reduced oxidation rates and improved CUR protection. In vitro digestion studies demonstrated enhanced CUR bioaccessibility, attributed to a faster release of fatty acids. This study underscores the efficacy of glycation as a strategic approach to augment the applicability of biomass proteins, exemplified by glycated YCP, in formulating stable and functional HIPEs for diverse food applications.

Development and characterization of emulsion gels prepared via gliadin-based colloidal particles and gellan gum with tunable rheological properties for 3D printed dysphagia diet

Dysphagia, a condition characterized by difficulty swallowing, has emerged as a threat to health. Herein, we investigated the feasibility of preparing a novel 3D-printed dysphagia diet using emulsions and gellan gum. A gel network was facilitated by the inclusion of gellan gum, which also helped to reduce the size of the oil droplets. Emulsion gels (with 0.3 %-0.5 % gellan gum) were stable at 25 °C for 30 days and tolerated a high ionic concentration of 800 mmol L-1. Emulsion gels remained stable after heat treatment and centrifugation. The excellent stability of the emulsion gels was related to the three-dimensional network developed by the gellan gum. The rheological results validated the solid-state behavior, shear thinning behavior and structural recovery of emulsion gels. Emulsion gels with 0.3 %-0.5 % gellan gum were suitable for 3D printing since they had high printing accuracy, self-support, and smooth surface texture. International Diet Standardization Initiative (IDDIS) tests have shown that emulsion gels can be classified as a level 3-5 dysphagia diet. In addition, the bioaccessibility of astaxanthin increased 1.7 times after being encapsulated by emulsion gels. Overall, these results demonstrate the potential of emulsion gels in the development of novel 3D-printed diets for dysphagia and bioactive protection.

Potential Benefits of Egg White Proteins and Their Derived Peptides in the Regulation of the Intestinal Barrier and Gut Microbiota: A Comprehensive Review

Impaired intestinal barrier function can impede the digestion and absorption of nutrients and cause a range of metabolic disorders, which are the main causes of intestinal disease. Evidence suggests that proper dietary protein intake can prevent and alleviate intestinal diseases. Egg white protein (EWP) has received considerable attention, because of its high protein digestibility and rich amino acid composition. Furthermore, bioactive peptides may have an increased repair effect due to their high degradation efficiency in the gut. In this study, we aimed to review the effects of EWP and its bioactive peptides on intestinal structural repair. The potential modulation mechanisms by which EWP and their peptides regulate the gut microbiota and intestinal barrier can be summarized as follows: (1) restoring the structure of the intestinal barrier to its intact form, (2) enhancing the intestinal immune system and alleviating the inflammatory response and oxidative damage, and (3) increasing the relative abundance of beneficial bacteria and metabolites. Further in-depth analysis of the coregulation of multiple signaling pathways by EWP is required, and the combined effects of these multiple mechanisms requires further evaluation in experimental models. Human trials can be considered to understand new directions for development.

Construction and characterization of Pickering emulsions stabilized by soy protein hydrolysate microgel particles and quercetin-loaded performance in vitro digestion

Food-grade Pickering emulsions stabilized by protein microgel particles have received increasing attentions owing to their potential applications in the food industry. Herein, soy protein hydrolysate microgel particles (SPHMs) produced at various pH (3, 5, 7, and 9) with and without ultrasonication were used to stabilize Pickering emulsions. Compared with those prepared using ultrasonication at pH 3-7, SPHMs prepared using ultrasonication at pH 9 showed excellent amphiphility at the oil-water interface and a superior ability to reduce interfacial tension. The Pickering emulsion stabilized by the latter SPHMs displayed a small particle size and a high net charge on the droplet surface, formed a dense honeycomb network interfacial layer with high viscoelasticity and adsorbed protein content, and experienced no visually detectable creaming during storage for 21 days, i.e., exhibited optimum colloidal stability. Furthermore, the above emulsion featured a quercetin encapsulation efficiency of 89.45 % and was capable of sustainable release, achieving a low free fatty acid release efficiency of 61 % and a relatively high quercetin bioaccessibility of 65 % in in vitro simulated digestion experiments. Thus, this work inspires the use of SPHMs in emulsion-based functional foods.

Strategies for modulating the lipid digestion of emulsions in the gastrointestinal tract

The structural changes in emulsion products can be used to control the bioavailability of fatty acids and lipophilic compounds. After ingestion, lipid droplets undergo breakdown and structural changes as they pass through the gastrointestinal tract. The oil-water interface plays a critical role in modulating the digestive behavior of lipid droplets because changes in the interfacial layer control the adsorption of lipase and bile salts and determine the overall rate and extent of lipid digestion. Therefore, lipid digestibility can be tuned by selecting the appropriate types and levels of stabilizers. The stabilizer can change the lipase accessibility and exposure of lipid substrates, resulting in variable digestion rates. However, emulsified lipids are not only added to food matrixes but are also co-ingested from other dietary components. Therefore, overall consumption behaviors can affect the digestion rate and digestibility of emulsified lipids. Although designing an emulsion structure is challenging, controlling lipid digestion can improve the health benefits of products. Therefore, a thorough understanding of the process of emulsified lipid digestion is required to develop food products that enable specific physiological responses. The targeted or delayed release of lipophilic molecules and fatty acids through emulsion systems has significant applications in healthcare and pharmaceuticals.

Spread Layers of Lysozyme Microgel at Liquid Surface

The spread layers of lysozyme (LYS) microgel particles were studied by surface dilational rheology, infrared reflection–absorption spectra, Brewster angle microscopy, atomic force microscopy, and scanning electron microscopy. It is shown that the properties of LYS microgel layers differ significantly from those of ß-lactoglobulin (BLG) microgel layers. In the latter case, the spread protein layer is mainly a monolayer, and the interactions between particles lead to the increase in the dynamic surface elasticity by up to 140 mN/m. In contrast, the dynamic elasticity of the LYS microgel layer does not exceed the values for pure protein layers. The compression isotherms also do not exhibit specific features of the layer collapse that are characteristic for the layers of BLG aggregates. LYS aggregates form trough three-dimensional clusters directly during the spreading process, and protein spherulites do not spread further along the interface. As a result, the liquid surface contains large, almost empty regions and some patches of high local concentration of the microgel particles.