Improved Emulsion Stability Research Articles

Effect of Medium-High Energy Emulsification Condition on Physicochemical Properties of β-Sitosterol Multiple Emulsion

Phytosterols are used to lower the blood cholesterol. β-Sitosterol is one of the most important phytosterols with very poor water solubility and bioaccessibility. The main goal of the current research was to investigate the effects of different emulsification variables (i.e. shear, time, pressure and cycle) on the physicochemical properties, release behaviour and encapsulation efficiency of β-sitosterol in water-in-oil-in water (W/O/W) emulsion. Initially, 19 β-sitosterol emulsions were prepared under different experimental conditions (shear 3000 and 6000 rpm; time 2.5 and 5 min; pressure 100, 200 and 300 bar; cycle 1–3). In this study, the β-sitosterol emulsion prepared at 6000 rpm, 5 min, 300 bar and 3 cycles had the smallest average droplet size (139 nm) among all prepared samples. The interaction between shear and time showed the most significant (P < 0.05) effect on the polydispersity index (PDI) and turbidity of the β-sitosterol emulsion. Increasing homogenization pressure and cycle led to improving emulsion stability and encapsulation efficiency. The β-sitosterol emulsion homogenised at 100 bar for 1 cycle had the highest encapsulation efficiency (81.7%) among all samples. The optimization study showed that the emulsification at 300 bar for 3 cycles resulted in the most desirable β-sitosterol emulsion.

Effects of soluble soy polysaccharides and gum arabic on the interfacial shear rheology of soy β-conglycinin at the air/water and oil/water interfaces

In this study, the effects of soluble soy polysaccharides (SSPS) and gum arabic (GA) on the interfacial shear rheological properties of β-conglycinin (7S) at both the air/water and oil/water interfaces were investigated. The results showed that the adsorption behavior at the two interfaces were quite different. For 7S–SSPS, the adsorption behavior was mainly dominated by 7S, with a lower adsorption rate than that for 7S alone at the air/water interface. Conversely, the adsorption behavior was mainly dominated by SSPS at low adsorption times but was later dominated by 7S adsorption at the oil/water interface. Emulsion stability measurement showed that the 7S-based emulsion was stabilized against flocculation by SSPS even under acidic conditions, which might be attributed to the bounded SSPS molecule stabilized the oil droplets effectively by steric stabilization. Addition of GA did not improve emulsion stability under acidic conditions because GA dominated the adsorption layer and did not provide steric stabilization at the oil/water interface. Surprisingly, with or without polysaccharides, 7S could form an interfacial film with a high elastic modulus under all conditions, even near the isoelectric point, which indicated that flocculation might be mainly due to the electrostatic attraction between the emulsion droplets. The results of this study suggested that stability of oil/water emulsions could be achieved through the formation of a protein-dominated interfacial film surrounded by polysaccharides that provided steric stabilization.

Effect of different treatments on the microstructure and functional and pasting properties of pigeon pea (Cajanus cajan L.), dolichos bean (Dolichos lablab L.) and jack bean (Canavalia ensiformis) flours from the north‐east Argentina

SummaryThe effect of germination (G; 5 days), soaking‐cooking (SC; 6 h–20 min, 6 h–40 min, 6 h–60 min) and microwave (M; 50%, 70%, 100%) treatments on pigeon pea (PP), dolichos bean (DB) and jack bean (JB) seeds was studied. Microstructure of seeds and functional (protein solubility, water‐holding capacity, oil‐holding capacity, emulsion stability) and pasting properties of flours were determined. Germination and microwave treatments modified the protein matrix of cotyledon cells preserving the shape of the starch granule, whereas the SC treatment (6 h–60 min) affected both. The soaking‐cooking is the most influential treatment on the functional properties of PP, DB and JB flours, as increased water absorption capacity (73–96%), decreased protein solubility (&gt;80%) and the tendency to retrogradation of amylose (69–85%) also improved emulsion stability.

Enzymatic modification of egg lecithin to improve properties.

This research studied the enzymatic modification of egg yolk phospholipids and its effect on physicochemical properties. Egg yolk lipids were extracted with food grade ethanol and egg phospholipids (ePL) produced by deoiling with acetone. Vegetable oils were used to interesterify ePL utilizing Lipozyme®: sn-1,3 specific lipase. The enzymatic interesterification resulted in a single phase liquid product, whereas simple blending of the ePL and vegetable oil resulted in a product with two phases. In addition solid fat content decreased by 50% at -10°C and 94% at 35°C when compared with egg yolk lipids extract. A decrease in melting temperature resulted from the interesterification process. Interesterification improved emulsion stability index when used as an emulsifier in oil-in-water emulsion and compared to the native and soy lecithin. Enzyme reusability test showed retention of 63% activity after 10 cycles. Overall, the properties of native egg phospholipids were significantly enhanced in a potentially useful manner through interesterification.

Properties and oxidative stability of emulsions prepared with myofibrillar protein and lard diacylglycerols

The objective of this study was to investigate the emulsifying properties and oxidative stability of emulsions prepared with porcine myofibrillar proteins (MPs) and different lipids, including lard, glycerolized lard (GL) and purified glycerolized lard (PGL). The GL and PGL emulsions had significantly higher emulsifying activity indices and emulsion stability indices than the lard emulsion (P<0.05). The PGL emulsion presented smaller droplet sizes, thus decreasing particle aggregation and improving emulsion stability. The static and dynamic rheological observations of the emulsions showed that the emulsions had pseudo-plastic behavior, and the PGL emulsion presented a larger viscosity and a higher storage modulus (G′) and loss modulus (G′′) compared with the other two emulsions (P<0.05). The formation of thiobarbituric acid-reactive substances, carbonyl contents and total sulfhydryl contents was not significantly different between the emulsions with PGL, GL and lard (P<0.05). In general, lard diacylglycerols enhanced emulsifying abilities and had no adverse effects on the oxidation stability of the emulsions prepared with MPs.

Surface modification of zein colloidal particles with sodium caseinate to stabilize oil-in-water pickering emulsion

Zein colloidal nanoparticles can adsorb at the oil–water interface to form Pickering emulsion. However, zein Pickering emulsion is usually not stable due to the poor wettability of zein colloidal nanoparticles. The objective of this study was to modify the surface of zein nanoparticles using sodium caseinate (NaCas) and assess the properties of zein/NaCas nanocomplexes and the resultant oil-in-water Pickering emulsions. One percent (w/w) of zein/NaCas colloidal nanocomplexes were formed, with the zein:NaCas ratios (w/w) ranging from 10:1 to 10:4 at pH = 3 by an ultrasound treatment. The zeta-potential of the zein/NaCas nanocomplexes showed altered surface charges, indicating that NaCas adsorbed on the surface of the zein colloidal nanoparticles. Three-phase contact angle measurements suggested that the original zein colloidal nanoparticles were preferentially wetted in water. The incorporation of 0.1%–0.2% (w/w) NaCas significantly enhanced its wettability in the oil, and intermediate wettability was achieved at a zein:NaCas ratio of 10:3. Confocal laser scanning microscope (CLSM) images showed that the incorporation of NaCas improved the interfacial coverage of the Pickering emulsions. When the zein:NaCas ratio ranged from 10:1 to 10:3, the interface was composed of zein/NaCas nanocomplexes. At a zein:NaCas ratio of 10:4, NaCas can competitively adsorbed to the interface and formed a hybrid interfacial structure. The Zein/NaCas nanocomplexes stabilized the Pickering emulsions and exhibited greater centrifugal stability than plain zein emulsions at most pHs and ionic strengths. The underlying mechanisms of the improved emulsion stability are discussed in this paper. This study explored a novel approach to stabilizing Pickering emulsions via the surface modification method using a food-grade protein.

Utilization of proteins from AluProt‐CGNA (a novel protein‐rich lupin variety) in the development of oil‐in‐water multilayer emulsion systems

The formation of multilayered interfaces around oil droplets in oil‐in‐water (O/W) emulsions provides a novel means of improving the quality and stability of many food products. In this work, a system of O/W emulsions containing lipid droplets stabilized by different ionic biopolymers was developed, and their stability under different environmental stresses was evaluated. The protein isolate from a new lupin variety (AluProt‐CGNA) and two polysaccharides—chitosan and xanthan gum—were utilized. AluProt‐CGNA protein‐stabilized emulsions were unstable to aggregation at pH values around their isoelectric point (pI 4.6) and to all the temperatures and salt concentrations evaluated in this study. However, in the presence of chitosan (0.06 wt%), the droplets showed good stability to aggregation from pH 3 to 6, at 30–90°C and at ≤100 mM NaCl. Adding xanthan gum (0.1 wt%) to the system improved emulsion stability from pH 4 to 7, where no phase separation was observed. This study showed that the stability of O/W emulsions containing protein (AluProt‐CGNA)‐coated lipid droplets under environmental stresses can be improved by adding certain concentrations of chitosan and xanthan gum. These findings have important implications for the design of encapsulation and delivery systems for lipophilic compounds in the food industries.Practical applications: The development of multilayer emulsions can be extremely useful to the encapsulation of lipophilic bioactive molecules for food applications, such as polyunsaturated fatty acids (PUFAs), flavors, vitamins, etc. Moreover, this technique provides a system for the creation of O/W emulsions with improved stability to environmental stresses, protection of oil phase, and controlled and triggered release of microencapsulated compounds. In this work, the design of stable O/W emulsions containing PUFAs rich oil droplets surrounded by multiple layer interfacial membranes from food grade ingredients, such as lupin proteins (AluProt‐CGNA), chitosan, and xanthan gum membranes; has been performed. The designed emulsion proved to be stable under different environmental stresses found in many food products. Moreover, thermal stability exhibited by these emulsions could also be an important characteristic for its use in food products.The diagram shows the formation of multilayer emulsions.

Competitive adsorption and displacement of anionic polysaccharides (fucoidan and gum arabic) on the surface of protein-coated lipid droplets

The electrostatic deposition of polysaccharides on protein-coated lipid droplets can improve emulsion stability and performance. Emulsions often contain a mixture of different polysaccharides, which may compete for attachment to the lipid droplet surfaces. The purpose of this study was to investigate the competitive adsorption and displacement of two anionic polysaccharides with different molecular properties (fucoidan and gum arabic) to caseinate-coated lipid droplets, using a combination of electrophoresis, light scattering, and isothermal titration calorimetry methods. Fucoidan had a higher negative charge, molecular weight, and radius of gyration than gum arabic. Both fucoidan and gum arabic were capable of absorbing to the caseinate-coated lipid droplets due to electrostatic attraction, but fucoidan adsorbed at a higher pH (pH 6) than gum arabic (pH 4.5), and required a lower amount to saturate the droplet surfaces (around 0.03 wt% versus 0.04 wt% for saturating 0.5 wt% emulsion). The ζ-potential of the lipid droplets saturated with polysaccharide was considerably more negative for fucoidan (−40 mV) than for gum arabic (−22 mV). In the presence of a mixture of the two polysaccharides, fucoidan preferentially adsorbed to the droplet surfaces rather than gum arabic. Furthermore, fucoidan rapidly displaced gum arabic from gum arabic-coated lipid droplet surfaces, which promoted droplet aggregation and led to an exothermic enthalpy change. In contrast, gum arabic was unable to displace fucoidan from fucoidan-coated lipid droplets, which was attributed to the higher charge density of the fucoidan. These results have important implications for designing polysaccharide/protein-coated multilayer emulsions for specific applications.

Pea, Chickpea and Lentil Protein Isolates: Physicochemical Characterization and Emulsifying Properties

This work is focused on physicochemical and emulsifying properties of pea (PP), chickpea (CP) and lentil (LP) proteins. We evaluated the molecular weight distributions, surface net charge, free sulfhydryl group (SH) and disulfide bond (SS) contents, protein solubility and thermal stability of the protein isolates. Their emulsifying properties (droplet size distribution, flocculation, coalescence and creaming) were also determined as function of pH values. The three protein isolates exhibit similar physicochemical properties, including good solubility and high thermal stability despite a high degree of denaturation. In addition, we analysed the influence of pH on stability of oil-in-water (O/W; 10 wt%/90 wt%) emulsions stabilized by the legume protein isolates. Concerning emulsifying ability and stability, the most unfavourable results for all three protein isolates relate to their isoelectric point (pI = 4.5). A significant improvement in emulsion stability takes place as the pH value departs from the pI. Overall, this study indicates that pea, chickpea and lentil proteins have great potential as food emulsifiers.

Increased Emulsion Stability for Reverse Y‐Shaped Sugar‐Based Surfactants

AbstractA series of reverse Y‐shaped surfactants containing aromatic and aliphatic linkers to combine two short hydrocarbon chains and one carbohydrate head group was prepared. Liquid crystalline behavior, air–water interfacial properties, and efficiency as an emulsifier was investigated for each reverse Y‐shaped surfactant. All reverse Y‐shaped surfactants mediated higher emulsion stabilities for water‐in‐oil compared to common typical reference surfactants, reflecting an improved ability to cope with a curvature towards water. The introduction of a benzene ring into the linker substantially increased the affinity of the surfactant for hydrophobic media, resulting in improved emulsion stability for both water‐in‐oil and oil‐in‐water.

Improved stability of lipiodol-drug emulsion for transarterial chemoembolisation of hepatocellular carcinoma results in improved pharmacokinetic profile: Proof of concept using idarubicin.

To investigate the relationship between the improved stability of an anticancer drug-lipiodol emulsion and pharmacokinetic (PK) profile for transarterial chemoembolisation (TACE) of hepatocellular carcinoma (HCC). The stability of four doxorubicin- or idarubicin-lipiodol emulsions was evaluated over 7 days. PK and clinical data were recorded after TACE with the most stable emulsion in eight unresectable HCC patients, after institutional review board approval. The most stable emulsion was the one that combined idarubicin and lipiodol (1:2 v:v). At 7 days, the percentages of aqueous, persisting emulsion and oily phases were 50-0-50, 33-0-67, 31-39-30, and 10-90-0 for the doxorubicin-lipiodol (1:1 v:v), doxorubicin-lipiodol (1:2 v:v), idarubicin-lipiodol (1:1 v:v), and the idarubicin-lipiodol (1:2 v:v) emulsion, respectively. After TACE, mean idarubicin Cmax and AUC0-24h were 12.5 ± 9.4 ng/mL and 52 ± 16 ng/mL*h. Within 24 h after injection, 40% of the idarubicin was in the liver, either in vessels, tumours, or hepatocytes. During the 2 months after TACE, no clinical grade >3 adverse events occurred. One complete response, five partial responses, one stabilisation, and one progression were observed at 2 months. This study showed a promising and favourable PK and safety profile for the idarubicin-lipiodol (1:2 v:v) emulsion for TACE. • Transarterial chemoembolisation (TACE) regimens that improve survival in hepatocellular carcinoma are needed. • Improved emulsion stability for TACE resulted in a favourable pharmacokinetic profile. • Preliminary safety and efficacy data for the idarubicin-lipiodol emulsion for TACE were encouraging.

Reducing Animal Fat in Bologna Sausage Using Pre‐Emulsified Linseed Oil: Technological and Sensory Properties

AbstractPre‐emulsified linseed oil with sodium caseinate was used to partially replace pork fat in commercial formulations of bologna sausage. A central composite rotational design was carried out to determine the effects of pork fat content (5–20%) and linseed oil (2.5–12.5%) on the emulsion stability, texture profile, color and sensory acceptance of the products. The fat content above 15% influenced both hardness and chewiness of the products. Only the linear effect of the independent variable linseed oil was significant for L* values (P &lt; 0.05). The formulations containing more than 3.95% linseed oil presented higher a* values, lower b* values and improved emulsion stability. The results obtained for the technological properties corroborate the sensory evaluation, in which the attributes color, aroma and flavor had satisfactory scores for the products containing up to 3.95% linseed oil.Practical ApplicationsBologna sausages are widely consumed in Brazil but traditionally have a high content of saturated fats. Therefore, changing the lipid profile of these products is an alternative to the meat industry to offer healthier products to consumers. In this study, the replacement of pork fat by linseed oil was investigated with the aim of providing a new choice for consumption aimed at meeting the nutritional requirements without affecting the sensory and technological properties.

Influence of Degree of Hydrolysis on the Functional Properties of Cowpea Protein Hydrolysates

The effects of limited enzymatic hydrolysis with pepsin on the functional properties and molecular characteristics of cowpea protein concentrate (CPC) were investigated. Hydrolysates were prepared at degrees of hydrolysis (DH) 5–30%. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis demonstrated that globulin was the major protein component of CPC, and enzymatic breakdown of polypeptides was selective. As a result, significant changes in the functional properties of hydrolysates were noticed as compared to the protein concentrate. Then, cowpea protein hydrolysates (CPHs) showed good water solubility index at pH 7 (>95%) and pH 4.5 (>55%), at DH 20 and 30%, respectively. Oil-holding capacity, emulsifying activity and foaming capacity were also improved by the enzymatic hydrolysis, while proteolysis was detrimental to foam stability and did not improve emulsion stability at DH 10–30%. Therefore, CPHs showed good potential for utilization in food formulations. Practical Applications Cowpea is a good nutritional value and available protein source, which could be used for a large-scale production of protein hydrolysates. Enzymatic hydrolysis of food proteins is mostly used to produce ingredients or supplements in food and beverages. In this regard, functional properties of protein hydrolysates are largely dependent on the degree of hydrolysis (DH), which needs to be controlled to avoid excessive proteolysis that can impair functionality and cause unfavorable effects. Then, functional properties of cowpea protein concentrate hydrolyzed by pepsin at DH 5–30% were investigated. The results showed that solubility and oil-holding capacity were higher at DH 20–30%. Emulsifying activity and foaming capacity were also improved following hydrolysis, while de-decreasing molecular weight of protein was detrimental to foam stability of hydrolysates. In summary, cowpea protein hydrolysates showed adequate functional properties for utilization as food ingredient and the peptides produced could turn out to present some biological activities.

Improvement of emulsifying properties of oat protein isolate–dextran conjugates by glycation

In order to improve the emulsifying properties of oat protein, oat protein isolate (OPI)–dextran (Dex) conjugates were prepared by glycation reaction. Emulsifying properties of emulsions stabilized by native OPI (OPIN), OPI–Dex conjugates (ODC) and heated OPI (OPIH) were characterized by zeta-potential, mean droplet size and microstructure. The results showed that the covalent attachment of OPI and dextran was confirmed by determining degree of graft and SDS–PAGE. OPI–Dex conjugates were capable of forming a finer emulsion, which exhibited smaller average particle size and better storage stability under different homogenization pressures (30, 60, 90MPa) compared with OPIN and OPIH. When assessed in different pH and ionic strength, emulsions stabilized by OPI–Dex conjugates resulted in improved emulsion stability to environmental stresses. Confocal laser scanning microscopy depicted more uniform and smaller oil droplets that had a reduced tendency to coalesce for emulsions prepared with ODC.

Modification of starch octenylsuccinate by β-amylase hydrolysis in order to increase its emulsification properties

The orange oil-in-water (O/W) emulsion stabilized by Octenylsuccinic anhydride (OSA) modified waxy maize starch (OS-starch) was investigated. OS-starch was prepared by combining OSA modification of starch and β-amylase hydrolysis. Emulsion stability, droplet size distribution were studied to evaluate the emulsions, and the structure of OS-starch was analyzed using FT-IR, SEC and 1HNMR spectrum to understand the structure–function relationship. Results showed that with β-amylolysis, the average molecular weight of OS-starch decreased while degree of substitution (DS) and degree of branching (DB) increased. OS-starch prepared by using higher β-amylase concentration displayed a better emulsion stability and emulsions showed low apparent viscosity. But increasing the concentration of OS-starch led to big differences in viscosity, the more viscous of the emulsion, the better stability showed. Therefore, β-amylase can be used to modify the structure of OS-starch to improve emulsion stability.

Influence of freezing temperature and maltodextrin concentration on stability of linseed oil-in-water multilayer emulsions

The effect of maltodextrin (MDX) concentration on the stability of multilayer linseed oil-in-water emulsions before and after freeze–thawing has been studied. Interfacial double-layer emulsions were obtained by performing electrostatic deposition of sodium alginate (SA) onto whey protein isolate (WPI) coated oil droplets at pH 5 (10wt% oil, 1wt% WPI 0.25wt% SA). MDX was also added to emulsions formulation in different concentrations (0–20wt%), and the systems were then stored at two freezing temperatures (−18 and −80°C). Stability of emulsions was studied using droplet size, ζ-potential, as well as microstructure determinations and monitoring backscattering profiles versus time. Non-frozen emulsions showed smaller droplet sizes at higher MDX concentrations thus reducing creaming mechanisms and improving emulsion stability. In the absence of MDX, emulsions were highly unstable after freeze–thawing and destabilized faster at −18°C than at −80°C, which was attributed to the formation of larger ice crystals at slower freezing rates that promoted interfacial membrane disruption leading to extensive droplet coalescence and oiling off. Both systems showed macroscopic phase separation within the first hour of analysis. The addition of MDX greatly improved emulsion stability after freezing, as emulsions showed no phase separation after thawing during one week storage. This behavior was attributed to MDX cryoprotectant effect, that could have considerably reduce the amount of ice formed during freezing, thereby maintaining the integrity of the interfacial WPI–SA bilayer surrounding oil droplets. Our results suggest that 20wt% MDX emulsions were the most stable systems both to creaming destabilization and to freeze–thawing processes.

Influence of surfactant and oil composition on the stability and antibacterial activity of eugenol nanoemulsions

Eugenol (Eu) nanoemulsions were prepared by high-pressure homogenization with two surfactants and varied oil compositions. Their stability and antibacterial activities were further evaluated. The results from dynamic light scattering demonstrated that the stability of bulk Eu emulsions stabilized by sodium dodecylsulfate (SDS) was worse than that by Tween 80 (T80). The improvement of emulsion stability by addition of bean oil (BO) depended on the interfacial surfactants. For SDS-stabilized emulsions, Eu emulsions would become stable with the increasing amount of BO. For T80-stabilized emulsions, the improvement of Eu emulsion stability was noticeably different as reported. With the increment of BO, Eu emulsions became stable first, then unstable and finally stable. The repeat instability occurred in Eu emulsions at 60 wt% BO. The results of antibacterial activity showed that emulsion encapsulation could protect and even enhance the antibacterial activity of Eu. The antibacterial capacity of Eu emulsions was affected by the surfactant type, listed as anionic > nonionic surfactant. Time-kill assay presented that lower BO content in Eu-T80 emulsions, the better effect was obtained on the bacterial inhibition against E. coli.

Emulsion stability, thermo-rheology and quality characteristics of ground pork patties prepared with soy protein isolate and carrageenan.

Plant proteins and polysaccharides are often utilised in ground meat products as meat binders, gelling agents, texture stabilisers or fat substitutes. The aim of this study was to investigate the effects of the incorporation of 57 g kg(-1) soy protein isolate (SPI), 7 g kg(-1) carrageenan (CAR) and SPI/CAR mixture on the quality of ground pork patties. Ground pork patties with individual SPI and CAR or SPI/CAR mixture showed either retained or improved emulsion stability, physicochemical properties and dynamic rheology compared with control samples. Although there were no significant colour differences among treatments, samples with SPI/CAR mixture presented higher texture profile values for hardness and chewiness compared with other treatments (P < 0.05). Patties with additives showed significantly lower cooking loss and better thermal emulsion stability than control samples owing to a lower release rate of water and fat (P < 0.05). Compared with control samples or those with individual SPI and CAR, patties with SPI/CAR mixture formed a smoother and more continuous structure with a more compact protein matrix. The results indicate that a mixture of SPI and CAR can be effectively used as a functional ingredient to improve the quality of ground pork patties.

Effect of Molecular Weight Reduction, Acetylation and Esterification on the Emulsification Properties of Citrus Pectin

Citrus pectin was chemically and thermally modified in order to increase the hydrophobic character of the molecule and its adsorptivity to the oil–water interface. The degree of acetylation and methylesterification was increased and the molecular weight was reduced. The emulsion formation and stabilization properties of these modified pectins were evaluated by surface and interfacial tension measurements and emulsification experiments. For the production of emulsions, a high pressure homogenizer was used. The viscosity ratio between oil and emulsion phase was adjusted by varying the amount of added sucrose. Pectins with a higher degree of methylesterification (DE) decrease the interfacial tension significantly compared to the unmodified pectin. Pectins with increased degree of acetylation (DAc), however, show higher interfacial tension values. In emulsification experiments, pectins with a reduced molecular weight do neither significantly reduce droplet sizes nor improve emulsion stability. Pectins with increased DE or DAc reduce the Sauter mean diameter d3,2 of emulsions significantly and, in case of an DE increase, also show excellent long term stability. Their performance is also superior to sugar beet pectin under comparable experimental conditions.

Emulsification properties of enzymatically treated octenyl‐succinic anhydride starch

Octenyl‐succinic anhydride (OSA)‐modified starch was used as an emulsifier in oil‐in‐water emulsions. Multiple analytical techniques, including size‐exclusion chromatography (SEC), confocal laser scanning microscopy (CLSM), and laser diffraction particle size analysis were used to determine the structure and emulsification properties of OSA‐starch. The results indicated that OSA‐starch with a smaller molar mass exhibited improved emulsification properties than its larger counterparts. Furthermore, samples pretreated by enzymatic modification for 25 min showed the best droplet size distribution, improved emulsion stability, and minimum aggregation. It was also determined that stable emulsions were not formed when the average molar mass of OSA‐starch was too small. The emulsion ability of OSA‐starch enzymatically modified for 35 min was found to be a little inferior than that of OSA‐starch upon enzyme treatment for 25 min.