Search

Probiotics have become increasingly recognized for their potential health-promoting properties; however, the viability of probiotics can be affected by storage and transportation processes as well as the stressful environment of the human digestive tract, preventing them from achieving effective concentration (107 CFU/mL). In this regard, the embedding technology of probiotics provides an effective protection method. Dextran-based water in water (W/W) emulsion loaded with Lactobacillus plantarum was used as spinning solution to prepare Lactobacillus plantarum-loaded electrospun fibers. The structure of the W/W emulsion and the electrospun fibers was charactered. Lactobacillus plantarum were uniformly embedded in the internal phase of the W/W emulsion and the loading efficiency was 9.70 ± 0.40 log CFU/g. After 240 min digestion in the gastrointestinal tract, and temperature treatment in 65 °C and 72 °C, the loaded probiotics maintained high activity. Even after 5 days of storage in room temperature and 4 °C, the loaded probiotic activity levels remained high, with counts >8 log CFU/g. These results suggest that probiotics encapsulated by emulsion electrospinning could be potentially delivered in a novel food delivery system used in the future food industry. [ABSTRACT FROM AUTHOR]

Using non-amphiphilic polysaccharide to stabilize oil-in-water emulsions is still a challenge in food industry. Polysaccharide microgels showed emulsifying capacity, however, the stability of the formed emulsions is far from the requirements of the food industry. In this work, agarose microgel/Tween-20 suspensions were prepared and further employed in oil-in-water emulsion stabilization. Focuses were taken on the impact of Tween-20 on the emulsifying properties of agarose microgels. Results suggested that Tween-20 could complex with agarose microgels, and microamounts of Tween-20 (0.02 wt%) could apparently improve the emulsifying performance of microgels. Dynamic interfacial pressure and interfacial adsorption of microgels indicated that appropriate amount of Tween-20 (≤0.04 wt%) could benefit the interfacial adsorption of agarose microgels, while excessive Tween-20 (≥0.08 wt%) could compete with agarose microgels for adsorption sites on oil/water interface. Results of this work supporting that surfactant complexing could be a promising solution to prepare polysaccharides based Mickering emulsions. [ABSTRACT FROM AUTHOR]

In this research, sodium alginate (ALG) microgels were prepared with different ALG concentrations, and physicochemical and emulsifying profiles of these hydrophilic microgels were comparatively analyzed. Results showed that these microgels possessed different size, hardness, and surface charge. All these microgels could stabilize an oil-in-water emulsion through the Mickering mechanisms, and smaller microgels had better emulsifying capacity. The surface hydrophobicity and interfacial tension of the microgels had no exact effects on their emulsifying behaviors. Compared with the harder microgels (prepared with high ALG concentration, e. g. 4 mg/mL), the emulsifying capacities of the softer ones (prepared with low ALG concentration, e.g. 1 mg/mL) were more sensitive to the high salt concentration (200 mM NaCl) but stable under acidic environment (pH 2.0). Our research would afford a new strategy for the manufacture and application of the novel polysaccharide-based emulsifiers. [ABSTRACT FROM AUTHOR]

This work was focused on the fabrication of a stable O/W Pickering emulsion by using cellulose-rich composites that prepared by selectively oxidation with sodium periodate firstly, and followed by grafting dodecylamine to the 2,3-dialdehyde cellulose particles. The structure and properties of the modified cellulose microparticles were characterized, and the performance for the stabilization of O/W Pickering emulsions was investigated. The surface wettability, rheological behavior of the cellulose microparticles before and after being modified had been compared. The results indicated that the hydrophobically modified cellulose microparticles were more effective in emulsifying oil than that of the pristine cellulose microparticles. The contents of oil and cellulose microparticles used had an influence on the size of emulsion droplets, however, the responsiveness of the emulsions towards pH changed slightly, and oil was not leaked from the droplets at decreased pH. This could be explained by the amphiphilicity of the hydrophobically modified cellulose particles. This work provided a facile method for the modification of cellulose microparticles with amphiphilic properties and enhanced emulsifying capacity. The cellulose based particles with biocompatible and environmentally friendly characteristics would be attractive for the applications in biomedicine, pharmaceuticals, cosmetics, etc. [ABSTRACT FROM AUTHOR]

Physical instability and oxidation were two of the most evident problems existing in food emulsions. In this research, a facile approach of solidifying the oil phase by stearic acid was adopted to overcome the above problems simultaneously, emphasising the effect of the oleogelation extent. Polarizing microscope, rheological analysis, and X-ray diffraction (XRD) were used to characterize the oleogelation of the oil phase, and droplet size, microscopic observation and peroxide value analysis were applied to evaluate the emulsion stability. Results showed that with moderate solidification of the oil phase (0.8%–1.0% w/v stearic acid in oil phase), the emulsions exhibited excellent physical stability under the stress of centrifugal force, high salt, and long-term storage. Moreover, the oxidative stability of the emulsions was improved simultaneously, that the increasing of peroxide value was slowed significantly. Excessive solidification (e. g. 3% w/v stearic acid) of the oil phase would weaken these advantages or even bring about opposite results, due to the destruction of the emulsion droplets by the excessive crystallization. Our results suggested that moderate solidification of oil phase would be a feasible and effective approach to improve the stability of o/w emulsions, which would be significant for the industrial-scaled production. • Stearic acid could be used to prepare the starch stabilized oleogel emulsions. • Oleogelation of the oil phase could improve the physical stability of the emulsions. • Lipid oxidation could be inhibited in the oleogel based emulsions. • The emulsion stability was related to the solidification extent of the oil phase. [ABSTRACT FROM AUTHOR]

• Medium/high internal phase Pickering emulsions were obtained by the sole use of BCNFs. • The obtained Pickering emulsions revealed low coalescence rate and excellent stability. • Medium/high internal phase Pickering emulsions exhibited typical shear-thinning behaviors and solid-like properties. • This one-step method was eco-friendly without using any surfactants and organic solvent. O/W Pickering emulsions containing oil phase with different volume fractions (50–75 v%) were facilely prepared by using bacterial cellulose nanofibrils (BCNFs) alone. The effect of oil phase volume, storage time on the surface coverage, and coalescence rate of the Pickering-MIPEs and HIPEs (medium internal phase emulsions/high internal phase emulsions) were investigated. The Pickering-MIPEs/HIPEs exhibited excellent physical stability and low coalescence rate with droplet size varying from 32 to 91 μm. The increasing of particle contents could obviously decrease the droplet size and enhance the stability of the emulsions by strengthening the network structure and increasing the steric hindrance. The result of rheology analysis confirmed the formation of a three-dimensional network, endowing the exceptional stability of the emulsions. The emulsions revealed superb stability against a wide temperature (4–50 °C) range and salt condition (0–100 mM). This novel eco-friendly Pickering-MIPEs and HIPEs would provide great opportunities for their effective utilization in green-labelled food industry. [ABSTRACT FROM AUTHOR]

Abstract In this work, high pressure homogenization (HPH) was applied to alter the physical size of bacterial cellulose, and the obtained bacterial cellulose nanofibrils (BCNFs) with different size were used as stabilizers for O/W Pickering emulsions. The average width of the BCNFs was decreased from 127 to 97 nm with the increasing the homogenized times from 10 to 80 times at 750 Bar, and the obtained BCNFs suspensions was pseudoplastic fluid and exhibited a typical shear thinning behavior. The physical size of the BCNFs had an obvious influence on their emulsifying capacity, and the surface coverage ratio of the emulsion droplets was increased from 0.63 to 9.77 with the changing the volume of oil and solid content of BCNFs. Moreover, the temperature, ionic strength and pH had insignificant influence on the stability of the emulsion. It suggested that the flexible BCNFs played an important role in the stabilization of the emulsions, and the higher content of BCNFs increased the intermolecular noncovalent "physical" cross-links. Moreover, stable medium-internal-phase-emulsions (MIPEs) could also be fabricated by using BCNFs as stabilizers. Graphical abstract Image Highlights • HPH process was used to change the physical sizes of bacterial nanocellulose. • The effect of the physical sizes of bacterial nanocellulose on the performance of the emulsions had been clarified. • Stable medium-internal-phase-emulsionscould could be prepared by using bacterial nanocellulose. [ABSTRACT FROM AUTHOR]

Although polysaccharide microgels exhibit potential as clean-label emulsifiers, the stability of emulsions in commercial application is still a challenge. The current work points out that specific complexation between polysaccharide molecules and polysaccharide microgels can benefit the interfacial adsorption of polysaccharide microgels and emulsion stability. The complexation of κ-carrageenan microgels (KCMs) and locust bean gum (LBG) was investigated for the first time, which was evaluated by visual appearance, rheological behavior, thermal stability, and microscopic morphology. Results indicate the low concentration of LBG promotes the clustering of KCMs, whereas high concentration of LBG can envelop and segregate KCMs. Subsequent blending with LBG could enhance the interfacial adsorption of KCMs, and multi-layers are observed when LBG concentration exceeds 0.3 wt%. LBG can obviously decrease the emulsion droplets size and improve the storage stability of emulsions, KCMs + LBG (0.2–0.5 wt%) stabilized emulsions could keep stable after three consecutive freeze-thaw cycles. Based on the specific complexation between KCMs and LBG, the layer-by-layer emulsification could be achieved. This strategy can inspire other polysaccharide microgel emulsifiers, which could be a feasible solution for improving the stability of polysaccharides microgels stabilized emulsions. [Display omitted] • Locust bean gum (LBG) could complex with κ-carrageenan Microgels (KCMs). • Complexation pattern of LBG and KCMs at aqueous phase was identified. • Interfacial complexation of LBG and KCMs improves emulsion stability. • Interfacial complexation endows emulsions with improved freeze-thaw stability. [ABSTRACT FROM AUTHOR]

In this study, beeswax (BW)/soybean oil (SO) mixed lipid phase and bacterial cellulose nanofibrils (BCNF)/gelatin (GLT) hybrid stabilizers were utilized to prepare O/W emulsions, which were applied as templates to fabricate solid lipid particle (SLP) dispersion for further preparing oleofilms. As the BW content (based on lipid phase) increased from 10 to 40 wt%, the SLP size became smaller, and the obtained oleofilms showed significant variations in the structure that more lipid crystals distributed on the film surface and film exhibited increased crystallinity. The film prepared with SLP with 40 wt% BW (based on lipid phase) had the best light barrier property, largest contact angle (96 ± 1o) and lowest water vapor permeability (WVP, 4.4 ± 0.1 × 10−8 g m−1·h−1·Pa−1), but the lowest tensile strength (1.53 ± 0.11 MPa) and elongation at break (2.32 ± 0.16%). The SLP dispersion was further ultrasonically treated (SLP-U) for improving the physical property of oleofilms. Compared to SLP oleofilms, SLP-U oleofilms possessed more uniform micro-structure, better transparency, and higher mechanical strength, revealing that SLP-U had higher adhesion with biopolymer matrix. The increase of BCNF ratio contributed to the significant decrease in the SLP-U size, improved the oleofilm contact angle, but reduced the film mechanical strength. This study provided the regulation method of acceptable barrier and mechanical properties for oleofilm by properly tailoring the lipid particle property. [Display omitted] • Solid lipid particle (SLP) dispersion was prepared based on emulsion template. • SLP size was impacted by emulsion composition and further ultrasonic treatment. • Oleofilms were fabricated by one-step drying the SLP dispersion. • Oleofilms showed excellent barrier performance and controllable mechanical strength. [ABSTRACT FROM AUTHOR]

• The food-grade W/O emulsions based on oleogels had no surfactant. • Beeswax played a decisive role in stabilizing the W/O emulsions. • The W/O emulsions exhibited high stability during 60 d storage. • The W/O emulsions performed excellent thermo-reversible and thixotropic properties. • The W/O emulsions would have promising potential as fat mimetics. Fabrication of food-grade water-in-oil (W/O) emulsions without surfactant, as the primary substitutes of trans -fat and saturated fat, was still a significant challenge in food science. A facial method has been adopted to fabricate W/O emulsions at 20 °C. The obtained emulsion had long-time stability, and there was no apparent phase separation or oiling-out after 60 days of storage. In this system, beeswax served as a stabilizer for both oleogels and oleogel-based emulsions. The sol–gel melting temperature of the oleogel was 37 ± 0.5 °C by regulating beeswax content to 4% w/w, and then the oleogel was used to fabricate W/O emulsion with the droplet diameter of around 9 μm. Thermo-reversible and thixotropic properties of oleogels were both retained for emulsions. Furthermore, both oleogels and oleogel-based emulsions had compact gel-like structures. The self-emulsifying W/O emulsions without surfactant would have great potential applications in food industry, pharmaceutical industry and feed industry. [ABSTRACT FROM AUTHOR]

Hexadecyltrimethylammonium bromide complexed alginate-Ca2+ microgels (C/AMGs) were developed as emulsifiers, which shown remarkably improved emulsifying performance than non-complexed alginate-Ca2+ microgels (AMGs) in previous study. This work focus on the impact of deformability on the emulsifying performance of C/AMGs. By regulating alginate concentration (1.0–4.0 wt%), microgels with different deformability were prepared. Deformability was proved to have great influence on the emulsifying performance of C/AMGs, which was evaluated by Langmuir trough measurements, emulsion appearance, centrifugation stability, digestive behavior, and oxidative stability. Particle size and SEM images indicated microgels prepared with lower alginate concentration are more deformable. C/AMGs (2.0 wt%) exhibits the best emulsifying performance, which could be ascribed to the appreciated deformability and mechanical strength. Digestive behavior and oxidative stability of alginate-Ca2+ microgel (2.0 wt%) stabilized emulsions were further investigated. Compared with alginate-Ca2+ microgel (2.0 wt%) stabilized emulsions, C/AMGs (2.0 wt%) stabilized emulsions shown delayed lipid digestion and lower POV. Results of this work supporting that Mickering mechanism have potential in fabricating functional emulsions based on natural polysaccharides. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple method to observe the oxygen diffusion in the emulsion system was developed. • The oxygen diffusion was strongly related to the lipid oxidation in emulsion. • The emulsion droplet surface could affect the oxygen diffusion and lipid oxidation. • The oil phase and water phase could affect the oxygen diffusion and lipid oxidation. Oxygen diffusion played an important role in the lipid oxidation of food emulsions. In this study, a simple method was developed to quantitatively observe the oxygen diffusion in the oil–water biphasic system, and it was further applied to investigate the relationship between the oxygen diffusion and lipid oxidation in O/W emulsions. Various factors that related to the emulsion oxidation were considered, from their influence on the oxygen diffusion and lipid oxidation in the emulsions. Results showed that there was obvious correlation between the oxygen diffusion and lipid oxidation in O/W emulsions, which reveals the inhibition of oxygen diffusion could apparently slow down the lipid oxidation. Moreover, the changes of oil phase, water phase and interfacial layer of the emulsions, which were related to the oxygen diffusion, could improve the oxidative stability of the emulsions effectively. Our findings are helpful for deep understanding the mechanisms of the lipid oxidation in food emulsions. [ABSTRACT FROM AUTHOR]

In the current study, complexes (CAMs) of alginate microgels (AMs) and hexadecyltrimethylammonium bromide (CTAB) were prepared, and further used to stabilize O/W emulsions. Physical properties and emulsifying capacity of CAMs with different CTAB concentration were investigated, which indicated emulsifying capacity of AMs could be extensively improved by CTAB. Improved stability against centrifugation (3000 rpm), pH value (2.0–8.0), and NaCl concentration (0–200 mM) was also reported in CAMs stabilized emulsions. Interfacial adsorption and morphology observation suggested that the interfacial activities of CAMs were benefited from CTAB complexing, and an interfacial layer could be observed on the surface of the CAMs stabilized oil droplets. In this work, even a slight amount of surfactant (0.4 mM, or 0.01456 wt% CTAB) could make remarkable improvement on the emulsifying performance of alginate microgels. However, excessive CTAB would result in over aggregation of AMs, which was not conducive to the emulsifying performance of CAMs. This study proposed that the surfactant complexing was a feasible strategy to improve the emulsifying performance of polysaccharide microgels. [Display omitted] • Emulsions based on Ca2+-alginate microgels (AMs) were manufactured. • Slight CTAB was complexed with AMs (CAMs) to improve its emulsifying properties. • Excessive CTAB leads to deteriorated emulsifying properties of CAMs. • CAMs stabilized emulsions exhibit remarkable stability. [ABSTRACT FROM AUTHOR]

Agarose microgels were prepared with bottom-up approach, and emulsifying properties of agarose microgels were investigated. Physical properties of microgels are varied with agarose concentration, and further affect the emulsifying performance of microgels. Enhanced surface hydrophobicity index and decreased particle size of microgels were recorded with the increasing of agarose concentration, which were conducive to emulsifying properties of microgels. Improved interfacial adsorption of microgels was evidenced by Dynamic surface tension and SEM. However, microscopic morphology of microgel at O/W interface indicated that increasing agarose concentration could weaken the deformability of microgels. The influence of external conditions (pH and NaCl) on the physical properties of microgels were investigated, and their effects on emulsion stability were evaluated. Compared with acidification, NaCl was appeared to be more destructive to emulsion stability. Results indicated acidification and NaCl could decrease surface hydrophobicity index of microgels, but there was differentiation in the variation of particle size. It was inferred that deformability of microgels could make contribution to the stability of emulsion. This study verified that microgelation was a feasible scheme to improve the interfacial properties of agarose, and the influence of agarose concentration, pH, and NaCl on the emulsifying performance of microgels was investigated. The emulsifying performance of agarose microgels, which could be affected by agarose concentration, pH value, and NaCl. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, the effect of bacterial cellulose nanofibrils (BCNF) surface charge density on the emulsification capacity of gelatin (GLT)/BCNF mixtures was investigated. Emulsions with 50 v% oil phase were co-stabilized by GLT and BCNFs (surface charge densities varied from 0.34 to 1.16 mmol/g) at pH 7.0 (GLT and BCNFs were negatively charged) and pH 4.7 (electrostatic equilibrium point for all GLT/BCNF mixtures). At pH 7.0, as BCNF surface charge density increased, the oil-water interfacial tension was decreased. Thus, the emulsion droplet size was reduced from 14.24 to 13.51 μm when the BCNF surface charge density was improved from 0.34 to 1.16 mmol/g. Additionally, the emulsion stability was significantly improved by the addition of highly-charged BCNF due to the increased electrostatic repulsion between dispersed droplets. At pH 4.7, the highest level of attractive electrostatic interaction was observed for GLT and BCNF with a surface charge density of 1.16 mmol/g (BCNF 1.16). Thus, the GLT/BCNF 1.16 suspension exhibited the highest viscoelastic modulus. At pH 4.7, the stability of GLT/BCNFs co-stabilized emulsions was improved by increasing BCNF surface charge density due to the enhanced viscosity. The emulsions prepared with GLT and BCNFs with surface charge density higher than 0.66 mmol/g at pH 4.7 could keep stable without creaming for 30 d. Furthermore, the GLT/BCNF 1.16, with the most remarkable emulsion stabilizing capacity, was successfully applied to prepare high internal phase emulsions with a more stable and higher viscoelastic behavior. This study was meaningful for the regulation of emulsion stability and rheological property. [Display omitted] • BCNFs with different surface charge densities were prepared by TEMPO oxidation. • Emulsions were prepared with GLT/BCNF mixtures at pH 7.0 and 4.7. • The interfacial adsorption of GLT/BCNF was influenced by BCNF surface charge density. • Emulsion stability was improved by the enhancement of BCNF surface charge density. [ABSTRACT FROM AUTHOR]

It has been a great challenge of using natural polysaccharides to stabilize food emulsions, due to their poor amphiphilicity. In this study, a novel strategy of using polysaccharide to stabilize O/W emulsions was developed, through in situ crosslinking of sodium alginate on oil-water interface. During the emulsifying process, the acetic acid migrated across the interface, and induced the released of calcium ions, which immediately crosslinked the sodium alginate on interface. Results showed that the oil droplets were encapsulated in the integral polysaccharide shells. The droplet size of the emulsions located in the range from 20 to 200 μm. The concentration of sodium alginate and HAc, as well as the mixing rates were showed to be positively related with the thickness of the shell. However, excess calcium ions would disintegrate the shell structure. Additionally, the interfacial crosslinked sodium alginate stabilized emulsions exhibited excellent physical stability under centrifugating and freeze-thawing. [Display omitted] • Emulsions based on in situ crosslinking of alginate were manufactured. • Oil droplets were encapsulated in the integral polysaccharide shells. • Influence of different factors on shell thickness of oil droplets was evaluated. • In situ crosslinking of alginate endow emulsions with excellent physical stability. [ABSTRACT FROM AUTHOR]