食品级大豆油W/O徽乳的制备研究

制备了水/Span80-Tween80/醇/大豆油食品级微乳。选用助乳化剂浓度法制备微乳液。用改良三角相图法筛选得到了能形成大豆油微乳的食品乳化剂。考察了助乳化剂及其浓度对增溶水量的影响。电导率法区分了微乳液的油包水(W/O)、双连续(B.C.)和水包油(O/W)类型。结果表明,大多单一食品乳化剂不能形成W/O大豆油微乳,Span80和Tween80复配后HLB值在9.7～12.9之间时能获得相对大面积的可转相微乳区域。乳化剂与油的相对比例不同,助乳化剂助溶效果不同。甘油是低乳化剂含量下效果相对较佳的助乳化剂,其浓度为25%时的增溶效果相对较好。     

胭脂虫红W/O/W乳液工艺

采用双乳化法制备胭脂虫红W/O/W复合乳液,以纯胭脂虫红酸水溶液作为内水相,大豆油为油相,司盘80、磷脂为亲油性乳化剂,将内水相、油相、亲油性乳化剂混合,在高剪切分散乳化机上以10 000 r/min的转速搅拌10 min,得到初乳。阿拉伯胶溶于水作为外水相,与初乳混合后用均质机均质后得到胭脂虫红W/O/W复合乳液。结果表明,采用双乳化法制备胭脂虫红W/O/W复合乳液,不仅能提高胭脂虫红在酸性条件下的稳定性,还能解决胭脂虫红在食品中形成色斑、不易涂抹问题,并能扩大胭脂虫红在食品领域的使用范围。     

基于三种多糖与酪蛋白复配制备W/O/W型乳液及其包封红景天苷效果的研究

为提高红景天苷稳定性及口服吸收效果,本研究以红景天苷为内水相,含聚甘油蓖麻醇酯的菜籽油为油相,分别采用葡聚糖、壳聚糖和大豆多糖混合酪蛋白作为外水相,制备W/O/W型多重乳液。研究了不同浓度的三种多糖对多重乳液的微观结构、粒径、电位、贮藏稳定性、乳化性、包埋率、载药量和体外消化过程的影响。结果显示,相比于酪蛋白对照组、壳聚糖-酪蛋白组和大豆多糖-酪蛋白组,葡聚糖-酪蛋白W/O/W型多重乳液稳定性最好。高浓度的葡聚糖能够明显提升葡聚糖-酪蛋白多重乳液的贮藏稳定性,当葡聚糖添加量为1.2%时,多重乳液平均粒径最小,可达623.03±5.21 nm（P<0.05）;电位绝对值最高（P<0.05）,平均电位为?37.3±0.46 mV;对酪蛋白乳化性质提升最大（P<0.05）;对红景天苷的包埋率最高（P<0.05）,可达92.8%,载药量为162.89±4.21 μg/g。模拟消化研究发现葡聚糖-酪蛋白多重乳液不仅能有效地保护红景天苷,还能够靶向地在模拟肠道内传递和释放,葡聚糖添加量为1.2%的葡聚糖-酪蛋白负载体系的稳定性和控释效果最佳。该研究结果可为红景天苷在食品和医药中的应用提供理论支撑。     

O/W型微乳液对β-胡萝卜素增溶作用

考察吐温80/乙醇/丁酸乙酯/水微乳液体系对水难溶性物β-胡萝卜素的增溶作用,同时用黏度计和动态光散射仪研究了空白微乳和含β-胡萝卜素微乳液的微结构。结果表明,β-胡萝卜素在以丁酸乙酯为油相的微乳液中溶解度明显增大;β-胡萝卜素加入明显影响微乳液的微结构。加入β-胡萝卜素使微乳液的W/O区域变小,BC和O/W区域变大;同样的,含β-胡萝卜素微乳液的粒径较空白微乳大,含β-胡萝卜素微乳液的粒径同空白微乳液一样,在储藏初期逐渐减小,3d后,基本不变,且在一个月内稳定。     

南极磷虾油W/O型微乳液制备及稳定性研究

目的:制备一种南极磷虾油微乳包埋方法并研究其稳定性。方法:以肉豆蔻酸异丙酯(IPM)为油相,Tween 80和Span 80复配表面活性剂相,乙醇为助表面活性剂,制备南极磷虾油油包水(W/O)型微乳液,并利用拟三元相图法考察各组分对微乳的影响。通过动态光散射法测定微乳液在离心试验、高温试验、盐度试验、贮藏试验中微乳液粒径大小变化,考察微乳液的稳定性。结果:在复配表面活性剂中,Tween 80和Span 80的质量比为6∶4,乙醇作为助表面活性剂且与表面活性剂质量比K_m=1.0时,得到稳定性良好的微乳液体系。结论 :该南极磷虾油微乳液制备简便,稳定性良好,是一种新型南极磷虾油的包埋方法。     

基于胃消化动态模型乳酸菌对大豆蛋白-磷脂复合乳液的影响

采用磷脂和大豆分离蛋白作为乳化剂,制成稳定的W/O型(油包水)和O/W型(水包油)大豆蛋白-磷脂复合乳液,研究在胃消化动态模型下乳酸菌对乳液的影响。通过对消化后乳液的粒径、电位、浊度的检测和显微观察,结果发现W/O型不加乳酸菌乳液粒径从(1157±57.75)nm增加到(2620±83.43)nm,电位从(—52.9±0.85)mV增加到(—4.64±0.14)mV,浊度从784.5±1.13降低到27.5±0.64;W/O型加乳酸菌乳液粒径从(1173±48.0)nm增加到(1405±67.07)nm,电位则从(—45.72±2.08)mV增加到(—3.44±0.16)mV,浊度从565±1.41降低到11.05±0.77。O/W型不加乳酸菌乳液粒径从(815±40.76)nm增加到(1026±51.3)nm,电位从(—52.1±2.18)mV增加到(—5.33±0.26)mV,浊度从173.95±1.49降低到32.9±0.63;O/W型加乳酸菌乳液粒径从(738±39.53)nm降到(403±18.95)nm,电位从(—40.06±2.01)mV增加到(—0.725±0.03)mV,浊度从131±0.70降低到26.15±0.32。加乳酸菌比不加乳酸菌乳液稳定性更差。加乳酸菌对大豆蛋白-磷脂复合乳液具有显著影响(P﹤0.01),说明乳酸菌加剧了乳液的破乳现象。     

以南极磷虾油为天然乳化剂制备O/W型乳液的工艺优化

南极磷虾油(AKO)在HLB值为6～16时具有较好的乳化能力,且在HLB值为8～11时表现最佳,倾向于形成水包油(O/W)型乳液。以南极磷虾油为乳化剂,鱼油为油相,制备O/W型乳液。研究了剪切速率、油相含量、AKO含量对乳液体系的影响,并利用单因素实验优化制备条件。结果表明:在南极磷虾油含量为3%,剪切速率为12 000 r/min,乳化时间为5 min,鱼油含量为60%条件下制备的乳液综合表现最好。     

基于熊果酸的W/O/W型Pickering乳液制备方法

目的:提高熊果酸的应用范围和生物利用率。方法:以熊果酸为乳化剂,果胶为外水相,采用两步法制备W/O/W型Pickering乳液。通过单因素试验优化W/O乳液制备条件,研究果胶质量浓度对W/O/W型Pickering乳液理化性质、微观结构、流变学特性及长期稳定性的影响。结果:W/O乳液的最佳制备工艺为熊果酸质量浓度4 g/100 mL、水油质量比2∶3、均质转速9 000 r/min、均质时间5 min;以果胶为外水相制备的双层乳液粒径均在30～40μm,果胶质量浓度的增加使乳液的zeta电位绝对值、流变性能以及4℃贮藏稳定性有着显著性的提高。结论:果胶质量浓度为0.3,0.4,0.5 g/100 mL时能够制备稳定的Pickering双层乳液。     

重质碳酸钙稳定的O/W型Pickering乳液及其粒度效应研究

以重质碳酸钙作为颗粒稳定剂制备O/W型Pickering乳液,利用球磨法获得不同尺寸的碳酸钙,研究碳酸钙颗粒粒度、颗粒浓度、油相比例对乳液类型、稳定性、微观形貌及流变学特性的影响。结果表明:球磨后不同粒度的碳酸钙均能稳定Pickering乳液,且该乳液具有一定的储存稳定性,固体颗粒粒径对乳液性质有一定的影响,乳液粒径随固体颗粒粒径的增大而增大;随固体颗粒浓度的增大,乳液的乳析指数、乳液粒径以及乳液黏度均减小,但当固体颗粒浓度达到9g/100 mL以上时,增加颗粒浓度对乳液粒径影响不大;增大油相比例会使乳析指数减小、乳液粒径和黏度增大。     

米糠蛋白O/W及W/O/W乳液制备及界面稳定性

为对比不同米糠蛋白质量浓度下O/W及W/O/W乳液的稳定性,以米糠蛋白作为基料,采用双乳化法制备O/W及W/O/W乳液,考察不同米糠蛋白质量浓度下乳液的微观形态和稳定性并探究其界面稳定机理。结果表明：W/O/W乳液的贮存稳定性显著优于O/W乳液;与相同蛋白含量的O/W乳液相比,W/O/W乳液的黏度显著提高;当米糠蛋白质量浓度为0.4 g/100 mL时,W/O/W乳液的稳定性较O/W乳液提高了1 倍以上;乳液内部包裹更多的W/O液滴,W/O/W乳液的粒径较大;而此时静电斥力也较大,起到稳定乳液的目的。同时,米糠蛋白质量浓度不小于0.4 g/100 mL时,O/W及W/O/W乳液中蛋白质的吸附率较高,达到78%以上。本研究为天然米糠蛋白质在食品级乳液中的开发提供参考,为粮食副产物的综合利用提供了新思路。     

W/O/W emulsions with high internal droplet volume fraction

We prepared water-in-oil-in-water (W/O/W) double emulsions with high internal aqueous droplet fraction using food-based ingredients. These compartmentalised materials were comprised of oil globules dispersed in an external aqueous phase, with the globules themselves containing densely packed inner aqueous droplets. We were able to obtain double emulsions with large globule fractions (up to 45 vol.%) using only 5 vol.% oil (relative to the overall composition). In the final state, the inner droplet fraction within the globules could exceed 90 vol.%. The method was based on two successive emulsification steps, followed by osmotic swelling (transport of water from the external phase to the inner droplets through the oil phase). During the final step, the swelling was controlled by the osmotic pressure mismatch between the external and internal aqueous phases using solutes dissolved at different concentrations. The osmotic swelling model of Mezzenga et al. (Langmuir, 2004, 20, 3574-3582) was re-adapted in the limit of small Laplace pressures to predict the final composition resulting from osmotic equilibration. The internal droplet fraction was lower than that predicted by the model as a consequence of coalescence phenomena occurring during the swelling process. The proposed approach constitutes a valuable guide within the prospect of formulating emulsions with enhanced encapsulation capacity and reduced fat content.     

Enhancing anti-inflammation activity of curcumin through O/W nanoemulsions

High-speed and high-pressure homogenized O/W emulsions using medium chain triacylglycerols (MCT) as oil and Tween 20 as emulsifier, with mean droplet sizes ranging from 618.6 nm to 79.5 nm, have been successfully prepared. The enhanced anti-inflammation activity of curcumin encapsulated in O/W emulsions is evidenced by the mouse ear inflammation model. There is a 43% or 85% inhibition effect of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced edema of mouse ear for 618.6 nm and 79.5 nm 1% curcumin O/W emulsions, respectively, but a negligible effect is found for 1% curcumin in 10% Tween 20 water solution.     

Surface-active solid lipid nanoparticles as Pickering stabilizers for oil-in-water emulsions

Oil-in-water (O/W) emulsions solely stabilized by surface-active solid lipid nanoparticles (SLNs) were developed. The SLNs were generated by quench-cooling hot O/W nanoemulsions consisting of 7.5% glyceryl stearyl citrate (GSC) dispersed in water. Their initial volume-weighted mean particle diameter (～152 nm) and zeta potential (ca.-49 mV) remained unchanged for 24 weeks. O/W emulsions (oil phase volume fraction: 0.2) containing 7.5% (w/w) GSC SLNs in the aqueous phase were kinetically-stable for 12 weeks and did not visually phase-separate over 24 weeks. The O/W emulsions generated with solid-state GSC SLNs had a volume-weighted mean oil droplet diameter of ～459 nm and a zeta potential of ca.-43 mV. Emulsion microstructure evaluated with TEM revealed dispersed oil droplets sparsely covered with adsorbed Pickering-type SLNs as well aggregated SLNs present in the continuous phase. Gradual emulsion destabilization resulted from GSC SLN dissolution during the experimental timeframe. Overall, surface-active SLNs developed via nanoemulsions effectively kinetically stabilized O/W emulsions.     

Preparation and Characterization of Water/Oil/Water Emulsions Stabilized by Polyglycerol Polyricinoleate and Whey Protein Isolate

ABSTRACT: In this study we tried to prepare stable water-in-oil-in-water (W/O/W) emulsions using polyglycerol polyricinoleate (PGPR) as a hydrophobic emulsifier and whey protein isolate (WPI) as a hydrophilic emulsifier. At first, water-in-oil (W/O) emulsions was prepared, and then 40 wt% of this W/O emulsion was homogenized with 60 wt% aqueous solution of different WPI contents (2, 4, and 6 wt% WPI) using a high-pressure homogenizer (14 and 22 MPa) to produce W/O/W emulsions. The mean size of final W/O/W droplets ranged from 3.3 to 9.9 μm in diameter depending on the concentrations of PGPR and WPI. It was shown that most of the W/O/W droplets were small (<5 μm) in size but a small population of large oil droplets (d > 20 μm) was also occasionally observed. W/O/W emulsions prepared at the homogenization pressure of 22 MPa had a larger mean droplet size than that prepared at 14 MPa, and showed a microstructure consisting of mainly approximately 6 to 7-μm droplets. When a water-soluble dye PTSA as a model ingredient was loaded in the inner water phase, all W/O/W emulsions showed a high encapsulation efficiency of the dye (>90%) in the inner water phase. Even after 2 wk of storage, >90% of the encapsulated dye still remained in the inner water phase; however, severe droplet aggregation was observed at relatively high PGPR and WPI concentrations.     

Viscosity change in oil/water food emulsions prepared using a membrane emulsification system

This paper reports viscosity measurements of oil/water (O/W) monodispersed emulsions of different droplet diameters obtained in a membrane emulsification system. Hydrophilic microporous glass membranes of different pore diameters were used to prepare O/W emulsions. The results showed that the droplet diameter of the emulsions varied with the average pore diameter of the membrane. The average droplet diameter was found to be about five times greater than the average membrane pore diameter. A correlation was found for the relationship between the average droplet diameter and the emulsion viscosity. As the dispersed droplet size became smaller, the total surface area of the droplets increased. Therefore, the emulsion viscosity and the relative viscosity increased. Few studies have reported the viscosity of O/W emulsions with droplet diameter of 5 μm or more and an oil phase concentration of 10 vol% or less. In the present study a correlation between the droplet diameter and the emulsion viscosity was statistically established. ©     

碱热改性米渣谷蛋白对W/O/W型双重乳液稳定性的影响

目的：实现米渣谷蛋白在乳浊体系中的应用。方法：选取碱热改性米渣谷蛋白和span80,采用一步乳化法制备W/O/W型双重乳液,并考察蛋白浓度对双重乳液稳定性的影响。结果：当蛋白质量分数从0.5%升高至2.5%时,乳液大粒径峰消失,显微结构中液滴的双重结构增强,表观黏度及黏弹性提高,离心稳定性和贮藏稳定性增强。当蛋白质量分数为2.5%时,离心后乳清析出指数从37.21%降至10.56%,分层时间从6 h延长至96 h。蛋白质与span80形成复合膜共同稳定油水界面,形成中间态液滴,当界面蛋白足以形成刚性界面膜时,液滴从中间态转为稳定的双重结构;当蛋白质量分数为3.0%时,双重乳液发生絮凝使大粒径峰重新出现,稳定性下降,离心后乳清析出指数为16.48%,制备后96 h左右分层,过剩的蛋白质一部分参与内相液滴的构建,另一部分单独形成O/W型液滴吸附于大体积液滴外侧。结论：一步乳化法下,蛋白质量分数为2.5%时,可制得稳定双重乳液。     

Production of O/W Emulsions Containing Astaxanthin by Repeated Premix Membrane Emulsification

ABSTRACT: Oil-in-Water (O/W) emulsions are mainly produced by application of high mechanical stress or by membrane emulsification processes at low pressures. Advantages such as narrower droplet size distribution and lower operating costs make membrane emulsification processes more suitable for producing astaxanthin-loaded O/W emulsions. The characteristics of 1 of these membrane emulsification methods, called repeated premix membrane emulsification, are studied in this work. In this emulsification process, a pre-emulsion is repeatedly pushed through a hydrophilic or hydrophobic membrane. In this research, ahydrophilic membrane was used because the objective was to obtain an O/W emulsion. Pre-emulsions were produced by dispersing palm oil containing dissolved astaxanthin in water. The oil droplets were stabilized with a combination of 2 emulsifiers. Each O /W emulsion passed the membrane 3 times underpressures and disperse phase fractions of 5 to 15 bar and from 10 wt% to 40 wt%, respectively. To investigate the production of O/W emulsions by repeated premix membrane emulsification, mean Sauter diameters and fluxes were measured. To find the optimal ranges of pressure and dispersed phase fraction, a "2-level factorial design with central composite and stars points" experimental design was applied.     

Release rate profiles of magnesium from multiple W/O/W emulsions

Water-in-oil-in-water (W/O/W) emulsions were formulated based on rapeseed oil, olive oil, olein and miglyol. Polyglycerol polyricinoleate and sodium caseinate were used as lipophilic and hydrophilic emulsifiers, respectively. Magnesium was encapsulated in the inner aqueous droplets. Emulsion stability was assayed through particle sizing and magnesium release at two storage temperatures (4 and 25 °C) over 1 month. Irrespective of the oil nature, both the primary W/O and W/O/W emulsions were quite stable regarding the size parameters, with 10-μm fat globules and 1-μm internal water droplets. Magnesium leakage from W/O/W emulsions was influenced by the oil type used in the formulation: the higher leakage values were obtained for the oils characterized by the lower viscosity and the higher proportion of saturated fatty acids. Magnesium release was not due to droplet–globule coalescence but rather to diffusion and/or permeation mechanisms with a characteristic rate that varied over time. In addition, W/O/W emulsions were resistant to various thermal treatments that mimicked that used in pasteurization processes. Finally, when W/O/W emulsions were placed in the presence of pancreatic lipase, the emulsion triglycerides were hydrolysed by the enzyme. These results indicated a possible use of W/O/W emulsions loaded with magnesium ions in food applications.     

Impact of amylose from maize starch on the microstructure,rheology and lipolysis of W/O emulsions during simulated semi-dynamic gastrointestinal digestion

This study aims to examine the microstructure, rheology and lipolysis of water-in-oil (W/O) emulsions (40 wt.%) prepared with or without (Control) the addition of normal (NAM) and high amylose (HAM) maize starch during simulated digestion in a semi-dynamic gastrointestinal tract (GIT) model. Microstructural examinations showed modification in initial W/O emulsion droplets to multiple W₁/O/W₂ droplets during in vitro digestion. This is in line with the rheological results, where the shear viscosity and moduli in the oral phase were remarkably reduced after entering the intestinal phase. In comparison to control and NAM emulsions, HAM emulsions showed a more compact and continuous network structure and greater viscosity and elastic modulus throughout GIT digestion. These results support lipolysis, where fewer free fatty acids were released in the HAM emulsion (70%) than in the control (86%) and NAM (78%) emulsions. This work has provided an in-depth understanding of the digestion of W/O emulsions as influenced by amylose content, which is meaningful for the development of low-fat products with reduced lipid digestibility.