Novel high internal phase emulsions (HIPEs, O/W) with gelled oil phase were fabricated via a facile approach using all-natural ingredients. Oil phase of HIPEs was oleogelated with beeswax (BW), and ...the effects of BW concentration (0–6%) on structural properties of the emulsions and stability of β-carotene were highlighted. Microstructural observation indicated that the oil droplets (3–4 μm) of the emulsions were tightly packed with protein bridges at the interfaces and BW crystals inside the droplets. BW crystals were also confirmed by XRD analysis, and the increase in BW concentration led to higher crystallinity in HIPEs. Oleogelation of the oil phase offered the emulsions with improved stability against centrifugation, heating and freeze-thawing, and the HIPE with 3% BW presented the best stability. Small amplitude oscillatory shearing tests revealed that storage modulus of the samples was dependent on BW concentration, and creep-recovery evaluation indicated that the HIPEs with BW had higher resistance over deformation. Large amplitude oscillatory shearing tests showed that the HIPEs with higher content of BW (4.5, 6%) had stain thinning behavior, while those with lower content of BW (0, 1.5, 3%) presented weak strain overshoot characteristics. When β-carotene (up to 2.25%) was incorporated in the oil phase of the emulsions, its stability against light and thermal treatment was significantly improved with the presence of BW, and the emulsion with 3% offered the highest protection. These information suggested that oleogelation of the oil phase facilitated the formation of stable HIPEs and can better behave as carriers for liable bioactives.
Display omitted
•Novel high internal phase emulsions with gelled oil phase were obtained with all natural ingredients.•Oleogelation of the oil phase by beeswax improved emulsion stability.•SAOS and LAOS were applied to characterize the rheology of HIPEs.•β-carotene had higher light and thermal stability in HIPEs.
Pickering emulsions (PEs) offer enhanced stability and reduced toxicity compared to conventional emulsions. Recent advances in polymer chemistry have introduced poly(2-alkyl/aryl-2-oxazoline)s (PAOx) ...as promising alternative emulsifying materials. Known for their biocompatibility, tunability, and stability, PAOx can be rapidly synthesized via microwave-assisted methods. This study explores the use of amphiphilic and non-water-soluble PAOx to stabilize PEs through the formation of polymeric particles (PPs) via nanoprecipitation. Preliminary screening identified HLB5.0 PAOx as effective in forming well-defined PPs. We then investigated the effects of chain length and monomer distribution on the properties of PPs and PEs. Unlike block-based particles, the use of gradient PAOx allowed modulation of the particles’ glass transition temperature while maintaining their size and wettability. In Pickering emulsion formulations, PPs demonstrated effective surface coverage at low concentrations (≈ 0.9 wt%), with DP100-based particles providing enhanced stability and tunable viscosities. The formation of high internal phase PEs further highlights the applicative potential of PAOx, offering broad application prospects in various industries, including biomedicine, pharmaceuticals, and cosmetics.
Display omitted
Chitin nanofibrils (NCh, ∼10 nm lateral size) were produced under conditions that were less severe compared to those for other biomass-derived nanomaterials and used to formulate high internal phase ...Pickering emulsions (HIPPEs). Pre-emulsification followed by continuous oil feeding facilitated a “scaffold” with high elasticity, which arrested droplet mobility and coarsening, achieving edible oil-in-water emulsions with internal phase volume fraction as high as 88%. The high stabilization ability of rodlike NCh originated from the restricted coarsening, droplet breakage and coalescence upon emulsion formation. This was the result of (a) irreversible adsorption at the interface (wettability measurements by the captive bubble method) and (b) structuring in highly interconnected fibrillar networks in the continuous phase (rheology, cryo-SEM, and fluorescent microscopies). Because the surface energy of NCh can be tailored by pH (protonation of surface amino groups), emulsion formation was found to be pH-dependent. Emulsions produced at pH from 3 to 5 were most stable (at least for 3 weeks). Although at a higher pH NCh was dispersible and the three-phase contact angle indicated better interfacial wettability to the oil phase, the lower interdroplet repulsion caused coarsening at high oil loading. We further show the existence of a trade-off between NCh axial aspect and minimum NCh concentration to stabilize 88% oil-in-water HIPPEs: only 0.038 wt % (based on emulsion mass) NCh of high axial aspect was required compared to 0.064 wt % for the shorter one. The as-produced HIPPEs were easily textured by taking advantage of their elastic behavior and resilience to compositional changes. Hence, chitin-based HIPPEs were demonstrated as emulgel inks suitable for 3D printing (millimeter definition) via direct ink writing, e.g., for edible functional foods and ultralight solid foams displaying highly interconnected pores and for potential cell culturing applications.
The ability of lactoferrin (LF)/gum arabic (GA) electrostatic complexes to be used as emulsifiers to form and stabilize high internal phase emulsions (HIPEs) was investigated. The effects of ...protein-polysaccharide ratio and pH on interfacial adsorption and emulsifying capacity were investigated. The ability of cationic LF to adsorb to the oil droplet surfaces was enhanced by the addition of anionic GA. The properties of the interfacial LF/GA complexes could be tuned by varying solution pH, as shown by changes in particle size, turbidity, ζ-potential, and atomic force microscopy. The impacts of pH, salt addition, and heating on the microstructure, stability, rheology of the HIPEs systems were investigated. Curcumin was used as a model lipophilic nutraceutical to investigate the potential of the HIPEs to improve the photostability of encapsulated bioactives. The LF/GA complexes stabilized HIPEs showed gel-like structures, good creaming stability, and excellent environmental stability. This study provides a useful approach for designing HIPEs with improved functional performance. For instance, HIPEs may be used in semi-solid foods to improve their textural characteristics or nutritional profiles.
Display omitted
•Stable and Tunable HIPEs were prepared firstly by LF/GA complexes.•LF/GA complexes improved interfacial adsorption and emulsifying capacity.•The novel HIPEs showed a satisfactory environmental stability.•This study provides a promising way to replace PHOs to structure solid-like fats.
A simple approach was developed to formulate polysaccharide-based high internal phase emulsions (HIPEs) using complexes of sugar beet pectin (SBP), tannic acid (TA), and chitosan (CS) to stabilize ...the system. The ability of pectin to stabilize the HIPEs was significantly improved after it formed complexes with TA, which were likely held together by hydrogen bonding. The stability of the HIPEs was further improved by adding CS, which was attributed to the formation of a 3D biopolymer network around and between the oil droplets. The impact of TA concentration, CS concentration, and pH on the oil droplet size, microstructure, and rheology of the HIPEs was investigated. Compared with SBP/TA complexes, the SBP/TA/CS complexes facilitated the formation of stable HIPEs with a gel-like texture and good stability to centrifugation, dilution, thermal treatment, and ultraviolet light. HIPEs prepared from SBP/TA/CS complexes were shown to delay lipid digestion and improve curcumin bioaccessibility. These findings provide a useful approach for designing HIPE-based soft solids from natural ingredients that can be used in foods and other commercial products.
Display omitted
•HIPEs were formed by complexes of sugar beet pectin, tannic acid and chitosan.•Chitosan (CS) significantly improved the stability of the HIPEs.•CS could better delay the photodegradation of curcumin in the HIPEs.•CS enhanced the stability and bioaccessibility of curcumin in vitro digestion.
•Glycated proteins with excellent emulsifying activities were produced.•Structural and functional attributes of proteins were improved after glycation.•HIPEs were developed by optimized ...protein-anionic polysaccharide Maillard conjugates.•SC-AHSG-stabilized HIPE was ultra-stable against various environmental stresses.
This paper reports the production of O/W high internal phase emulsions (HIPEs) using protein-anionic polysaccharide Maillard conjugates. First, Maillard conjugates were prepared from soy protein isolate (SPI) or sodium caseinate (SC) proteins and Alyssum homolocarpum seed gum (AHSG) or kappa-carrageenan (kC) polysaccharides. The conjugation process was confirmed and monitored by UV spectrophotometry, Fourier transform infrared, circular dichroism, fluorescence spectroscopies, and differential scanning calorimetry. Under the optimized reaction conditions, SC-AHSG conjugates exhibited the highest glycation degree and emulsifying properties. Next, HIPEs were made using the optimized conjugates, and their microstructure, droplet size, and physical stability were evaluated. The emulsion stabilized by SC-AHSG conjugate had the lowest mean droplet size (363.07 ± 34.56 nm), orderly-packed oil droplets with monomodal distribution, the highest zeta potential (-27.70 ± 0.70 mV), high storage stability (no creaming or oil-off) and was ultra-stable against environmental stresses. Results of this research are helpful for development of emulsion-based foods with novel functionality.
Display omitted
•Robust porous PDMS were prepared via a HIPE process for the first time.•Polyethoxysiloxane could in-situ grow into silica particles and strengthen the POMs.•The POMs exhibit ...outstanding oil-water separation performance.
Elastic porous organosilica monoliths (POMs) are successfully prepared by water in oil (w/o) high internal phase emulsions (HIPEs) with a novel silica precursor named polyethoxysiloxane (PEOS) as sole stabilizer. The stability of the HIPEs and the mechanical strength of the POMs are investigated as functions of PEOS and crosslinker contents in the oil phase. FESEM reveals that PEOS molecules play a significant role of in-situ growth into silica particles to strengthen the POMs, which enables the successful preparation of elastic POMs. Furthermore, oil-water separation behavior of the POMs is studied. Both the absorbent capacity and speed are considerably superior to the previously reported PDMS sponges.
PDF
