Storage Stability Of Emulsions Research Articles

Kinetic stability, gastrointestinal fate, and cytotoxicity of vitamin D3 emulsion incorporated with cricket protein-fructooligosaccharide conjugate

Vitamin D3 stability has been a concern in the functional food industry. Protein conjugated with saccharides showed potential for an improvement in vitamin D3 stability. Novel and sustainable proteins, such as cricket protein, are of interest worldwide. Therefore, this research examined the utilization of cricket protein-fructooligosaccharide (FOS) conjugates formed through the Maillard reaction as a delivery system for vitamin D3 in an oil-in-water (O/W) emulsion. O/W emulsions with vitamin D3 stabilized by cricket protein powder (CP), cricket protein-FOS mixture (CPM), and cricket protein-FOS conjugates (CPF) with varying concentrations (0.3%, 0.5%, and 1.0% w/v). All emulsions had di-modal distributions with mean particle size diameters (D [4,3]) between 4.17 and 12.62 μm. The CPF emulsion had larger particle size diameters (8.46–12.62 μm) but less span value (3.26–4.76) when compared with CP and CPM (4.17–5.88 μm, 4.87–6.38). The storage stability of emulsions and vitamin D3 release (4 °C, 0–30 days) was improved by conjugated products. The CPF-stabilized vitamin D3 emulsions exhibited enhanced vitamin D3 bioaccessibility (37–54%), surpassing that of CP (27–34%) and CPM (32–37%). Furthermore, CPF showed superior vitamin D3 stability during in vitro gastrointestinal digestion. The concentration required for 50% inhibition of cell viability of CP, CPM, CPF, and CPF-vitamin D3 emulsion was 0.643, 0.552, 0.474, and 0.229 mg/mL, respectively, indicating low cytotoxic activity. These findings validate the effectiveness of cricket protein-FOS conjugates, particularly at a 1% (w/v) concentration, in improving the release of vitamin D3 in emulsion-based delivery systems and their potential for fortifying functional food products.

Construction of benzyl isothiocyanate-loaded fish skin gelatin-luteolin compound emulsion delivery system, and its digestion and absorption characteristics.

Fish skin gelatin (FSG) and luteolin (LUT) were used as composite emulsifiers, and benzyl isothiocyanate (BITC) was used as a model of nutrient delivery to construct a stable emulsion. The storage stability of the FSG-LUT emulsion and its effect on BITC release were investigated both in vitro and ex vivo. LUT can quench FSG fluorophores statically and form a stable complex through hydrogen bonding and hydrophobic interactions. The FSG-LUT emulsion storage stability and embedding rate were higher than those of the FSG emulsion. The FSG-LUT emulsion microstructure was resistant to oral and gastric digestion, and the BITC retention rate and bioaccessibility were much higher than those of the FSG emulsion. Lastly, the ex vivo everted gut sac of rat intestine study demonstrated that BITC showed the highest absorption in the ileum, and the FSG-LUT emulsion absorbed BITC and sustained a controlled release in a specific position. LUT could form stable complexes with FSG, which improved the stability and bioavailability of BITC in the FSG-LUT emulsion delivery system, and promoted further intestinal BITC absorption. © 2022 Society of Chemical Industry.

Enhancing the interfacial stability of O/W emulsion by adjusting interactions of chitosan and rice protein hydrolysate

The influences of chitosan and rice protein hydrolysate (CH/RH) ratio and oil-water ratio on the emulsification efficiency, as well as the impact of RH on the formation of CH/RH complex coacervates was investigated. Emulsions prepared by CH/RH at different concentrations (1–4%) were also evaluated. Higher proportion of CH led to an increase in turbidity, ζ-potential, and particle size and a decrease in surface hydrophobicity of CH/RH. The ζ-potential and droplet sizes of CH/RH stabilized emulsions increased with increasing CH proportion at different oil-water ratios. The formation of strong network due to electrostatic interaction between CH and RH, possessing amphiphilicity contributed by hydrophobicity of RH and hydrophilicity of CH, improve emulsion stability. The CH/RH complexes at ratio of 1:1 can form more stable emulsion as oil volume fraction from 20% to 80%. CH/RH 1:1 emulsion had greater viscosity and storage/loss modulus values than other CH/RH complexes, followed by CH/RH 1:2 at oil fraction ≥50%. Higher oil fraction (60% and 80%) enhanced the viscosity while decreased the emulsion storage stability. Increasing CH/RH concentration can help to form a thicker and stronger interfacial layer on the droplets and a more stable network structure, thus enhancing emulsion stability. Overall, CH/RH 1:1 is more effective in enhancing the interfacial adsorption and emulsification stability than CH or RH alone, especially at 50% oil volume fraction. This study may contribute to the potential of CH/RH complexes for stabilizing emulsion system at different oil contents applied in different food formulations.

Enhanced Bioaccessibility of Microencapsulated Puerarin Delivered by Pickering Emulsions Stabilized with OSA-Modified Hydrolyzed Pueraria montana Starch: In Vitro Release, Storage Stability, and Physicochemical Properties.

Puerarin is a bioactive flavonoid isolated from Kudzu roots that possesses numerous health benefits. However, its poor bioavailability and existing complex delivery systems with safety issues are challenging tasks for its incorporation into functional foods. Preparing modified-starch-stabilized Pickering emulsions containing microencapsulated puerarin with improved bioaccessibility was the key objective of the present research work. Acid-hydrolyzed high-amylose Pueraria montana starch (PMS) was modified with octenyl succinic anhydride (OSA) and evaluated as an emulsifier to prepare emulsions. The FTIR, SEM, and XRD results showed that PMS was successfully modified. Furthermore, the emulsification index (EI), mean droplet size, and ζ-potential values showed that modified starch with a higher degree of substitution (DS) enhanced the storage stability of emulsions. Similarly, the retention degree and encapsulation efficiency results of puerarin proved the assumption after storage of 16 d. The Pickering emulsions also helped in the controlled release of microencapsulated puerarin in vitro. The study outcomes proved that Pickering emulsions stabilized with OSA-modified PMS have promising applicability in functional foods as efficient food-grade delivery systems, enhancing oral supplementation and accessibility of puerarin.

Carboxymethyl chitosan-based electrospun nanofibers with high citral-loading for potential anti-infection wound dressings

As a natural antibacterial agent with pleasant fragrance, citral possesses low aqueous solubility. To improve citral loading in hydrophilic nanofiber, Pickering emulsion electrospinning strategy was proposed for anti-infection dressing development. The in-situ aggerated β-cyclodextrin-citral inclusion complex particles (βCPs) were used as emulsion stabilizers, while citral and carboxymethyl chitosan (CMCS)/polyvinyl alcohol (PVA) mixed solutions were used as the inner “dispersed oil phase” and outer “continuous water phase”, respectively. The results of electronic microscope investigation shown βCPs possessed regular cube appearances with a size of 5.5 ± 2.2 μm, which might improve the emulsion storage stability based on visual investigation. Moreover, randomly oriented and bead-on-string nanofibers with βCPs uniformly distributed could be obtained under optimized compositions and electrospinning parameters. Despite volatilization during electrospinning, nanofibers with high citral loading possessed good antibacterial performance against Staphylococcus aureus and Escherichia coli. In vitro hemolysis test indicated that nanofibers were hemocompatible. In addition, both fiber matrix and citral could promote the proliferation of mouse fibroblast cells. And the permeability of the fibers was adjustable. Thus, CMCS/PVA/βCPs/citral nanofibers could potentially protect wound from infection. In summary, CMCS/PVA/βCPs/citral nanofibers seemed to be promising alternatives to conventional wound dressings.

Mechanically robust and self‐healing waterborne polyurethane nanocomposites based on inorganic organic hybrid materials and reversible covalent interaction

AbstractEndowing waterborne polyurethane (WPU) materials with mechanically reinforced and self‐healing property is a pressing issue for expanding practical applications. In this article, we proposed a simple method to give WPU with self‐healing properties while improving the mechanical properties. First, furfuryl‐modified silica nanoparticles (furan@SiO2) with high functionality and excellent dispersibility were prepared by the sol–gel method. Furan@SiO2 was then introduced into the side‐hanging maleimide WPU to form a thermally reversible inorganic–organic network (WMSPUS‐x) based on the Diels‐Alder reaction. The morphologies and properties of furan@SiO2 and WMSPUS‐x emulsions were analyzed by TEM and DLS, demonstrating the excellent dispersion of furan@SiO2 and the storage stability of emulsions. The cross‐linking density of the nanocomposites was varied by the furan@SiO2 contents, and the effects of cross‐linking density on mechanical and self‐healing properties were systematically investigated. In addition, the thermal stability of WMSPUS‐x nanocomposites was significantly improved shown by TGA results. Finally, qualitative and quantitative studies of the self‐healing process were carried out to verify that WMSPUS‐x nanocomposites possess great self‐healing capacity. The outcomes indicate that WMSPUS‐x nanocomposites have great potential for application as a smart material.

Food-grade olive oil Pickering emulsions stabilized by starch/β-cyclodextrin complex nanoparticles: Improved storage stability and regulatory effects on gut microbiota

The beneficial effects of olive oil consumption make it be one of the leading healthy edible oils worldwide. However, the water insolubility and oxidation of olive oil hinder its applications. In this study, food-grade oil-in-water olive oil Pickering emulsions (OOPEs) stabilized by hybrid starch/β-cyclodextrin nanoparticles (starch/β-CD NPs) was developed and characterized. The starch/β-CD NPs concentration and oil phase fraction had a significant influence on the droplet size, zeta potential and storage stability of emulsions. Confocal laser scanning microscopic observation revealed that the starch/β-CD NPs mainly located at the interface of oil droplets, forming a network structure to stabilize emulsions. Rheological analysis indicated the shear-thinning behavior and gel-like structure of starch/β-CD NPs stabilized OOPEs. Additionally, the obtained OOPEs remarkably improved the oxidative stability and storage stability by inhibiting the lipid oxidation compared to pure olive oil. Furthermore, animal experiments indicated that OOPEs modulated the gut microbiota in mice with an enhanced richness and diversity, resulting in an increased abundance of health-promoting bacteria. Notably, high-dosage OOPEs significantly decreased the ratio of phyla Firmicutes/Bacteroidetes. These findings could facilitate the development of olive oil Pickering emulsion with excellent stability and health effects on gut microbiota for applications in foods.

Scallops as a new source of food protein: high‐intensity ultrasonication improved stability of oil‐in‐water emulsion stabilised by myofibrillar protein

SummaryIn this study, the effect of high‐intensity ultrasound (HIUS) (200 and 400 W for 0, 5, 10 and 15 min respectively) on conformational changes, physicochemical, rheological and emulsifying properties of scallop (Patinopecten yessoensis) myofibrillar protein (SMP) was investigated. HIUS‐treated SMP had lower α‐helix content and higher β‐sheet content compared with the native SMP. HIUS treatment induced the unfolding of SMP and increased the surface hydrophobicity. The particle size of SMP decreased and the absolute zeta‐potential increased after ultrasonication, which in turn increased the solubility of SMP. The conformational changes and the improvement of physicochemical properties of SMP increased the ability for SMP to lower the interfacial tension at the oil–water interface and increased the percentage of adsorbed protein. As a result, the emulsifying properties, rheological properties of SMP and storage stability of emulsions were also improved. In conclusion, HIUS treatment has future potential for improving the emulsifying properties of SMP.

Synergetic effect of asphaltenes extracted from polymer containing oil sludge and HPAM at water/toluene interface

The interaction between asphaltenes and hydrolyzed polyacrylamide (HPAM) at the oil-water interface is the key factor leading to the stability of polymer-containing wastewater/oil sludge in the oilfield. In this study, the asphaltenes extracted from polymer-containing oil sludge were systematically characterized and the interaction between asphaltenes and HPAM at the toluene/water interface was studied. We found that asphaltenes had a moderately aromatic structure and a large number of fatty chains. There was a strong π-π stacking interaction among asphaltenes molecules. Asphaltenes and HPAM could reduce the interfacial tension of oil/water, increase the interfacial dilatational modulus, and enhance the stability of emulsion synergistically. Both the asphaltenes concentration and the HPAM concentration affected the interfacial stability. With the changes of the two components concentrations, there was a synergistic or competitive effect between asphaltenes and HPAM at the toluene/water interface. At low concentrations of asphaltenes (Casphaltenes = 100 ppm) the addition of HPAM (CHPAM = 300 ppm) reduced the interfacial tension by 0.52 ± 0.17 mN/m, improved the dilatational modulus by 7.75 ± 0.4 mN/m (the growth rate was 57.33%), asphaltenes molecules and HPAM molecules co-adsorbed on toluene/water interface. For the high concentration of asphaltenes (Casphaltenes = 500 ppm), the addition of HPAM (CHPAM = 300 ppm) rarely reduced the interfacial tension, a few increased the dilatational modulus by 0.69 ± 0.15 mN/m, asphaltenes molecules competed with HPAM molecules to adsorb on toluene/water interface. The presence of HPAM in the aqueous phase changed the emulsion from water-in-oil type (W/O) to oil-in-water type (O/W). The increase of asphaltenes and HPAM concentration is beneficial to the increase of emulsion interfacial film strength (the addition of HPAM increased the yield stress of emulsion interfacial film by 22 times) and the enhancement of emulsion storage stability of 100% maximum. These results provided a theoretical foundation for treating polymer-containing oil sludge in oil fields.

High protein and high oil emulsions: Phase diagram, stability and interfacial adsorption

Whey protein isolate (WPI), sodium caseinate (SC) and soy protein isolate (SPI) and three kinds of oils were used to prepare high protein and high oil emulsions. The phase diagrams of the ternary system were constructed after homogenization, sterilization and storage. The results showed that the chain length and saturability of oils had little effect on the storage stability of emulsion. When the oil was 10% MCT, excellent storage stability was achieved by 1–4% WPI-stabilized emulsions, 1–3% and 10% SC-stabilized emulsions, and 1–6% SPI-stabilized emulsions. Nitrogen solubility index and surface hydrophobicity of SPI (39% and 663) were both significantly lower than those of WPI (97% and 1303) and SC (95% and 2207). WPI changed from monolayer adsorption to multilayer adsorption with the protein concentration from 4% to 6%. SC reached saturated adsorption when the protein concentration was higher than 2%. For WPI, β-LG and α-LA decreased significantly with the increase of protein concentration, while small aggregates increased significantly and showed the superiority at 4% content. For SC, the superior position on the interface with the increase of protein concentrations changed from β-casein to α-casein. For SPI, the aggregates exhibited the superior position and increased with the increase of protein concentrations.

Ultrasonication of mayonnaise formulated with xanthan and guar gums: Rheological modeling, effects on optical properties and emulsion stability

The present research explored the potential of probe ultrasound homogenizer and hydrocolloids in formulating and stabilizing mayonnaise. The effect of ultrasonic (US) treatment (12 min at 20%, 30%, 40% amplitude) and stabilizers xanthan gum (XG; 0.5% w/w), guar gum (GG; 0.5% w/w), and XG/GG (1:1) on emulsion storage stability (ESS), physicochemical and rheological properties of mayonnaise were studied. Rheological data comprising of shear rate (γ˙) and shear stress (τ) was analysed through four different rheological models (Herschel–Bulkley, Casson, Power Law, and Carreau-Yasuda models), and their fitness was evaluated. The samples exhibited non-Newtonian, pseudoplastic behaviour with flow behaviour index (n) < 1 and consistency index (K) 43.58–72.38 Pa sn. The apparent viscosity measured at a shear rate of 0–20/sec, was decreased steeply, by the application of 40% amplitude, most prominent in GG samples (1007 Pa s to 608 Pa s) while compared with XG (1625 Pa s to 1304 Pa s). The increase in US amplitude caused a linear increase in the refractive index (ranging from 1.3681 to 1.3791) and decreased pH (ranging from 3.686 to 3.523). A significant reduction in whiteness (L* value) from 78.300 to 73.860 was noted for XG/GG (1:1) samples. The ESS decreased with an increase in US amplitude, and 40% US amplitude-modulated GG sample had the least ESS (90.14%) among all treated and control samples. However, treated samples had higher ESS than the market sample (86.50%).

The effect of essential oil chemical structures on Pickering emulsion stabilized with cellulose nanofibrils

Nanocelluloses are non-toxic and biodegradable biopolymers with high potential for application as solid emulsion stabilizers. In this work, cellulose nanofibrils were used a Pickering emulsion stabilizer for different essential oils (cinnamon cassia, cardamom, and ho wood). Emulsions were evaluated by droplet sizes, microstructure, emulsion storage stability, stability towards shear, rheological behavior, and FT-Raman. The droplets showed spherical shapes and an average diameter ranging from 10 to 20 μm, depending on the essential oil physicochemical properties and CNF-surface coverage (SC). CNF-Cardamom showed the highest SC values, indicating that CNF formed an interconnected three-dimensional network around the oil droplets, and CNF-Ho wood showed the lowest values, directly reflecting in the emulsion stability. The rheological data evidenced the network formation in the CNF-emulsions and their pseudoplastic behavior, and CNF-cardamom showed the strongest network structure, resulting in a higher thixotropic hysteresis loop area (398 s−1). The FT-Raman analysis was decisive to correlate the emulsion stability with the EO chemical structure. Cardamom and Cinnamon chemical structures are stable, and the electron pairs in resonance favor the electronic attraction between the components, resulting in a steric stabilization, forming a cellulose nanofibers three-dimensional network. Ho wood has the most reactive chemical structure, and CNF addition induced the hydrogen bonding between both materials, forming a monolayer around the oil drops and inducing droplets coalescence. This work correlated the EO stabilization with the CNF morphology and highlighted the importance of the compounds' chemical structure in the emulsions' stability, which are essential for further studies in Pickering emulsion essential oils CNF-stabilized.

Emulsifying properties of acid-hydrolyzed insoluble protein fraction from Chlorella protothecoides: Formation and storage stability of emulsions

Microalgae are promising alternative protein sources due to their high protein content. However, the techno-functional properties of microalgae proteins are limited by their high content of insoluble proteins. Recently though, it has been reported that hydrolysis with 0.5 M HCl improved their solubility and interfacial activity, which could enhance their ability to act as emulsifying agents. In this study, we, therefore, investigated the use of an insoluble microalgae protein fraction from Chlorella protothecoides as oil-in-water emulsifiers after hydrolysis at 65 °C and 85 °C for 4 h. Mean particle diameter, microscopic images, and ζ-potential of emulsions stabilized by untreated insoluble microalgae protein fraction and their hydrolysates at different protein concentrations (1%–5%) were recorded during storage for 14 days. Results showed that emulsions prepared by untreated and hydrolyzed protein fractions all exhibited droplet flocculation, but effective droplet size decreased with increasing protein concentrations and storage time. Moreover, emulsions droplets were stable against coalescence at protein concentrations ≥3%. Overall, hydrolysates showed higher interfacial activities compared to untreated microalgae proteins. Results were attributed to the presence of protein aggregates causing droplet flocculation, and mixed protein aggregate - hydrolyzed peptide interfaces preventing coalescence. Results indicated a potential application of hydrolysates of insoluble microalgae protein fraction in emulsion-based foods, especially concentrated emulsions, such as mayonnaise, dips or salad dressings.

Formation of Pickering and mixed emulsifier systems stabilised O/W emulsions via Confined Impinging Jets processing

This study investigates for the first time the production of 10 and 40wt.% oil-in-water emulsions stabilised by an array of particles and mixed emulsifier (Tween20-silica) concentrations. CIJs performance was evaluated for a range of hydrodynamic conditions (energy dissipation rates, ε¯th) and multipassing through the CIJs geometry followed by a monitoring of the emulsion storage stability. Overall, it was demonstrated that droplet size reduction was promoted as higher energy levels of ε¯th were approached, regardless of the formulation. Following emulsion recirculation under fixed jet mass flow rate, the residence time associated with two passes was sufficient to ensure no further changes in terms of both average droplet size (d3,2) and span of the droplet size distribution. Only when Tween20 and silica were mixed at low concentrations (0.01 and 0.10wt.%, respectively), this emulsifier system could not promote any droplet size reduction upon both processing and multipassing. All systems showed excellent stability over 40 days of storage and it was possible to demonstrate that the combination of the emulsifiers aided in prolonging the emulsion stability. In conclusion, this investigation aims to extend the current range of emulsion microstructures that can be produced by CIJs to further enhance its industrial applicability.

Emulsification properties of amylose-fatty sodium salt inclusion complexes

Amylose complexes formed with fatty sodium salts were evaluated for their emulsification, foaming, and rheological properties. Amylose inclusion complexes (AIC) were produced in a pressurized microwave reactor using the sodium salts of fatty acids having carbon chain lengths of 12–22. The AIC were isolated by freeze drying, re-dissolved into aqueous solutions (0.1–3.0% solids) and their surface and rheological properties were then characterized. The AICs successfully formed emulsions with corn oil. The emulsifying properties of the various AIC, as well as long-term emulsion storage stability were determined. The AIC have superior emulsifying activity at neutral and alkaline pH, and superior stability at alkaline pH, compared with commercial octenyl succinic anhydride (OSA) starch. In neutral aqueous solutions, the sodium arachidate (C20) AIC had 31% greater emulsifying activity, and the sodium behenate (C22) AIC had 60% greater emulsion stability than OSA starch. Emulsions formed with the AIC were stable during long-term storage as the oil droplets were resistant to coalescence. Stability increased with fatty acid salt chain length due to viscosity differences, with solutions of the higher molecular weight fatty acid salt AICs having greater viscosity. All AIC emulsions had enhanced emulsifying activity with increased alkalinity of the continuous phase. The AIC are surface active polymeric emulsifiers which did not produce foams. The AIC are effective biodegradable emulsifiers produced from readily available inexpensive food grade ingredients formed via van der Waals rather than chemical bonds.

Surface engineered bacteria as Pickering stabilizers for foams and emulsions

The ability to manipulate the structure of food and increase the shelf life by enhanced stability using natural (e.g., biological) agents instead of synthetic surfactants is of interest to many food companies. Here we chemically modify the cell hydrophobicity of lactic acid bacteria Lactobacillus acidophilus (La5) using octenyl succinic anhydride (OSA) and investigate foams and emulsions produced with both the unmodified and modified cells in terms of the foamability, foam stability, emulsion storage stability and the microstructure. Cell hydrophobicity was effectively increased by OSA modification, and the modified bacteria adsorbed well on the oil-water or air-water interface to stabilize the foams or emulsions. Foamability and foam stability increased with OSA modification. Similarly, good emulsion stability against coalescence was observed over the studied period for the emulsions prepared with modified La5. Moreover, OSA modification only showed a modest lethal effect up to 6% OSA on bacteria based on the decline of cell viability and culturability depending on the degree of modification (0.5 log decrease for 6% OSA-modified cells but 5 log decrease for 10% OSA-modified cells in comparison to culturability of unmodified cells). From our results, we suggest that in future OSA-modified La5 cells may act as structural building blocks and fat substitution for food material creating texture and mouthfeel.

Effect of electrochemical modification on the structural characteristics and emulsion storage stability of soy protein isolate

Abstract This study investigated the impact of electrolysis modification on the structural characteristics of SPI and used the prepared novel emulsifier to improve the storage stability of the oil-in-water emulsion. The exposed sulfhydryl group content increased from 12.62 × 10−5 mol/g in the control to 14.35 × 10−5 mol/g in the SPI following electrolysis for 120 min. In addition, after electrolysis the secondary structural analysis using Fourier transform infrared spectroscopy (FTIR) indicated that samples showed a decrease in the α-helix proportion, and fluorescence spectra revealed tertiary conformational changes of the SPI. The particle size distributions of the electrolysis-treated protein solutions had monomodal distributions, and the ζ-potential absolute values became larger. The water holding capacity (WHC) and fat holding capacity (FHC) were significantly improved. The peroxide value (POV) of oil in the electrolysis-treated SPI emulsion was 14.59 mmol/kg oil, and the protein carbonyl content was also lower than that in the native protein emulsion after it was stored at 25 °C for 4 weeks. In summary, this study might suggest that an electrochemical reactor could be applied to modify the structural characteristics and functions of proteins in order to obtain the desired products.

Effect of gum arabic on the storage stability and antibacterial ability of β-lactoglobulin stabilized d-limonene emulsion

The objective of this research was to investigate the influence of gum arabic (GA) on the storage stability and antibacterial ability of β-lactoglobulin (β-lg) stabilized d-limonene emulsion at pH4.0 based on electrostatic layer-by-layer deposition. The storage stability of emulsions was characterized by droplet size, zeta-potential and degradation of d-limonene during the storage of 4 weeks at 4 °C, 25 °C and 55 °C. Results showed that GA could significantly enhance the physical stability of emulsions and protect d-limonene from oxidation even at high temperature (55 °C). The antimicrobial activity of bilayer emulsion was compared with pure d-limonene and single-layer emulsion by measuring the minimal inhibitory concentration against the microorganisms tested (E. coli, S. aureus, B. subtilis and S. cerevisiae) and total bacterial, Yeast & Mold account in orange juice. Determination of cell constituents released were proceeded to investigate the antibacterial mechanism of d-limonene emulsion. d-limonene and its emulsions were shown to have different antibacterial effects, which manifested as reducing or completely inhibiting the microbial growth. Bilayer emulsion was confirmed to possess slightly inferior antimicrobial efficiency by MICs comparison than single-layer emulsion, but exerted a long-lasting antimicrobial effect in orange juice during the storage.

Synthesis and properties of polyurethane-acrylate hybrid emulsion via monomer dilution method and emulsification method

Abstract High solid content polyurethane-acrylate (PUA) hybrid emulsions have been sucessfully synthesized by monomer dilution method and emulsification method respectively. The effects of dimethylol propionic acid (DMPA) and emulsifiers (sodium dodecyl sulfate (SDS) and nonyl phenol polyoxyethylene ether (OP-10)) on the structure and the properties of emulsions were investigated. Dimethylol propionic acid and emulsifiers content increase brings about smaller particles. However, the storage stability of emulsions is attributed to the increased level of dimethylol propionic acid and emulsifiers, but the effect is not a complete synergy. The emulsion with 3 wt% DMPA or 2 wt% SDS and OP-10, which revealed the pseudoplastic behavior, showed good water resistance and excellent adhesion performance on poly(vinyl chloride) (PVC) packaging film. These results obtained point to the strong potential in PUA hybrid emulsion synthesis with optimal proportion for DMPA and emulsifiers.

Formation of thymol nanoemulsions with combinations of casein hydrolysates and sucrose stearate

Casein hydrolysates (CHs) have the improved emulsifying activity than caseins, and the emulsion stability can be principally improved by co-adsorbing sucrose stearate (SS). The objective of this work was to fabricate thymol nanoemulsions using the combination of CH and SS. CH produced by 10 min pancreatic hydrolysis was used at 2% and mixed with SS to prepare emulsions by shear homogenization and heating at 90 °C for 20 min. Addition of SS from 0 to 1.0% increased the thymol content in nanoemulsions (d3,2 ≈ 50 nm) from 1 to 3%. Excess SS however increased the emulsion turbidity and instability due to its poor solubility at ambient conditions. Heating improved the solubility of SS, strengthened its hydrophobic interactions with CH, and thus greatly improved the emulsion storage stability and the stability at pH 3.0 and 5.0. Therefore, the combination of CH and SS provides a novel approach to prepare nanoemulsions.