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。     

Occlusive power evaluation of O/W/O multiple emulsions on gelatin support cells

The water content of the stratum corneum plays an important role in providing skin suppleness and smoothness. The diffusion of water through the skin is limited primarily by the stratum corneum and the noncornified part of the epidermis has negligible water barrier properties. Multiple emulsions are vesicular systems utilized for the prolonged liberation of active ingredients. The O/W/O multiple emulsion type is employed in cosmetics because its high oil content is able to maintain an occlusive film (barrier) on the skin surface. The objective of this study was to determine the occlusive power of O/W/O multiple emulsions on gelatin support cells. The results showed that occlusive products form a uniform layer on the surface of gelatin after the test, whereas nonocclusive products form two layers: an aqueous phase on the gelatin, and an oil phase above the aqueous phase. Thus, the different occlusive powers are due to the homogeneity of this layer and to its ability to prevent water evaporation.     

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.     

W/O/W多重乳状液的实验研究

研究了W/O/W多重乳状液的制备方法及影响其稳定性的因素。通过正交试验选出较佳的工艺参数,获得了较稳定的W/O/W多重乳状液。     

Production of reduced-fat whipped toppings by solid fat-based W/O/W double emulsions: proof of concept

Water-in-oil-in-water (W/O/W) double emulsions present a reduced-fat alternative to conventional O/W food emulsions, as part of the dispersed oil phase is replaced with water. In this study, the concept of a reduced-fat whipped topping produced by W/O/W technology was proven. Whipping of a W/O/W emulsion, containing only 20% oil phase and a solid fat content of 78%, produced a superior whipped topping, in terms of firmness and overrun, compared to its whipped O/W emulsion counterparts. The presence of PGPR in the oil phase increased structure formation during whipping, while the additional dispersed-phase volume resulted in a better air inclusion. Two commercial monoacylglycerols (saturated and unsaturated) were investigated to improve the whipping properties of the produced W/O/W double emulsion. Both increased the susceptibility towards partial coalescence, thereby reducing whipping time and overrun, while increasing firmness of the produced whipped topping. Furthermore, the effect was stronger for the unsaturated than for the saturated monoacylglycerol.     

Protection of Lactobacillus acidophilus from the low pH of a model gastric juice by incorporation in a W/O/W emulsion

The protective effect of a W/O/W emulsion for Lactobacillus acidophilus from a model gastric juice was investigated in order to develop a method for utilizing the advantages of the probiotics. The bacteria were included in the inner-phase solution of the W/O/W emulsion, and a method for counting the viable-bacteria included in the W/O/W emulsion was developed. The relative viability of the bacteria included in the W/O/W emulsion was 49% at 2 h in the model gastric juice, whereas the viability of the bacteria directly dispersed in the juice declined to 1.3% even at 0.67 h. The relative viabilities of the encapsulated bacteria in the model gastric juice at 2 h were 0.12 and 1.10 for the emulsions having the median diameters of 11.9 and 25.4 μm, prepared with inner-phase volume ratios at 0.03 and 0.45, respectively. The relative viabilities of the bacteria in the W/O/W emulsions with the median diameters of 11 and 27 μm, prepared at the homogenization speed of 2.2×10⁴ and 9.8×10³ rpm, were 0.4 and 0.8, respectively. These results suggested that both the inner-phase volume ratio and the median diameter of oil droplet affected the relative viability of the included bacteria.     

The characterization of the semi-solid W/O/W emulsions with low concentrations of the primary polymeric emulsifier

Semi-solid multiple W/O/W emulsions with low concentrations (0.8, 1.6 and 2.4% w/w) of lipophilic polymeric primary emulsifier PEG-30-dipolyhydroxystearate (PDHS) have been formulated. Both emulsions, primary and multiple, were prepared with high content of inner phase (Phi1 = Phi2 = 0.8). All the formulations differ only in the lipophilic emulsifier concentration. Evaluating several parameters such as macroscopic and microscopic aspect, droplet size, accelerated stability under centrifugation and flow and oscillatory rheological behaviour, assessed the multiple systems. It is possible to formulate the semi-solid W/O/W multiple emulsions with low concentrations of PDHS as the primary emulsifier. It appeared that the highest long-term stable multiple emulsion with the lowest droplet size, the highest apparent viscosity and highest elastic characteristic, was the sample with the highest concentration (2.4% w/w) of the primary emulsifier.     

In vitro skin permeation of sunscreen agents from O/W emulsions

The effects of different emulsifiers on the in vitro permeation through human skin of two sunscreen agents [octylmethoxycinnamate (OMC) and butylmethoxydibenzoylmethane (BMBM)] were investigated from O/W emulsions. The test formulations were prepared using the same oil and aqueous phase ingredients and the following emulsifier and coemulsifier systems: Emulgade SE((R)) (ceteareth-12 and ceteareth-20 and cetearyl alcohol and cetyl palmitate) and glycerylmonostearate (emulsion 1); Brij 72((R)) (steareth-2), Brij 721((R)) (steareth-21) and cetearyl alcohol (emulsion 2); Phytocream((R)) (potassium palmitoyl-hydrolysed wheat protein and glyceryl stearate and cetearyl alcohol) and glycerylmonostearate (emulsion 3); Montanov 68((R)) (cetearyl glucoside and cetearyl alcohol) (emulsion 4); Xalifin-15((R)) (C(15-20) acid PEG-8 ester) and cetearyl alcohol (emulsion 5). The cumulative amount of OMC that permeated in vitro through human skin after 22 h from the formulations being tested decreased in the order 3 > 1 congruent with 4 > 5 > 2 and was about nine-fold higher from emulsion 3 compared with that from emulsion 2. As regards BMBM, no significant difference was observed as regards its skin permeation from emulsions 1, 3, 4 and 5, whereas formulation 2 allowed significantly lower amounts of BMBM to permeate the skin. In vitro release experiments of OMC and BMBM from emulsions 1-6 through cellulose acetate membranes showed that only emulsions 4 and 5 provided pseudo-first-order release rates only for OMC. The results of this study suggest that the type of emulsifying systems used to prepare an O/W emulsion may strongly affect sunscreen skin permeation from these formulations. Therefore, the vehicle effects should be carefully considered in the formulation of sunscreen products.     

超声处理大豆分离蛋白与壳聚糖复合物对O/W型乳液稳定性的影响

为探究超声处理大豆分离蛋白-壳聚糖（soybean protein isolate-chitosan,SPI-CS）复合物对形成O/W型乳 液性质的影响,主要研究了复合物表面疏水性、乳化活性、乳化稳定性与油-水界面张力、乳液粒径、乳液稳定性 之间的关系。结果表明：未经超声处理的SPI-CS复合物表面疏水性、乳化活性、乳化稳定性和界面吸附性较低,形 成的O/W型乳液粒径相对较大,约100 μm,乳液Zeta电位较低,乳滴有发生聚集的倾向。乳液贮存7 d后乳层析指数 最高。经超声处理后SPI-CS复合物形成的乳状液性质发生明显变化,随着超声功率的增加,形成的O/W型乳液的稳 定性有所增加：超声功率为400 W时SPI-CS复合物形成的乳液最为稳定,乳层析指数最低;当超声功率超过400 W 时,乳液的光学显微镜观察显示其粒径有所增大,同时乳液的Zeta电位、乳化活性和乳化稳定性明显下降,界面张 力降低缓慢。超声处理暴露了蛋白质分子的内部结构,使部分结构展开、柔性增加,促进了其与壳聚糖之间的静电 相互作用,说明超声处理的大豆分离蛋白与壳聚糖形成的复合物影响了O/W型乳液的稳定性及相关性质。     

Dispersion Stability of O/W Emulsions with Different Oil Contents Under Various Freezing and Thawing Conditions

Freezing and thawing of oil‐in‐water (O/W) emulsion‐type foods bring about oil–water separation and deterioration; hence, the effects of freezing and thawing conditions on the destabilization of O/W emulsions were examined. The freezing rate and thawing temperature hardly affected the stability of the O/W emulsion. O/W emulsions having different oil fractions were stored at temperatures ranging from –30 to –20 °C and then thawed. The stability after thawing depended on the storage temperature, irrespective of the oil fraction of the emulsion. A good correlation was found between the time at which the stability began to decrease and the time taken for the oil to crystalize. These results indicated that the dominant cause for the destabilization of the O/W emulsion during freezing and thawing is the crystallization of the oil phase and that the effects of the freezing and thawing rates on the stability are insignificant.     

酒精对酪蛋白酸钠溶液及O/W乳状液的影响

介绍了酒精对酪蛋白酸钠溶液及酪蛋白稳定的O/W乳状液性质的影响 .试验表明酒精在一定程度上可以降低酪蛋白酸钠的溶解度 .界面张力的测定则表明酒精的存在在很大程度上可以降低油—水界面和油—酪蛋白溶液界面的界面张力 .含酒精的乳状液体系的粘度会由于酒精的存在而提高 ,在酒精体积分数达 3 0 %时 ,乳状液体系的粘度会突然大幅度升高 .通过O/W乳状液的分层稳定性测定可发现 ,低浓度的酒精可以提高酪蛋白稳定的乳状液的分层稳定性 ,但酒精质体积分数超过 3 2 %时 ,乳状液的分层稳定性会受到破坏 .含酒精的O/W乳状液体系中油相含量的提高在一定范围内可以提高乳状液的稳定性 ,但高分散相浓度的含酒精的乳状液体系中由于连续相中酒精浓度的提高使乳状液体系稳定性下降 .     

紫苏球蛋白乳化性及其O/W乳液的稳定性研究

将紫苏籽粉碎过60目筛后采用石油醚脱脂得到紫苏籽脱脂粉,采用osborne法提取紫苏球蛋白,研究其乳化性质,并将其应用于水包油(oil in water,O/W)乳液,进一步研究紫苏球蛋白浓度对乳液稳定性影响.结果表明,紫苏脱脂粉中球蛋白含量较高,其溶解性、乳化活性和乳化稳定性在pH 2～9,呈现U型曲线;球蛋白质量浓...     

一种水包油包胶型乳液的制备及其在乳化肠中的应用

以结冷胶和无水氯化钙为内水相凝固剂,酪蛋白酸钠为外水相乳化剂,制备一种水包油包胶（S/O/W）型 乳液。以多重乳液粒径和分布为指标,研究酪蛋白酸钠添加量对S/O/W型多重乳液加工适应性的影响。结果表明： 正交试验得到S/O型单重乳液最佳制备条件为：内水相中结冷胶添加量0.2%、无水氯化钙添加量0.5%;内水相乳化 剂聚甘油蓖麻醇酯添加量2.5%;油相为精炼猪油,油水体积比3∶2;剪切速率17 500 r/min,剪切时间1.5 min。将制 得的S/O型单重乳液与不同添加量酪蛋白酸钠混合制得S/O/W型多重乳液。当酪蛋白酸钠添加量0.1%时,S/O/W型 多重乳液粒径符合加工要求,且贮藏、热处理、剪切稳定性较好。以多重乳液替代猪脂肪制备的低脂乳化肠与高脂 （精炼猪油含量20%）乳化肠外观不存在明显差异;微观结构观察结果表明,多重乳液在乳化肠中包裹良好、分布 均匀。     

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.     

Protection of Lactobacillus acidophilus from bile salts in a model intestinal juice by incorporation into the inner-water phase of a W/O/W emulsion

Lactic acid bacteria have been paid increasing attention as a probiotics, but their viability is affected by the various digestive processes of their host such as the acidic stomach solution and bile acids. The protection of Lactobacillus acidophilus JCM 1132 against the cytotoxic bile acids was examined by incorporating the bacteria in the inner-water phase of a W/O/W emulsion. Sodium glycodeoxycholate and sodium glycochenodeoxycholate (6 mmol/l each) significantly decreased the cell viability from 5.2×10⁶ cfu/ml to 4.0×10³ and 1.3×10² cfu/ml, respectively, when the bacteria were directly dispersed in the solutions at pH 7 for 2 h. However, their incorporation in the inner-water phase of the W/O/W emulsion improved the viabilities to 1.6×10⁶ and 2.3×10⁴ cfu/ml, respectively. This improvement was ascribed to the inclusion of the bacteria in the emulsion because the viability of the bacteria, which were dispersed with the emulsion containing no bacteria in the solution, was very low. Although sodium deoxycholate decreased the viability of the cells included in the W/O/W emulsion, the inclusion significantly improved the cell viability against primary and secondary bile acids.     

酪蛋白酸钠-明胶制备S/O/W乳状液的稳定性

碳酸钙是一种常用的强化钙,然而,其悬浮稳定性差,易产生沉淀,严重限制了碳酸钙在食品加工中的应用.以固/油/水(S/O/W)乳状液形式负载碳酸钙,构建具有特定结构分布的钙-脂质微球,有望改善其溶解性和稳定性.本文以食品级碳酸钙为S相,大豆油为O相,酪蛋白酸钠-明胶为W相,构建S/O/W钙-脂质微球,研究不同质量分数明胶和...     

W/O/W型复乳的制备优化及包埋矢车菊素-3-葡萄糖苷效果分析

研究制备方法和乳化剂对W/O/W型复乳稳定性的影响,优化工艺参数,并研究体系包埋矢车菊素-3-葡萄糖苷（cyanidin-3-glucoside,C-3-G）的效果。得到优化条件：初乳搅拌速率15 500 r/min、复乳搅拌速率7 000 r/min、油相乳化剂聚甘油蓖麻醇酯添加量16%、亲水性乳化剂的亲水亲油平衡值10、亲水性乳化剂添加量10%,优化后离心保留率达到80.25%。利用优化得到的复乳体系包裹C-3-G,发现复乳对C-3-G有良好的包裹能力,复乳对C-3-G的载药量为1 500 mg/L,包封率为98.08%,且C-3-G的包埋提高内水相渗透压和复乳稳定性。     

壳聚糖W/O型乳状液的超声辅助制备及其稳定性

以非牛顿假塑性大分子壳聚糖溶液为水相,棕榈油为油相,Span-80为乳化剂,采用单因素试验及响应面试验优化超声协助制备W/O型乳液工艺,并考察优化条件下制备的乳液稳定性.结果表明:内水相含量是影响乳液粒度大小的关键因素,且超声功率对乳液的粒度及其分布存在过处理现象.优化工艺为超声功率300 W、超声时间15 min、内...     

马铃薯蛋白水解物对不同乳化剂制备O/W乳状液氧化稳定性的影响

用Fenton催化氧化体系模拟氧化,催化剂FeCl3,H2O2,VC的浓度分别为5、5、0.1mmol/L,以脂肪氧化产物丙二醛为指标,考察了马铃薯蛋白和不同乳化剂(非离子乳化剂Tween20、阴离子乳化剂卵磷脂和大分子乳化剂酪蛋白酸钠)共乳化制备得到的乳状液的氧化稳定性,并测定了相应乳状液的乳化稳定性。酪蛋白酸钠和马铃薯水解蛋白作为乳化剂得到的乳状液氧化稳定性较好,而Tween20和马铃薯蛋白水解物作为乳化剂得到的乳状液物理稳定性较高。     

Rheology: how to characterize and to predict the evolution of W/O/W multiple emulsions

The purpose of this work was to compare the evolution of three multiple emulsions (ME) by different controls. The series of water-in-oil-in-water (W/O/W) multiple emulsions were elaborated and controlled by both the usual analyses which permitted the classification of the multiple emulsions with respect to their thermal stability, and the rheological oscillatory and flow analyses which are polyvalent methods. Further, these allow the 'identity card' of the multiple emulsion to be drawn, its evolution to be followed, and moreover, its behaviour being foreseen by simulating ageing by shear. Three different behaviours are observed; a destructuration, a phase inversion and stability.