Flaxseed Oil Emulsions Research Articles

Selected Soluble Dietary Fibres as Replacers of Octenyl Succinic Anhydride (OSA) Starch in Spray-Drying Production of Linseed Oil Powders Applied to Apple Juice

The aim of the study was to compare two kinds of soluble dietary fibres in a mixture with OSA-starch as wall components of linseed oil capsules. Comparison was made based on emulsion (droplet size, polydispersity index, and viscosity) and powder properties (outer structure, colour, surface oil content, and encapsulation efficiency). Additionally, linseed oil powders were applied to the food model (apple juice) and the colour, physical stability, and volatile compound profile of fortified juice were determined. Although the obtained linseed oil emulsions with different compositions of polysaccharide components showed some variation in droplet size, polydisperse index and viscosity, their encapsulation efficiency by spray-drying was very high (>98%). The powders produced had a similar structure and low surface oil content, and their 2% addition to apple juice did not change its stability and only slightly decreased its colour lightness and yellowness. However, greater differences in the volatile compounds of obtained juices were observed. Overall, the added powders reduced the volatility of aroma compounds typical of apple juice but introduced propanal and hexanal, especially the powders with the highest OSA-starch share.

Tailoring starch-lipid complexes for optimized flaxseed oil emulsion stability, antioxidation, and digestion kinetics

Whereas starch-lipid complex emulsifiers are anticipated to possess both an outstanding amphiphilicity and slowly-digesting characteristics, yet a more sustainable and cost-effective approach remains to be explored. Herein, we systematically prepared starch-lauric acid complexes (SLACs) through a solid encapsulation method under varying reaction temperatures (50–90 °C) and times (0.25–60 h). Complexing index analysis, differential scanning calorimetry, and X-ray diffraction analysis revealed an enhanced degree of complexation in SLACs with prolonged reaction time, evidenced by the inward migration of free lauric acid, as further confirmed by confocal laser scanning microscopy. In vitro digestibility, contact angle, and interfacial tension measurements demonstrated that SLACs exhibited high levels of slowly digestible starch, a low digestion rate, and excellent amphiphilicity, which was particularly notable in SLACs produced at 80 °C for 6 h. Emulsions stabilized by SLACs showed a smaller droplet size, a higher oil loading rate, an increased yield stress, and an improved storage stability compared to V-type starch. Oxidation experiments indicated that SLACs enhanced the oxidative stability of flaxseed oil, with elevated initial oxidation temperatures and reduced levels of oxidative products. In a simulated gastrointestinal digestion model, SLACs-stabilized structured emulsions exhibited sustained release and lower final contents of fatty acids, suggesting superior resistance to bile acids and digestive enzymes compared to PG2000, a chemically modified food starch (i.e. OSA-starch) refined from waxy maize. Our findings provide an effective strategy for enhancing lipid antioxidation and regulating intestinal digestion.

Role of polyphenols conjugation to glycated myofibrillar protein in manipulating the emulsifying behaviors of flaxseed oil emulsion

The unsaturated nature of flaxseed oil renders it susceptible to oxidation during storage. Glycated myofibrillar protein (MP)-polyphenol conjugates were used to improve the emulsifying characteristics of MP-flaxseed oil emulsion. The role of polyphenols, namely, (−)-epigallocatechin-3-gallate (EGCG), catechin (C) and gallic acid (GA), conjugated to MP-dextran (DX) covalent complex on emulsifying properties, stability characteristics and interfacial behavior of MP-flaxseed oil emulsion was investigated. MP-DX-polyphenol covalent complexes were more effective in decreasing creaming index within 24 h while increasing apparent viscosity, oxidation stability and forming more uniform emulsion. Furthermore, the concentration of interfacial proteins around oil droplets increased with polyphenols conjugation (from 3.78 to 9.52 mg/m2), especially with conjugation by EGCG (9.52 mg/m2), thereby contributing to an enhancement in flaxseed emulsion stability. Glycated MP-polyphenol conjugate was a promising emulsion stabilizer to effectively increase emulsion characteristics of flaxseed emulsion.

Multi-scenario application of chitosan emulsions as fat replacers: Based on the regulation of chitosan hydrophobicity and emulsion rheological properties

Excessive intake of saturated fatty acids poses a serious health risk, necessitating the urgent development of healthier plant-based fat replacers. Despite the emulsifying properties of chitosan (CS), it remains a significant challenge to create CS emulsions with minimal CS content and superior rheological properties as fat replacers. In this study, a supramolecular interaction system was constructed with inner hydrophilicity and outer hydrophobicity, enabling tunable rheological properties. This system was utilized to assemble hydrophobically modified CS with sodium alginate through appropriate treatment. As the oil phase fraction in the emulsion of stabilized flaxseed oil in the supramolecular system increases, the viscosity, storage modulus (G′), and loss modulus (G″) of the emulsion also increase. The emulsion transitions to a semi-solid state when the oil phase fraction ≥60 wt%. The supramolecular system (1 mg/g) can stabilize flaxseed oil emulsion with 80 wt% oil phase fraction. There were no significant changes in the morphology and rheological properties of the emulsions following a 60-day storage period at room temperature. In addition, emulsions can be used in several scenarios as fat replacers in food processing due to their tunable rheological properties.

Effect of heat-treated flaxseed lignan macromolecules on the interfacial properties and physicochemical stability of α-linolenic acid-enriched O/W emulsions.

Flaxseed lignan macromolecules (FLMs) are important polyphenols present in flaxseeds with interfacial adsorption behavior. However, FLMs are easily degraded during thermal treatment in emulsions, which further influences their interfacial properties and application. In this work, the interfacial properties of FLMs between oil and water were evaluated using compression isotherms and interfacial tension to investigate the regulation mechanism of FLMs and their heat-treated products on the stability of O/W emulsions. Furthermore, the improvement mechanism of FLM heat-treated products on the physicochemical stability of flaxseed oil emulsions was clarified. Studies showed that thermal degradation occurred on terminal phenolic acids in FLMs when treated under 100 and 150 °C (FLM-100 and FLM-150) without any decrease in antioxidant activity. FLM-100 and FLM-150 improved the physicochemical stability of sunflower lecithin (S90)-stabilized flaxseed oil emulsions and reduced the concentration of hydroperoxides and TBARS by 26.7% and 80% (p < 0.05), respectively, during storage. This was due to the high interfacial anchoring of FLM-100 and FLM-150, which further strengthened the interface of oil droplets and improved the interfacial antioxidant effect of FLMs. This implies that FLM-100 and FLM-150 could act as new efficient antioxidants for application in food emulsions.

Alternative locust control with a dilutable linseed oil emulsion

AbstractLocust swarm control is still a main topic in agriculture and is often based on the extensive use of chemical agents that can be problematic for the environment and human health. Currently, only a few alternative control agents are available on the market, such as neem oil, the fungus Metarhizium sp., and the microsporidian Paranosema locustae. In this study, we improved the formulation of a botanical insecticide that is based on linseed oil and was found to be effective against the desert locust, Schistocerca gregaria. To make sure that linseed oil is most effective, we first tested several natural plant oils in a comparative laboratory study. Linseed oil performed best and resulted in 100% mortality within only 2 days after a single spray treatment. However, this linseed oil formulation contains three expensive essential oils, thus we further improved it to avoid costly essential oils. A much lower concentration of linseed oil was also found to be highly effective and killed adult S. gregaria within 3 days in an experiment performed under semifield conditions. Furthermore, a concentrated stock solution of this botanical insecticide was developed to increase stability and reduce shipping costs in areas where water for dilution is available. Mechanical treatment, applied during the preparation of this linseed oil emulsion, resulted in the formation of micro‐colloids, which prevent the separation of phases and enable 1:16 dilution with water containing bicarbonate. Interestingly, only 24 h after single spray treatment, locusts became immobile and most of them were unable to jump, which would make them easy prey for natural enemies. Later, insects died due to the hardening of the linseed oil emulsion. This novel linseed oil emulsion is harmless for humans, rather easy to produce, and remains stable over weeks in its concentrated form, which suggests that it is promising alternative agent for locust control.

Product diversification to boost the sustainability of the shrimp processing industry: The case of shrimp-waste driven chitosan-based food Pickering emulsion stabilizers

Diversifying the product portfolio of the shrimp processing industry using its waste streams could contribute to its environmental sustainability and economic resilience. Considering that this study aimed to increase the commercial value of shrimp shell waste by using chitosan extracted from these wastes as a food emulsion stabilizer. More specifically, chitin was extracted from shrimp shell waste, and chitosan was then prepared from chitin by deacetylation. The findings showed that the extraction efficiency and degree of deacetylation of chitosan were 23% and 83%, respectively. After that, stearic acid was added to chitosan chains to improve its emulsifying properties. Then, the chitosan/stearic acid–stabilized flaxseed oil and olive oil emulsions were prepared in three oil ratios (20, 40 and 60%). The interfacial structure study showed that compared to flaxseed oil droplets, the olive oil droplets’ surface was better covered with the chitosan/stearic acid nanogels. Moreover, the rheological study indicated a stronger gel-like structure in olive oil emulsions than the flaxseed oil emulsions, particularly at 60% oil. The dried emulsions indicated that the olive oil was encapsulated better than flaxseed oil by the chitosan-based particles, and less oil leakage was observed for dried olive oil emulsions. Better encapsulation of olive oil with chitosan/stearic acid nanogels could be attributed to the higher polarity and viscosity of olive oil compared to flaxseed oil and the greater similarity of olive oil fatty acid profile with stearic acid attached to chitosan. In general, these findings showed that the stabilizer developed from shrimp shell waste is suitable for stabilizing emulsions containing more polar oils with less degree of unsaturation. The results obtained could contribute to enhancing the sustainability of the shrimp processing industry by diversifying its product portfolio.

Development of meat spread with omega-3 fatty acids derived from flaxseed oil for the elderly: Physicochemical, textural, and rheological properties

This study evaluates the characteristics of n-3-enriched meat spread that is in development for consumption by elderly individuals. Herein, flaxseed oil was used as a source of n-3 fatty acid, and macro- and nano-sized flaxseed oil emulsions (FOE) were prepared for the fabrication of meat spreads. As the level of FOE was increased in the meat spreads, significant increases in the levels of omega-3 fatty acids (α-linolenic acid) were observed. Emulsion stability and cooking loss were also improved in meat spreads formulated with FOE compared with those the control. In particular, the addition of FOE generated softer and less chewy meat, owing to its lower melting point and rheological properties. However, the high content of unsaturated fatty acids in the FOE-containing meat spreads increased their susceptibility to lipid oxidation meat. These findings indicate that FOE, particularly macro-sized FOE, has the potential for use in n-3 fatty acid enriched meat products that are intended for consumption by elderly individuals but need to be evaluated for their impacts on shelf-life and sensory quality.

The Influence of Oil Concentration on the Rheological Properties of Flaxseed Oil Emulsion Stabilized by Pregelatinized Waxy Rice Starch

The Influence of Oil Concentration on the Rheological Properties of Flaxseed Oil Emulsion Stabilized by Pregelatinized Waxy Rice Starch

Impact of Phenolic Acid Derivatives on the Oxidative Stability of β-Lactoglobulin-Stabilized Emulsions.

Proteins, such as β-lactoglobulin (β-Lg), are often used to stabilize oil-water-emulsions. By using an additional implementation of phenolic compounds (PC) that might interact with the proteins, the oxidative stability can be further improved. Whether PC have a certain pro-oxidant effect on oxidation processes, while interacting non-covalently (pH-6) or covalently (pH.9) with the interfacial protein-film, is not known. This study aimed to characterize the impact of phenolic acid derivatives (PCDs) on the antioxidant efficacy of the interfacial β-Lg-film, depending on their structural properties and pH-value. Electron paramagnetic resonance (EPR) analyses were performed to assess the radical scavenging in the aqueous and oil phases of the emulsion, and the complexation of transition metals: these are well known to act as pro-oxidants. Finally, in a model linseed oil emulsion, lipid oxidation products were analyzed over storage time in order to characterize the antioxidant efficacy of the interfacial protein-film. The results showed that, at pH.6, PCDs can scavenge hydrophilic radicals and partially scavenge hydrophobic radicals, as well as reduce transition metals. As expected, transition metals are complexed to only a slight degree, leading to an increased lipid oxidation through non-complexed reduced transition metals. At pH.9, there is a strong complexation between PCDs and the transition metals and, therefore, a decreased ability to reduce the transition metals; these do not promote lipid oxidation in the emulsion anymore.

Effect of Beef Fat Replacement with Linseed Oil Emulsions on Physicochemical and Sensory Properties of Beef Patties

Effect of Beef Fat Replacement with Linseed Oil Emulsions on Physicochemical and Sensory Properties of Beef Patties

Exploration of suitable in vitro simulated digestion model for lipid oxidation of flaxseed oil emulsion during digestion.

The INFOGEST model is a standardized general in vitro digestion study, but it cannot accurately simulate the fatty acid release process of lipids in the stomach and small intestine. In this study, the internationally universal INFOGEST 2019 was used as the basic model and flaxseed oil emulsion was used as the research object. In various improvement models, the effect of fatty acid release rate on the oxidation stability of flaxseed oil was assessed by adding rabbit stomach extract and changing the order of bile salts addition. With the presence of rabbit gastric extract, flaxseed oil emulsion flocculation and coalescence in stomach were reduced, and the absolute value of ζ-potential increased. Moreover, the release rate of fatty acids in the small intestine increased by 12.14%. The amount of lipid oxidation product (i.e. hexanal) in the gastric and intestinal phases increased by 0.08 ppb. In addition, the fatty acid release rate in the small intestine phase increased by 5.85% and the hexanal content increased by 0.011 ppb in the digestion model of adding bile salts before adjusting the pH in the small intestine phase compared with the model of adjusting the pH first and then adding bile salts. The results obtained from this study will contribute to finding the most suitable static digestion model for simulating digestion and oxidation of lipid during lipid gastrointestinal digestion. © 2022 Society of Chemical Industry.

Optimized endogenous lipid concomitants in flaxseed oil by different oil extraction technologies: Their positive roles in emulsions

In this study, different oil extraction technologies were used to obtain flaxseed oil with different lipid concomitants, and the influences of endogenous lipid concomitants on the stability and digestion properties of flaxseed oil emulsions were investigated. Compared with cold-press (CP), microwave pretreatment coupled with cold-press (MPCP) and accelerated solvent extraction (ASE) contributed to the accumulation of hydrophilic and lipophilic lipid concomitants, respectively. Subcritical fluid extraction (SFE) and supercritical CO2 extraction (SCO2E) were conducive to the accumulation of amphipathic lipid concomitants. After emulsification, ASE-flaxseed oil emulsions had the lowest initial particle size due to the high content of amphiphilic lipid concomitants phospholipids. Phospholipids are spontaneously adsorbed on the interface of flaxseed oil and water. Antioxidative lipid concomitants (phenols, phytosterols, carotenoids, flavonoids, and cyclolinopeptides (CLs)) in MPCP-flaxseed oil improved the oxidative stability of emulsions. After digestion, ASE-flaxseed oil emulsion presented the highest FFAs% (∼78%) owing to smaller particle size. The release of FFAs decreased by 5%–10% in MPCP-, SCO2E-, and SFE-flaxseed oil emulsions ascribed to the high content of phenols. In conclusion, MPCP and ASE are powerful flaxseed oil extraction technologies for improving the stability and digestion of emulsions, respectively.

Temporal changes in the physicochemical, textural and sensory attributes of butter fortified with vegetarian source of omega-3 fatty acid

Fortification of butter with omega-3 fatty acids and alpha linolenic acid results in higher level of unsaturated fatty acids. This may affect the oxidative stability of butter. Therefore, the present study was conducted to evaluate the impact of storage on the physico-chemical, textural and sensory attributes of the fortified butter samples packed in polypropylene cups and stored at 5 and -18 °C. The samples were analysed for 90 days with an interval of 15 days. During the storage, the samples were analysed for physico-chemical properties, oxidative stability, textural characteristics, sensory characteristics and microbial quality. Control sample showed higher (4.35 h) induction period than samples prepared by adding flaxseed oil (2.36 h) and flaxseed oil emulsion (2.56 h) as studied by rancimat. Peroxide value, free fatty acids and TBA value increased significantly (P<0.05) during storage however, the values were within the acceptable range. The optimized butter samples were examined for storage stability under refrigeration and frozen conditions for 90 days. Firmness, work of shear and yield stress increased slightly during the storage and samples stored at -18oC showed higher values than refrigerated storage. Even though, overall sensory acceptability decreased significantly (P<0.05) during the storage and the samples stored at -18oC showed higher score than refrigerated storage; it was still above 7.5 on 9 point hedonic scale. No microbial growth was observed throughout the storage period. Thus, it is concluded that omega-3 fatty acid fortification doesn’t adversely affect the storage stability of fortified butter and the butter has good sensorial acceptability and oxidative stability for 90 days of storage period.

The physicochemical properties and stability of flaxseed oil emulsions: effects of emulsification methods and the ratio of soybean protein isolate to soy lecithin.

The properties and stability of emulsion rely greatly on the emulsification method and emulsifier. In this study, different emulsification methods (high-speed homogenization, ultrasonic treatment and their combination) were employed for the preparation of emulsions stabilized by soybean protein isolate (SPI) and soy lecithin (SLT) at three ratios. The microstructure, hydrodynamic average diameter, ζ-potential, creaming stability and low-field nuclear magnetic resonance relaxation behaviors of emulsions were investigated. The results indicated that the influence of emulsification method was closely related to the ratio of SPI/SLT. Overall, the SPI-SLT-stabilized emulsion treated by ultrasound showed better stability and uniformity, while the combined treatment of high-speed homogenization and ultrasound was helpful in improving the uniformity and stability of SPI-stabilized Pickering emulsion. However, the SLT-stabilized emulsions all exhibited worse uniformity in terms of particle size distribution and polydispersity index. These results will be helpful for selecting an appropriate emulsification method and emulsifier to improve the stability of emulsions. © 2021 Society of Chemical Industry.

Effect of different structural flaxseed lignans on the stability of flaxseed oil-in-water emulsion: An interfacial perspective

The influences of the different structural flaxseed lignans on flaxseed oil (FO) emulsions during storage and digestion were investigated, focusing on their interfacial behavior. From perspective of interface, more than 60% of secoisolariciresinol (SECO) and the acidic hydrolysates of flaxseed lignan macromolecule (FLEH) were located on the interface of FO emulsions. It improved the stability of FO emulsions both during storage and digestion by inhibiting of free radical penetration and improving their targeted antioxidative activity. By comparison, the secoisolariciresinol diglucoside (SDG) and the alkaline hydrolysates of flaxseed lignan macromolecule (FLE) largely located in the aqueous and exerted lower antioxidative efficiency in emulsions. Moreover, SDG, SECO, FLE and FLEH slowed down the digestive rate of FO in emulsions, which might be due to flaxseed lignans inhibited the activity of digestive enzymes. These findings suggested that the different structural flaxseed lignans had the potential as antioxidants in emulsions during storage and digestion.

Low‐Field Nuclear Magnetic Resonance Time Domain Characterization of Polyunsaturated Fatty Acid–Rich Linseed and Fish Oil Emulsions during Thermal Air Oxidation

AbstractLinseed contains high levels of polyunsaturated fatty acids (PUFA), such as α‐linolenic acid (&gt; 50% ALA‐18:3), that are naturally protected against thermal oxidation by their encapsulation within linseed oil bodies (OB) by multiple components including antioxidant proteins and mucilage emulsifying agents. Linseed OB emulsions (LSE) can be produced by grinding linseed seeds, adding water, adjusting pH, and sonication. This is a process that can encapsulate externally added PUFA to minimize their thermal oxidation, as it does for the intrinsic ALA PUFA. Fish oil (FO) encapsulation into this LSE platform to form linseed fish oil emulsions (LSFE) offers the possibility of a nutritive delivery system of the biologically essential FO PUFA eicosapentaenoic acid and docosahexaenoic acid. In this study, 1H low‐field nuclear magnetic resonance (LF‐NMR) is used to characterize LSE's and LSFE's chemical and structural properties as well as their stability and changes under thermal oxidation (55 °C for 96 hours). 1H LF‐NMR data processing was developed to generate one‐dimensional (1D) T1 (spin–lattice), 1D T2 (spin–spin), and 2D (T1 vs. T2) relaxation time spectra that can characterize OB emulsions and monitor their time domain fingerprints (spectrum peaks) of chemical and structural changes during the oxidation process. The 1H LF‐NMR analysis were further supported and correlated with conventional peroxide value test, self‐diffusion, droplet size distribution, zeta potential estimation of surface stability, and gas chromatography–mass spectrometry analysis of fatty acid profile changes under thermal oxidation conditions. The 1D and 2D LF‐NMR relaxation spectra showed that the LSE and LSFE did not suffer intense oxidation process, due to PUFA assembly in OB oxidative protection. These results were further confirmed by the supportive analytical methodologies. The results of this study demonstrate the efficacy of 1H LF‐NMR methodology to monitor PUFA's rich oil and emulsion thermal oxidation.

Application of Caseinate Modified with Maillard Reaction for Improving Physicochemical Properties of High Load Flaxseed Oil Microcapsules

AbstractHigh‐load flaxseed oil microcapsule is prepared with the Maillard reaction products (MRPs) of sodium caseinate and isomaltooligosaccharide as wall material. It is found that the emulsifying activity index and emulsion stability index of MRPs are increased by 31.32% and 34.11% respectively at the appropriate degree of graft (26.30%) compared with the mixture of sodium caseinate and isomaltooligosaccharide. Smaller droplet size and lower polydispersity index can be achieved in the flaxseed oil emulsions coated by MRPs, due to the change of sodium caseinate molecular weight and spatial structure. The microencapsulation efficiency of the microcapsules coated by MRPs is highly improved up to 98.22% at oil load of 58.43%, compared with the control group. Furthermore, MRPs as coating material can protect flaxseed oil against lipid oxidation at 50 °C for 4 weeks. More importantly, the smooth, round, and compact external surface structures of microcapsule powder support its physical necessity for industrial usage. Due to its high microencapsulation efficiency and good oxidation stability, MRPs formed with sodium caseinate and isomaltooligosaccharide show great application potential in preparing high load oil microcapsule.Practical Applications: Findings in this research could be utilized for developing microencapsulation loaded with higher concentration of flaxseed oil, a rich source of α‐linoleic acid and lignans. Application of MRPs (Maillard reaction products) formed through interaction between sodium caseinate and isomaltooligosaccharide by heating improved both its physicochemical properties and oxidative stability. It is a novel approach for developing microcapsule with higher percentages of oils with better oxidative stability.

Peanut and linseed oil emulsion gels as potential fat replacer in emulsified sausages

The study aimed to highlight the utilization of gelled emulsion (GE) systems containing peanut and linseed oils to replace beef fat partially or completely in emulsified sausages. Total fat content was reduced by up to 40% and energy content was lowered by up to 27% in reformulated products. Saturated fatty acids and cholesterol were successfully decreased while noticeable increments were provided in mono and poly-unsaturated fatty acids in sausages containing GE. Moreover, the reformulation procedure presented a good potential for increasing n-3 content, while lowering atherogenicity index, thrombogenicity index, and n-6/n-3 ratios. Although the incorporated GE resulted in color and texture alterations, it was effective to improve the technological attributes in terms of emulsion stability and cooking behaviors. In GE added samples, oxidative stability of final products decreased; however sensory features were acceptable. Overall results pointed out that GE systems could be successfully conveyed to emulsified sausage formulations to ensure a healthier lipid profile with good technological and sensory quality.

Ultrasonic assisted oil-in-water emulsions stabilized by flaxseed protein isolate: influence of different oils

In this study, the physicochemical properties and stability of ultrasonic assisted flaxseed protein isolates (FPI) emulsions containing medium chain triglycerides (MCT), soybean oil, flaxseed oil, or docosahexaenoic acid (DHA) algae oil were investigated. The particle size distribution, zeta-potential, turbiscan stability index (TSI), and backscattering profiles were determined. The results showed that the emulsions containing flaxseed oil had the smallest droplet size and the lowest TSI value after 30 min ultrasonic treatment. Flaxseed oil emulsions showed the best storage stability with minimum clarified layer and cream layer after 10 days storage. MCT emulsions were more sensitive to salt, and less stable than other oil emulsions. Soybean oil, flaxseed oil, and DHA oil emulsions had good stability under low ionic strengths (0–50 mM NaCl), and became unstable under high ionic strengths (150 and 300 mM). Thermal treatment had great influence on the particle size distribution of emulsions. The particle size of the four oils emulsions increased after heating at 90 °C for 30 min. However, the particle size of DHA oil and flaxseed oil emulsions decreased after heating at 50 °C for 30 min. In conclusion, ultrasonic treatment is one of the effective ways to improve stability of FPI-stabilized emulsions, which are based on the oil type and ultrasound intensity. The effects of oil type and chain length on particle size and stability of FPI-stabilized emulsions could be further studied.