Fabrication of Novel Hierarchical Multicompartment Highly Stable Triple Emulsions for the Segregation and Protection of Multiple Cargos by Spatial Co-encapsulation

Advances of emulsification during the lifetime development of heavy oil reservoirs

Emulsifications are associated with the reservoir formation and lifetime development due to the characteristics of heavy oil and influence of injected fluid. The types of formed emulsions (W/O, O/W, or W/O/W) are also change as time goes. Therefore, based on the characteristics and development methods of heavy oil reservoir, emulsifications and their properties during lifetime development are summarized in detail. Heavy oil reservoirs are usually developed by water injection/steam, followed by chemical agents flooding. Tremendous stable W/O emulsions would be formed during water/steam injection due to the action of active components in heavy oil. Resulting in significant changes of viscosity, freezing point, interface characteristics and yield characteristics. Therefore, the efficient development may severely restricted. Chemical agents can emulsify heavy oil to form O/W emulsion and greatly improve the fluidity. Its formation, stability, and interface characteristics are all affected by properties, types and adsorption forms of chemical agents on interface. Researchers are also committed to the study of interface characteristics and stability mechanism, to solve the problem of efficient development of heavy oil. However, serious W/O emulsion has occurred before chemical injection. In fact, the more common type of emulsion formed is W/O/W emulsion. Its properties are also very different from O/W emulsions due to the complexity of composition and structure. The study of W/O/W emulsion formation, stability and flow behavior is more suitable for chemical flooding. Similarly, the development and evaluation of chemical agents should focus more in its emulsification on W/O emulsion in porous media. The results obtained can provide the basic theory for study of interface characteristics and micro-dynamics of heavy oil-water-chemical agent during the lifetime development of heavy oil reservoir.

Comparative analysis of physicochemical properties and functionalities of artificial oil bodies stabilized by different seed oil body proteins

In this study, ‌perilla seed oil body protein (PO), hempseed oil body protein (HO), and cucumber seed oil body protein (CO) were utilized to prepare artificial oil bodies (AOBs), and the impact of protein type on their physicochemical properties was investigated.‌ ‌Compared to HO and CO, PO exhibited a lower zeta potential value of -48.27 mV, a higher surface hydrophobicity of 21,122.67, and a smaller particle size of 105.71 nm. Its emulsifying activity index (EAI) and emulsion stability index (ESI) were 83.06 m2/g and 167.9 %, respectively. ‌Furthermore, AOBs stabilized by PO demonstrated smaller particle size and a higher amount of interfacial adsorbed protein compared to those prepared by HO and CO.‌ ‌Additionally, the encapsulation results indicated that PO-AOBs exhibited a higher encapsulation efficiency of 98.34 %. The retention rates of the loaded curcumin were 56.94 % after exposure to 90 °C and 94.06 % after UV light exposure for 7 h. ‌Moreover, both digestion and antioxidant experiments indicated that PO-AOBs facilitated better release of curcumin in the intestine, leading to enhanced antioxidant properties and increased bioavailability.‌ These findings offer ‌new insights into the development of novel AOBs, which hold promise for diverse applications in food delivery systems.

Investigation on the structure characteristics, stability evaluation, and oral tribology of natural oleanolic acid-based water-in-oil high internal phase and multiple Pickering emulsions as realistic fat analogues

Herein, it proved that oleanolic acid (OA) could self-assemble into particles in oil, further exhibiting great potential in creating Pickering water-in-oil (W/O) high internal phase emulsions (HIPEs) with desirable fat-like attributes. W/O HIPE with a water content of 85 wt% could be stabilized by 3 wt% OA, their fat-like performance could be optimized by modulating the filling density of water droplets and interfacial coverage. The stabilization included particle-coated, particle and droplet co-coated, and droplet-coated interfaces depending on the OA amount. HIPEs with excellent tolerance to high-temperature and freeze-thaw treatment could be achieved. Moreover, dual-interface Pickering-stabilization water-in-oil-in-water (W/O/W) emulsions with a fat-like texture were fabricated via a one-step homogenization stabilized with OA particles and microgels. Importantly, OA-based W/O and W/O/W emulsion gels possessed smooth oral sensation and similar tribology behaviors to milk fat. This work is expected to provide a "clean-label" route to develop multiphase fat analogues involved in natural materials.

The potential of curcumin-based co-delivery systems for applications in the food industry: Food preservation, freshness monitoring, and functional food

Currently, curcumin-based co-delivery systems are receiving widespread attention. However, a systematic summary of the possibility of curcumin-based co-delivery systems used for the food industry from multiple directions based on the functional characteristics of curcumin is lacking. This review details the different forms of curcumin-based co-delivery systems including the single system of nanoparticle, liposome, double emulsion, and multiple systems composed of different hydrocolloids. The structural composition, stability, encapsulation efficiency, and protective effects of these forms are discussed comprehensively. The functional characteristics of curcumin-based co-delivery systems are summarized, involving biological activity (antimicrobial and antioxidant), pH-responsive discoloration, and bioaccessibility/bioavailability. Correspondingly, potential applications for food preservation, freshness detection, and functional foods are introduced. In the future, more novel co-delivery systems for active ingredients and food matrices should be developed. Besides, the synergistic mechanisms between active ingredients, delivery carrier/active ingredient, and external physical condition/active ingredient should be explored. In conclusion, curcumin-based co-delivery systems have the potential to be widely used in the food industry.

Edible HIPE-Gels and oleogels formed by synergistically combining natural triterpenoid saponin and citrus dietary fiber

High-internal-phase emulsion gels (HIPE-Gels) and oleogels were successfully fabricated through synergistically combination of natural triterpenoid Quillaja saponin (QS) and citrus dietary fiber (CDF). The amphiphilic QS significantly lowered the oil-water interface tension; whereas CDF could form compact structure at the interface as well as in the bulk under a hydrogen-bonding interaction with saponin. The combination endowed the emulsion gels with enhanced performance, such as decreasing droplet size, strengthening gel network structure and better viscoelastic. At a very low QS of 0.045 %, stable HIPE-Gels can be produced with 0.3 % CDF, which mainly attributing to the highly viscoelastic fiber networks in continuous phase and thus actively trap the QS-coated emulsion droplets. Consequently, the robust HIPE-Gels were applied as soft template to fabricate oleogels with controlled by QS and CDF loading. These findings proved an effective strategy towards structuring edible liquid oil into healthy gels for alternating saturated and trans fats in foods.

Characterization of bacterial cellulose nanofibers/soy protein isolate complex particles for Pickering emulsion gels: The effect of protein structure changes induced by pH

In this work, the influence of soy protein isolated at different pH values (1-9) on the self-assembly behaviors of bacterial cellulose nanofibers/soy protein isolate (BCNs/SPI) colloidal particles via anti-solvent precipitation were investigated. The results showed that the formation of BCNs/SPI at pH values of 1-5 was mainly driven by electrostatic interaction, while the formation of those at pH values of 5-9 was driven by weak molecular interactions including hydrogen bonding and steric-hindrance effect. The FTIR demonstrated that the conformation of protein involved a transition from order to disorder at the level of secondary structure as pH values were away from the isoelectric point. The fluorescence spectroscopy and UV-vis adsorption spectroscopy indicated that hydrophobic region of SPI at pH value of 5 displayed more exposed as compared with that at pH values away from the isoelectric point. The changes in structure conformation of SPI induced by pH values led to the changes in properties of the BCNs/SPI colloidal particles including particle size, microstructure, crystallinity, hydrophily, thermal stability, and rheological properties. Furthermore, the structures of BCNs/SPI colloidal particles at different pH values significantly affected the stability of Pickering emulsion gels stabilized by the corresponding complex colloidal particles. This study provided a theoretical basis for the design of food-grade Pickering emulsion gels stabilized by BCNs/SPI complex colloidal particles.

Updated design strategies for oral delivery systems: maximized bioefficacy of dietary bioactive compounds achieved by inducing proper digestive fate and sensory attributes

Interest in the application of dietary bioactive compounds (DBC) in healthcare and pharmaceutical industries has motivated researchers to develop functional delivery systems (FDS) aiming to maximize their bioefficacy. As the direct and indirect health benefiting effects of DBC are acknowledged, traditional design principle of FDS aiming at improving the bioavailability of intact DBC is challenged by the updated one, where the maximized bioefficacy of DBC delivered by FDS will be achieved via rationally absorbed at target sites with proper metabolism pathways. This article briefly summarized the absorption and metabolic fates of orally digested DBC along with their direct and indirect mechanisms to perform health benefiting effects. Current strategies in designing the next generation FDS with an emphasis on their modulation effects on the distribution portion between the upper and lower digestive tract, portal vein and lymphatic absorption, human digestive and gut microbiota enzymatic mediated metabolism were highlighted. Updated research progresses of FDS in adjusting sensory attributes of food end products and inducing synergistic effects rooting from matrix materials and co-delivered cargos were also discussed. Challenges as well as future perspectives concerning the precise nutrition and the critical role of delivery systems in dietary intervention were proposed.

Investigation of the Formation Mechanism and Curcumin Bioaccessibility of Emulsion Gels Based on Sugar Beet Pectin and Laccase Catalysis

In this study, modified whey protein hydrolysates (WPH) were obtained after succinic anhydride succinylation and linear dextrin glycation, and emulsion gels were prepared on the basis of unmodified/modified WPH stabilized emulsions with sugar beet pectin (SBP) addition and laccase-catalyzed cross-linking. The influences of emulsifier types and SBP contents on the texture of emulsion gels were estimated. The texture and rheological properties of emulsion gels were characterized. An ideal gel emulsion was formed when the SBP content was 3% (w/w). A uniform network was observed in emulsion gels stabilized by W-L, W-L-S, and W-S-L. In addition, the effect of the emulsifier type on the bioaccessibility of curcumin encapsulated in emulsion gels was investigated and the W-S-L stabilized emulsion gel exhibited the highest curcumin bioaccessibility (65.57%). This study provides a theoretical basis for the development of emulsion gels with different textures by SBP addition and laccase cross-linking as encapsulation delivery systems.

Oil-Water Interfacial-Directed Spontaneous Self-Assembly of Natural Quillaja Saponin for Controlling Interface Permeability in Colloidal Emulsions

Assembly of amphiphiles at the interface of two immiscible fluids is of great scientific and technological interest in offering efficient routes to smart vehicles for functional deliveries. Natural Quillaja saponin (QS) has gathered widespread interest within the scientific community as a result of its unique interfacial properties. Herein, spontaneously interface-driven self-assembly (SIDSA) of QS at the oil-water interface was systematically studied by morphology and spectroscopy. It was found to self-assemble into a micrometer-scale network in helical fibers by combined intermolecular π-π stacking and hydrogen bonding among saponins at the liquid-liquid interface. From SIDSA, multilayer films on the surfaces of dispersed droplets were formed and enhanced emulsion stability. Interfacial QS-based films on droplet surfaces were also shown to confine interfacial diffusion processes by serving as transport barriers. Furthermore, they can be exploited to control the release of volatiles from the dispersed liquid phase by regulating the interface film, which is shown by molecular dynamics to occur through a hydrogen-bonded mechanism. These results provide new insight into the interfacial assembly structure that can enable unique controllable release in a broad range of applications in food, beverages, pharmaceuticals, and cosmetics.

Independent co-delivery of model actives with different degrees of hydrophilicity from oil-in-water and water-in-oil emulsions stabilised by solid lipid particles via a Pickering mechanism: a-proof-of-principle study

HYPOTHESIS

The development of vehicles for the co-encapsulation of actives with diverse characteristics and their subsequent controllable co-delivery is gaining increasing research interest. Predominantly centred around pharmaceutical applications, the majority of such co-delivery approaches have been focusing on solid formulations and less so on liquid-based systems. Simple emulsions can be designed to offer a liquid-based microstructural platform for the compartmentalised multi-delivery of actives.

EXPERIMENTS

In this work, solid lipid nanoparticle stabilised Pickering emulsions were used for the co-encapsulation/co-delivery of two model actives with different degrees of hydrophilicity. Lipid particles containing a model hydrophobic active were prepared in the presence of either Tween 20 or whey protein isolate, and were then used to stabilise water-in-oil or oil-in-water emulsions, containing a secondary model active within their dispersed phase.

FINDINGS

Solid lipid nanoparticles prepared with either type of emulsifier were able to provide stable emulsions. Release kinetic data fitting revealed that different co-delivery profiles can be achieved by controlling the surface properties of the lipid nanoparticles. The current proof-of-principle study presents preliminary data that confirm the potential of this approach to be utilised as a flexible liquid-based platform for the segregated co-encapsulation and independent co-release of different combinations of actives, either hydrophobic/hydrophilic or hydrophobic/hydrophobic, with diverse release profiles.