Ethyl cellulose-chitosan complex particles stabilized W/O Pickering emulsion as a recyclable bio-catalytic microreactor

The dispersibility of biphasic stabilized oil-in-water emulsions improved by the interaction between curdlan and soy protein isolate

Curdlan, a natural polysaccharide, exhibits emulsion-stabilizing and viscosity-modifying properties. However, when employed solely in the aqueous phase, curdlan's adhesive nature impedes droplet dispersion, resulting in a gel-like structure with limited applicability. This investigation formulated a biphasic stabilized oil-in-water emulsion by supplementing the oil phase with beeswax and the aqueous phase with curdlan and soy protein isolate (SPI). The addition of SPI transformed the structural characteristics from a gel-like to a mayonnaise-like structure. Maximal electrostatic repulsion was observed at an internal phase volume fraction of 30%, effectively precluding droplet aggregation owing to the absolute zeta potentials surpassing 40 mV. The emulsions displayed shear-thinning rheological behavior, with a higher storage modulus than the loss modulus, indicative of favorable elastic properties. Molecular docking revealed the predominant role of polar amino acids in facilitating hydrogen bond formation. This study provides a template for developing emulsions with biphasic stability and desirable dispersibility.

Pickering emulsion biocatalysis: Bridging interfacial design with enzymatic reactions

Non-homogeneous enzyme-catalyzed systems are more widely used than homogeneous systems. Distinguished from the conventional biphasic approach, Pickering emulsion stabilized by ultrafine solid particles opens up an innovative platform for biocatalysis. Their vast specific surface area significantly enhances enzyme-substrate interactions, dramatically increasing catalytic efficiency. This review comprehensively explores various aspects of Pickering emulsion biocatalysis, provides insights into the multiple types and mechanisms of its catalysis, and offers strategies for material design, enzyme immobilization, emulsion formation control, and reactor design. Characterization methods are summarized for the determination of drop size, emulsion type, interface morphology, and emulsion potential. Furthermore, recent reports on the design of stimuli-responsive reaction systems are reviewed, enabling the simple control of demulsification. Moreover, the review explores applications of Pickering emulsion in single-step, cascade, and continuous flow reactions and outlines the challenges and future directions for the field. Overall, we provide a review focusing on Pickering emulsions catalysis, which can draw the attention of researchers in the field of catalytic system design, further empowering next-generation bioprocessing.

One-Step Generation of O/W/O Double Pickering Emulsions Utilizing Biocompatible Gliadin/Ethyl Cellulose Complex Particles as the Exclusive Stabilizer

Double emulsions hold great potential for various applications due to their compartmentalized internal structures. However, achieving their long-term physical stability remains a challenging task. Here, we present a simple one-step method for producing stable oil-in-water-in-oil (O/W/O) double emulsions using biocompatible gliadin/ethyl cellulose complex particles as the sole stabilizer. The resulting O/W/O systems serve as effective platforms for encapsulating enzymes and as templates for synthesizing porous microspheres. We investigated the impact of particle concentration and water fraction on the properties of Pickering O/W/O emulsions. Our results demonstrate that the number and volume of inner oil droplets increased proportionally with both the water fraction and particle concentration after a 60-day storage period. Moreover, the catalytic reaction rate of the encapsulated lipase within the double emulsion exhibited a significant acceleration, achieving a substrate conversion of 80.9% within 15 min. Remarkably, the encapsulated enzyme showed excellent recyclability, enabling up to 10 cycles of reuse. Additionally, by utilizing the O/W/O systems as templates, we successfully obtained porous microspheres whose size can be controlled by the outer water droplet. These findings have significant implications for the future design of Pickering complex emulsion-based systems, opening avenues for extensive applications in pharmaceuticals, food, cosmetics, material synthesis, and (bio)catalysis.

Preparation of asymmetric Janus hollow silica microparticle and its application on oily wastewaters

Janus nanoparticles have aroused the interest of scholars because of their highly efficient emulsification of spilled oils in wastewater. In this work, interfacially active Janus hollow glass microparticles (J-HGMPs) of asymmetric wettability were designed and synthesized in order to achieve more efficient separation of emulsified oil droplets from oily wastewater. Surface characteristic techniques such as FTIR, SEM, zeta potential and contact angle measurements had been employed to assess the amphiphilic surface properties of J-HGMPs. The oil removal/recovery performance of J-HGMPs in different oil-water systems and their interfacial activities were studied. As a particulate emulsifier, J-HGMPs could remove/recover > 96% oil from oil-water mixed phase. The results showed that J-HGMPs had strong interfacial activities and anchored firmly at oil/water interfaces. This high adsorption energy was also evaluated and verified via the calculation of Gibbs free energy. Overall, this study provided a novel and low-cost oil recovery method via a convenient buoyancy force that could be effectively applied in the treatment of oil spills while achieving the goal of benign and green environmental protection.

Ultrasonic Treatment of Food Colloidal Systems Containing Oleogels: A Review

The use of oleogels as an alternative to solid fats to reduce the content of saturated and trans-isomeric fatty acids is a developing area of research. Studies devoted to the search for methods of obtaining oleogels with given properties are of current interest. Ultrasonic treatment as a method for modifying oleogel properties has been used to solve this problem. The number of publications on the study of the effect of ultrasonic treatment on oleogel properties is increasing. This review aimed to systematize and summarize existing data. It allowed us to identify the incompleteness of this data, assess the effect of ultrasonic treatment on oleogel properties, which depends on various factors, and identify the vector of this direction in the food industry. A more detailed description of the parameters of ultrasonic treatment is needed to compare the results between various publications. Ultrasonic treatment generally leads to a decrease in crystal size and an increase in oil-binding capacity, rheological properties, and hardness. The chemical composition of oleogels and the concentration of gelators, the amplitude and duration of sonication, the cooling rate, and the crystallization process stage at which the treatment occurs are shown to be the factors influencing the efficiency of the ultrasonic treatment.

Improving the gastrointestinal activity of probiotics through encapsulation within biphasic gel water-in-oil emulsions

The development of probiotics encapsulation strategies has always been a hot topic due to the high sensitivity of probiotics to processing, storage and the gastrointestinal environment. In this study, water in oil (W/O) emulsions of single-phase or dual-phase gels were constructed through the water phase, oil phase alone or all gels. And the W/O emulsions were used to encapsulate Bifidobacterium lactis V9. The effects of water, oil and biphasic gels on the physicochemical properties of the emulsion and the probiotic activity were investigated. Water, oil and biphasic gels contribute to the stability of emulsions. Oil-phase gels make the emulsion form a solid-like texture, while water-phase gels have no significant effect on the liquidity of the emulsion. The microscopic image shows that the probiotics were completely encapsulated in the internal aqueous phase due to the excellent water affinity of probiotic powder. In addition, all W/O emulsions retain higher probiotic activity, which is attributed to good physical isolation during the gastric phase, while oil-phase and biphasic gel emulsions have high probiotic activity after intestinal digestion due to reduced lipid digestion by oil-phase gels. A liquid or solid-state encapsulated probiotic emulsion has been developed and can be used as a coating sauce, solid fat, etc., which can provide additional ideas for probiotic encapsulation systems and functional food development.