Effectiveness of encapsulating biopolymers to produce sub-micron emulsions by high energy emulsification techniques

In this study, different emulsifying ingredients were used to produce sub-micron emulsions for encapsulation purposes. Maltodextrin combined with a surface-active biopolymer (modified starch, or whey protein concentrate), or a small molecule surfactant (Tween 20) were used as the continuous phase, while d-limonene was the dispersed phase. Results showed that biopolymers are not efficient ingredients to produce very small emulsion droplets compared with small molecule surfactants because of their slow adsorption kinetics. The main problem with surfactants also is instability of the resulted emulsions due to “depletion and bridging flocculation” caused by free biopolymers and competition between surfactant and surface-active biopolymers. In general, it was not possible to produce a fairly stable microfluidized emulsion with surfactants for encapsulation purposes.     

Relationship between functional properties and aggregation changes of whey protein induced by high pressure microfluidization

Aggregation changes of whey protein induced by high-pressure microfluidization (HPM) treatment have been investigated in relation with their functional properties. Whey protein was treated with HPM under pressure from 40 to 160 MPa. Functional properties (solubility, foaming, and emulsifying properties) of whey protein concentrate (WPC) ultrafiltered from fluid whey were evaluated. The results showed significant modifications in the solubility (30% to 59%) and foaming properties (20% to 65%) of WPC with increasing pressure. However, emulsifying property of WPC treated at different pressures was significantly worse than untreated sample. To better understand the mechanism of the modification by HPM, the HPM-induced aggregation changes were examined using particle size distribution, scanning electron microscopy, and hydrophobicity. It was indicated that HPM induced 2 kinds of aggregation changes on WPC: deaggregation and reaggregation of WPC, which resulted in the changes of functional properties of WPC modified by HPM.     

Encapsulation efficiency and oxidative stability of flaxseed oil microencapsulated by spray drying using different combinations of wall materials

This study aimed at evaluating the potential of maltodextrin combination with different wall materials in the microencapsulation of flaxseed oil by spray drying, in order to maximize encapsulation efficiency and minimize lipid oxidation. Maltodextrin (MD) was mixed with gum Arabic (GA), whey protein concentrate (WPC) or two types of modified starch (Hi-Cap 100^TM and Capsul TA®) at a 25:75 ratio. The feed emulsions used for particle production were characterized for stability, viscosity and droplet size. The best encapsulation efficiency was obtained for MD:Hi-Cap followed by the MD:Capsul combination, while the lowest encapsulation efficiency was obtained for MD:WPC, which also showed poorer emulsion stability. Particles were hollow, with the active material embedded in the wall material matrix, and had no apparent cracks or fissures. During the oxidative stability study, MD:WPC combination was the wall material that best protected the active material against lipid oxidation.     

Emulsification mechanisms and characterizations of cold, gel-like emulsions produced from texturized whey protein concentrate

A novel supercritical fluid extrusion (SCFX) process was used to successfully texturize whey protein concentrate (WPC) into a product with cold-setting gel characteristics that was stable over a wide range of temperature. It was further hypothesized that incorporation of texturized WPC (tWPC) within an aqueous phase could improve emulsion stability and enhance the rheological properties of cold, gel-like emulsions. The emulsifying activity and emulsion stability indices of tWPC and its ability to prevent coalescence of oil-in-water (o/w) emulsions were evaluated and compared with the commercial WPC80. The cold, gel-like emulsions were prepared at different oil fractions (φ = 0.20–0.80) by mixing oil with the 20% (w/w) tWPC dispersion at 25 °C and evaluated using a range of rheological techniques. Microscopic structure of cold, gel-like emulsions was also observed by Confocal Laser Scanning Microscope (CLSM). The results revealed that the tWPC showed excellent emulsifying properties compared to the commercial WPC in slowing down emulsion breaking mechanisms such as creaming and coalescence. Very stable with finely dispersed fat droplets, and homogeneous o/w gel-like emulsions could be produced. Steady shear viscosity and complex viscosity were well correlated using the generalized Cox–Merz rule. Emulsions with higher viscosity and elasticity were obtained by raising the oil fraction. Only 4% (w/w) tWPC was needed to emulsify 80% (w/w) oil with long-term storage stability. The emulsion products showed a higher thermal stability upon heating to 85 °C and could be used as an alternative to concentrated o/w emulsions and in food formulations containing heat-sensitive ingredients.     

Evaluation of Folic Acid Nano-encapsulation by Double Emulsions

In this study, optimization of spray drying for double emulsions containing pectin-whey protein concentrate (WPC) was investigated for nano-encapsulation of folic acid. Five independent variables including pectin and WPC content, dispersed phase content, pH, surfactant type of Span, and polyglycerol polyricinoleate (PGPR) were considered along with encapsulation efficiency (EE) as the main response. The experiment design was performed by a Taguchi approach. Final double emulsions were formulations containing an internal nano/micro-emulsion composed of a water in oil (W/O) system with folic acid present in the water phase, re-emulsified within an aqueous phase of pectin-WPC complexes. The average of folic acid EE was approximately 88.3 % in a range of 82.3 to 95.0 %. The main effect analysis with a Taguchi technique revealed that the dispersed phase content of double emulsions was the most important factor affecting EE (36 %) and surfactant had the minimum influence (5 %). Also, it was revealed that the most important interaction between independent variables in terms of EE was between WPC and dispersed phase content while pectin-pH had the lowest interaction. Finally, optimum conditions were determined as 1.0 % pectin, 4.0 % WPC, and 15 % dispersed phase, pH = 6, with a PGPR nano-emulsion which resulted in 99.0 % EE of folic acid.     

High Pressure Effects on Emulsifying Behavior of Whey Protein Concentrate

Oil-in-water emulsions (0.4 wt% protein, 20 vol%n-tetradecane, pH 7) prepared with solutions of pressure-treated (up to 800 MPa) whey protein concentrate (WPC) as emulsifier give a broader droplet-size distribution than emulsions made with native untreated protein. There was a decrease in emulsifying efficiency with increasing applied pressure and treatment time. In contrast, pressure treatment of corresponding WPC emulsions made with the native protein had little effect on emulsion stability. In the pressure-treated emulsion the protein is probably already conformationally modified so that pressure has little additional effect. However, in solution the native structure of the whey protein is modified by pressure resulting in loss of emulsifying efficiency.     

Production of high-oleic palm oil nanoemulsions by high-shear homogenization (microfluidization)

Nanoemulsions present benefits such as an increase in the bioavailability, solubility and targeted delivery of encapsulated substances, and thus, they are a method of incorporating high nutritional value oils, such as high-oleic palm oil (HOPO). In this work, O/W nanoemulsions were obtained by microfluidization using HOPO (1–20% w/w) in the oily phase along with whey (1–20% w/w), Tween 20 (1:1 w/w ratio) and water in the aqueous phase following a surface response design methodology. The response variables were the average drop size (ADS), the polydispersity index (PDI), the zeta potential (ζ), CIELAB color parameters and viscosities of the fresh nanoemulsions (0 days) and nanoemulsions stored at two temperatures (5 and 19 °C) for 4 days. The ADS, PDI and ζ values varied between 163 and 2268 nm, 0.2 and 1, and − 29.7 and − 47.2 mV, respectively. The viscosity was affected by the storage temperature; after 4 days at 19 °C, it increased almost 6-fold compared to the viscosity of the fresh sample. With regards to the color parameters, significant changes were observed based on the concentrations of HOPO and whey. In addition, the prediction equations only presented errors below 7% for the evaluated variables, with R² values above 0.85. Finally, the influence of whey protein denaturation at 60 °C on the stabilities of the two most stable nanoemulsions, according to the optimization process, was observed.Industrial relevanceAmong its many benefits, nanoencapsulation is characterized by increasing the bioavailability of the encapsulated active compound and by the protection that it grants against environmental and processing effects, as micronutrients (for example vitamins) can be susceptible to chemical, enzymatic and/physical instability prior, during and after the processing of food products that contain. One of the techniques studied in recent decades for obtaining nanoemulsions is microfluidization. Microfluidization is a high-energy method that uses high pressure to force the fluid through microchannels that have a specific configuration, emulsifying the fluid by the combined effects of cavitation, shear and impact, thus showing an excellent emulsifying efficiency. However, in food industries the use of microfluidization is not popular and other kind of high shear homogenization are used. In this work, the development of stable emulsions using microfluidization, calls for the use of other types of materials that can provide emulsifying characteristics, such as whey, a compound that is currently one of the main effluents of dairy processes, depending on the type of product.Obtaining nanoemulsions for encapsulation purposes has been studied in many functional products, but to the best of our knowledge, it has not been reported with high-oleic palm oil. This oil contains approximately 50% saturated, 10% di-unsaturated and 40% monounsaturated fatty acids, with oleic acid in sn-2 position in triacylglycerols. This composition makes palm oil as soluble as olive oil. In addition, high-oleic palm oil (HOPO), in particular, has a high stability because it is an oleic acid-rich oil, which has been introduced to replace trans fats and has presented a healthy alternative to such fats in food formulations and the fried food industry.It is also important to highlight that oleic acid has a range of health benefits, such as a decrease in the total cholesterol, an increase in HDL (high-density lipoprotein) and a decrease in LDL (low-density lipoprotein). Oleic acid also retards the development of heart diseases, promotes the formation of antioxidants in the body and reinforces the integrity of the cell wall. In addition, red palm oil (crude) contributes significant nutritional value because it is rich in β-carotenes, α-tocopherol and tocotorienols, supplying vitamins and provitamins that are important for but not produced by the human body.Finally, this work demonstrates that emulsion drop size does not affect the stability of the nanoemulsion if it formulation is designed. Therefore, the goal of this work was to evaluate the most favorable conditions for the microfluidization, formulation and storage of HOPO nanoemulsions using whey powder to produce stable nanoemulsions.     

Emulsifying Property and Antioxidative Activity of Cuttlefish Skin Gelatin Modified with Oxidized Linoleic Acid and Oxidized Tannic Acid

Cuttlefish skin gelatins modified with oxidized linoleic acid (OLA) and oxidized tannic acid (OTA) were characterized and determined for emulsifying properties and antioxidative activity. Modification of gelatin with 5% OTA increased the total phenolic content and 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity and ferric reducing antioxidant power of gelatin–OTA. Incorporation of OLA into gelatin (OLA-to-free amino group molar ratio of 10:1) increased surface hydrophobicity of gelatin from 17.39 to 32.38 and reduce surface tension at air/water interface of gelatin solution from 53 to 32 mN/m. Gelatin–OLA had the increase in emulsion activity index, compared with gelatin without modification and was capable of producing a fine emulsion (d ₃₂?=?0.79 μm, d ₄₃?=?0.82 μm). Modification of gelatin–OLA complex with OTA at different concentrations (2.5%, 5%, and 10%) increased antioxidative activity but decrease emulsifying properties. However, gelatin–OLA modified with 5% OTA had higher emulsifying properties than the commercial gelatin (bovine gelatin). The presence of an alkyl group and a hydroxyl group in gelatin after modification with OLA and OTA, respectively, was revealed by Fourier transform infrared study. Coincidental decrease in free amino group was also noticeable in modified gelatin. Menhaden oil-in-water emulsion stabilized by gelatin modified with OLA and 5% OTA was more resistant to lipid oxidation and phase separation as evidenced by the lower thiobarbituric acid reactive substances value and smaller oil droplet size, compared with that stabilized by commercial bovine gelatin. Thus, the modification of gelatin by both OLA and OTA was able to improve antioxidative and emulsifying properties of cuttlefish skin gelatin.     

Impact of High Hydrostatic Pressure on the Emulsifying Properties of Whey Protein Isolate–Chitosan Mixtures

The influence of high hydrostatic pressure (HHP) on the emulsifying properties of whey protein isolate (WPI) and chitosan mixtures in sunflower oil-in-water emulsion has been investigated at pH 4.0. WPI and chitosan mixtures at various ratios were treated at pressure levels in the range of 0–600 MPa for 10–30 min. The emulsifying properties of the mixtures were analyzed by dynamic light scattering and a centrifugal sedimentation technique. HHP treatments of the mixtures resulted in improvement in their emulsifying properties, with the emulsions formed showing more than threefold reductions in droplet size, much more homogeneous droplet distribution, and better creaming stability. The higher the treatment pressure was, the smaller the droplet size and more stable the emulsions were, with those prepared with the mixtures treated at 600 MPa showing no noticeable creaming after 30 days of storage at ambient temperature. The ratio of WPI to chitosan and treatment time also affected the emulsification stability of the mixtures, with a WPI to chitosan ratio of 1:4 (w/w) and treatment time of 20 min found to be the optimum conditions. These results showed that HHP could be a useful method for enhancing the emulsifying properties of protein–polysaccharide mixtures.     

酶－微射流复合改性花生蛋白及其在微胶囊粉末油脂中的应用研究

以乳化性能为指标,采用胰蛋白酶-超高压微射流对花生蛋白复合改性,并以复合改性花生蛋白为主要壁材和乳化剂制备微胶囊粉末油脂。结果表明:复合改性可改善花生蛋白的乳化性能,花生蛋白经胰蛋白酶酶解后,在微射流均质压力100 MPa、均质1次的条件下,其乳化性能最佳;微胶囊粉末油脂复原乳状液粒径分布集中,平均粒径346.8 nm,在放置24 h内较稳定;微胶囊粉末油脂在实验时间内,表面油含量、酸值(KOH)和过氧化值分别控制在8%、3 mg/g和8 meq/kg内。     

Foaming and Emulsifying Properties of Whey Protein Concentrates As Affected by Lipid Composition

Freeze-dried WPC, containing 35 and 75% protein were manufactured by pretreating whey with calcium chloride and heat. These and commercial WPC were subjected to proximate analysis and lipid classes, phospholipid classes, free fatty acids (FFA), and monoacylglycerols (MAG) composition were determined. Solubility, thermal, foaming, and emulsifying properties of the WPC were studied. Pretreatment increased calcium and phosphorus contents and decreased the contents of all other minerals. The pretreatment had no effect on solubility, denaturation enthalpy, and onset temperature of denaturation of WPC. These values were comparable to those of commercial WPC. Foaming capacity and emulsion stability were unaffected, but foam stability increased and emulsifying capacity decreased due to pretreatment. Overall, total lipids and lipid class contents of experimental WPC were too low to affect surface properties of WPC.     

Influence of Emulsification Technique and Wall Composition on Physicochemical Properties and Oxidative Stability of Fish Oil Microcapsules Produced by Spray Drying

Encapsulation of fish oil is an effective way to protect it against oxidation and masking its fishy odor. One of the possible ways to produce fish oil microcapsules is to produce an oil-in-water (O/W) emulsion followed by spray drying. This study compares the production of the O/W emulsion by mechanical homogenization (rotor–stator) with membrane emulsification and examines the effect of the type and amount of wall material added before drying. The membrane emulsification process selected for the emulsion production is premix membrane emulsification (ME), which consists of the production of a coarse emulsion by mechanical means followed by droplet breakup when the coarse emulsion is forced through a membrane. The emulsions produced had an oil load of 10 and 20 % and were stabilized using whey protein (isolate and hydrolyzate at 1 or 10 %) and sodium caseinate with concentrations of 2 and 10 %. Regarding the material used to build the microcapsule wall, whey protein, maltodextrin, or combinations of them were used at three different oil/wall ratios (1:1, 1:2, 1:3). The results clearly show that premix ME is a suitable technology for producing O/W emulsions stabilized with proteins, which have a smaller droplet size and are more monodisperse than those produced by rotor–stator emulsification. However, protein concentrations of 10 % are required to reduce the droplet size down to 2–3 μm. Small and monodisperse emulsions have been found to produce microcapsules with lower surface oil content, which increases oil encapsulation efficiency and presents lower levels of oxidation during storage at 30 °C. Of all the possible combinations studied, the one with the highest oil encapsulation efficiency is the production of a 20 % O/W emulsion stabilized with 10 % sodium caseinate followed by the addition of 50 % maltodextrin and drying.     

Changes in the physicochemical,structural and emulsifying properties of chicken myofibrillar protein via microfluidization

Microfluidization is a novel and effective technology to improve the properties of myofibrillar protein. The effects of microfluidization with varying pressures (0–120 MPa) on the physicochemical, structural and emulsifying properties of chicken myofibrillar protein (CMP) were studied. Microfluidization treatment remarkably increased the absolute ζ-potential, contact angle, solubility, emulsifying ability and emulsifying stability of CMP. Simultaneously, the turbidity of CMP decreased. After microfluidization treatment, more α-helix structures were transformed into disordered structures, more hydrophobic and negatively charged groups were exposed, leading to improvements in CMP properties. After 90 MPa treatment, the absolute ζ-potential, storage modulus, loss modulus and dynamic apparent viscosity of CMP-camellia oil emulsion reached the maximum values. The hydrophobic interaction between CMP and camellia oil induced CMP to expose more hydrophobic and negatively charged groups, leading to the improved emulsifying properties of CMP. Our results demonstrate that microfluidization treatment has great potential to improve the product qualities of emulsion-type meat products.     

蛋白含量对牦牛乳清蛋白浓缩物功能特性的影响

通过不同截留分子质量的再生纤维素膜过滤纯化牦牛原乳清液和牦牛甜乳清液,分别制取牦牛原乳清蛋白浓缩物（native whey protein concentrate,NWPC）和牦牛甜乳清蛋白浓缩物（sweet whey protein concentrate,SWPC）,研究蛋白含量不同的乳清蛋白浓缩物（whey protein concentrate,WPC）主要成分（乳糖含量、pH值和总蛋白质含量）和功能特性（溶解性、持水性、持油性、起泡性、乳化性及热稳定性）的特征。结果表明：10 000 Da再生纤维素膜透析得到的牦牛WPC中总蛋白含量达到80%以上,不含乳糖,功能特性（溶解性、持水性、持油性、起泡性、乳化性及热稳定性）均显著高于经3 500 Da卷式膜、5 000 Da再生纤维素膜透析得牦牛WPC,WPC蛋白含量越高,其功能特性越好;不同蛋白含量的牦牛SWPC起泡能力、泡沫稳定性、乳化活性和乳化稳定性均显著（P＜0.05）高于牦牛NWPC。牦牛乳WPC最不稳定温度为85 ℃,高于荷斯坦牛乳WPC的80 ℃,热处理会适当改善牦牛WPC的起泡性能、乳化性能和热稳定性。通过膜牦牛处理获取的高蛋白含量的WPC,功能特性较好,应用广泛,对解决牦牛乳清资源的利用问题、保护环境、提高企业的经济效益起到关键性作用。     

Effect of monoglycerides and diglycerol-esters on viscoelasticity of heat-set whey protein emulsion gels

Summary Effects of small-molecule surfactants (emulsifiers) on the small-deformation viscoelastic properties of heat-set whey protein emulsion gels have been investigated using a controlled stress rheometer. The surfactants used in this investigation were the water-soluble diglycerol monolaurate (DGML) and diglycerol monooleate (DGMO), and the oil-soluble glycerol monooleate (GMO). The elastic modulus of the emulsion gel was found to decrease in the presence of a small amount of surfactant, but then to recover at higher surfactant concentrations. The initial reduction in modulus correlates with protein displacement from the oil droplet surface. The recovery of the storage and loss moduli at higher surfactant concentrations of DGML or DGMO may be due to the depletion flocculation of the emulsion prior to heat-treatment. However, for systems containing high content of GMO in the oil phase, the recovery of the moduli is probably owing mainly to the smaller average particle size. Effects of surface monolayer composition, droplet aggregation and average particle size were discussed. The behaviour obtained here was compared with results for previously investigated whey protein emulsion gel systems containing different emulsifiers.     

Feasibility of Discriminating Dried Dairy Ingredients and Preheat Treatments Using Mid-Infrared and Raman Spectroscopy

This study investigated the feasibility of mid-infrared (MIR) and Raman spectroscopy for (i) discrimination of three dried dairy ingredients, namely skim milk powder (SMP), whey protein concentrate (WPC) and demineralised whey protein (DWP) powder, and (ii) discrimination of preheat treatments of dried dairy ingredients using partial least squares discriminant analysis (PLS-DA). PLS1-DA models developed using MIR ranges of 800–1800 and 1200–1800 cm^?1 yielded the best discrimination (correct identification of 97.2% for SMP discrimination and 100% for WPC and DWP discrimination). The best PLS2-DA model using MIR spectroscopy was developed over the spectral range of 800–1800 cm^?1 and produced correct identification of 100% for dairy ingredient discrimination. Models developed using Raman 800–1800 and 1200–1800 cm^?1 spectral ranges correctly discriminated (100% correctly identified) each dairy ingredient. Although all PLS1-DA and PLS2-DA models developed using both spectral technologies for preheat treatment discrimination had good discrimination accuracy (86–100%), they employed a high number of factors (8–9 for the best model). The use of the Martens uncertainty test successfully reduced the number of factors employed (3–4 for the best models) and improved the performance of PLS1-DA models for preheat treatment discrimination (all 100% correctly identified). This feasibility study demonstrates the potential of both MIR and Raman spectroscopy for rapid characterisation of dried dairy ingredients.     

Solubilization Kinetics of Triacyl Glycerol and Hydrocarbon Emulsion Droplets in a Micellar Solution

Solubilization of oil molecules in surfactant micelles can have pronounced effects on the physicochemical properties of oil-in-water emulsions, e.g., reaction rates, distribution of nonpolar ingredients, emulsion stability and controlled flavor release. Static light-scattering was used to compare the solubilization kinetics of corn oil droplets with those of n-hexadecane droplets (ø= 0.02 wt%, d₃₂= 0.3 μm) in a micellar surfactant solution (2 wt% Tween 20). The n-hexadecane droplets were completely solubilized by the micelles within 5 days, but no change was observed in the corn oil emulsíon Possible reasons for the observed differences in solubilization kinetics were related to the molecular geometry and size of the oil molecules.     

超声辅助均质制备负载人参皂苷功能型Pickering乳液的工艺优化

目的 研制一种基于乳清分离蛋白和菊粉负载人参皂苷的Pickering乳液。方法 以乳清分离蛋白与菊粉复合溶液为水相,大豆油为油相,应用超声和均质处理方法制备负载人参皂苷的Pickering乳液。通过单因素试验考察乳清分离蛋白与菊粉的质量分数比、超声功率、超声时间、均质时间对人参皂苷乳液粒径的影响,利用Box-Behnken试验设计和响应面分析确定人参皂苷Pickering乳液的制备工艺。结果 对人参皂苷Pickering乳液粒径的影响程度从大到小依次为超声时间、均质时间、超声功率。优化的制备工艺参数:超声功率272.0 W、超声时间17.0 min、均质时间6.0 min,乳清分离蛋白与菊粉的质量分数比1:1.0。在优化条件下制备的人参皂苷Pickering乳液粒径最小为(318.73±1.24) nm。结论 应用超声辅助均质处理,制备基于乳清分离蛋白和菊粉负载人参皂苷的Pickering乳液工艺可行,为进一步构建人参皂苷纳米输送体系和功能食品研发奠定基础。     

Combined Superfine Grinding and Heat-Shearing Treatment for the Microparticulation of Whey Proteins

Microparticulated proteins (MPPs) considerably improve the texture, taste and nutritional value of low-fat dairy products. A combination of superfine grinding and heat-shearing treatment was utilized in order to improve the processing adaptability and stability of microparticulated whey protein (MWP). Comparing the mean particle sizes of WPC and MWP with the superfine milled whey protein concentrate (sWPC) and its microparticulated whey protein (sMWP), the sWPC and sMWP were significantly decreased from 49.24 and 13.09 μm to 8.17 and 5.73 μm, respectively (P?<?0.05). Both sWPC and sMWP exhibited higher water-holding capacity (1.9 and 3.69 g/g, respectively), emulsion activity index (146.38 and 128.6 m²/g, respectively), emulsion stability index (29.04 and 6.31, respectively) and viscoelasticity than WPC and MWP. The dispersion stability of sWPC, sMWP and its cream mimetic were also enhanced after superfine grinding treatment. The sMWP dispersion exhibited more stable liquid behaviour characteristics and maintained the creamy mouth feel better than MWP, indicating the higher dispersion stability of sMWP-based cream mimetic. Therefore, the combined superfine grinding and heat-shearing treatment is a promising technique for the production of microparticulated proteins.     

高压微射流制备橙皮精油纳米乳液影响因素研究

本文探讨了乳化剂类型、浓度和均质条件(压力和均质次数)对橙皮精油纳米乳液平均粒径(mean droplet diameter,MDD)、浊度以及贮藏稳定性的影响。采用四种乳化剂(皂树苷,QS;变性淀粉,MS;乳清分离蛋白,WPI;十二烷基硫酸钠,SDS),经高压微射流经不同均质压力和均质次数制备橙皮精油纳米乳液。结果表明,在一定范围,随着乳化剂浓度增加,MDD会逐渐减小,而SDS、QS、WPI和MS合适的浓度分别为2%、4%、4%和8%(w/w)。随着均质压力和均质次数增加,纳米乳液MDD和浊度都呈现较相似的减小趋势,在压力和次数分别增加到22000 psi和4次时,四种纳米乳液粒径可小于150 nm。研究发现,均质压力与MDD近似指数关系,乳液的相黏度比也会影响其MDD。贮藏实验表明,经25 ℃贮藏21 d,四种纳米乳液MDD基本稳定。