表没食子儿茶素没食子酸酯(EGCG)抗氧化微乳液的制备与表征

以肉豆蔻酸异丙酯为油相,吐温80-司盘80复配表面活性剂(HLB为6)为表面活性剂,乙醇为助表面活性剂(Km值为4∶1)制备了油包水型的表没食子儿茶素没食子酸酯(EGCG)抗氧化微乳液,并对其稳定性和抗氧化活性进行考察。通过测定电导率鉴别微乳液类型,纳米粒度仪测定微乳液的粒径,考察25℃条件下贮藏时间对微乳粒径的影响,评价微乳液的稳定性。同时,采用氧化稳定仪测定EGCG微乳液在花生油和亚麻籽油中的抗氧化活性。结果表明,微乳液外观澄清透明,在25℃贮藏条件下的稳定性好,放置50 d后微乳液的粒径变化小,放置期间未出现分层、破乳现象,并且在植物油中表现出较好的抗氧化活性。     

板栗花精油微乳的制备工艺

本文采用转相乳化法制备板栗花精油微乳,并通过伪三元相图考察表面活性剂、助表面活性剂、表面活性剂与助表面活性剂的比值(Km值)和油相对微乳形成的影响,以确定板栗花精油微乳的最优制备工艺参数。结果表明:板栗花精油微乳的最佳工艺为:聚乙二醇硬脂酸酯-15(HS-15)为表面活性剂,甘油为助表面活性剂,Km为2,油酸乙酯(EO)与精油等比例混合为油相,所制备的板栗花精油微乳为O/W型。以最佳微乳配方中混合表面活性剂与油相比例7∶3为试样,微乳的特性参数电导率、黏度和p H分别为180.2μs/cm,44.7 m Pa·s和6.66。此研究为板栗花精油微乳的制备及应用提供技术支持。     

食品级肉豆蔻酸异丙酯微乳的制备研究

本文以肉豆蔻酸异丙酯为原料,筛选出肉豆蔻酸异丙酯空白微乳的最佳配方。首先采用伪三元相图法,以微乳区面积为指标,筛选出表面活性剂和助表面活性剂;探究表面活性剂与助表面活性剂质量之比Km值与亲水亲油平衡值(HLB值)对微乳形成的影响,然后以离心和染色实验来判断微乳的稳定性和构型。结果表明:当以肉豆蔻酸异丙酯作为油相,吐温80复配司盘80作为复合表面活性剂,无水乙醇为助表面活性剂(表面活性剂∶助表面活性剂∶IPM=4∶2∶4),且Km=2∶1,HLB=7.5时,形成的微乳液稳定性最好。此条件下,油包水型微乳的最大载水量为15.3%。因此可以说明伪三元相图法制备肉豆蔻酸异丙酯方法方便可行。     

胡椒叶精油微乳液的构建及其抗氧化活性分析

本研究的目的是构建一种改善胡椒叶精油在水相环境中应用的微乳体系.以胡椒叶为原料,采用水蒸汽蒸馏法提取胡椒叶精油,通过绘制伪三元相图选择合适的微乳液组分制备胡椒叶精油微乳液,考察不同表面活性剂、助表面活性剂和Km值等因素对微乳区域面积的影响.最终制备以Tween 80为表面活性剂,无水乙醇为助表面活性剂,去离子水为水相的...     

食品级非离子表面活性剂微乳的制备及抗菌性研究

制备一种稳定的食品和药剂包埋载体—食品级非离子表面活性剂空白微乳,并评价其抗菌性。通过滴定法绘制伪三元相图来筛选形成微乳的组分及条件,以高速离心法和37℃恒温1个月考察微乳稳定性,利用透射电镜和粒径分析仪研究微乳粒子的形态和粒径分布,并分析其抗菌能力。以丁酸乙酯为油相、聚氧乙烯醚蓖麻油酯EL-35为表面活性剂、正丁醇为助表面活性剂、Km(表面活性剂与助表面活性剂的质量比)为3时微乳区最大,可无限稀释,平均粒径约17 nm。丁酸乙酯、聚氧乙烯蓖麻油EL-35、正丁醇和水复合液(1︰21︰7︰274)对金黄色葡萄球菌、大肠杆菌、沙门氏菌作用150 min后,能将其全部杀灭。该微乳性状稳定、毒性低、抗菌性强,适合作为食品、药剂等的载体。     

吐温-80制备食品级微乳的稳定性评价

以吐温-80为表面活性剂(S),乙醇、丙二醇和甘油为助表面活性剂(CS),大豆油、中链甘油三酸酯(MCT)和丁酸乙酯为油相(O)制备食品级微乳,通过测定粒径以及观察离心、温度、盐度、酸碱等环境因素对微乳外观上的影响,从而评价微乳的稳定性,并比较不同微乳的稳定性差异。结果表明:微乳的稳定性很好,是一个热力学稳定体系;以乙醇为助表面活性剂,以丁酸乙酯为油相,所制得的吐温-80食品级微乳稳定性最好。     

香茅草精油微乳液的构建及其抗氧化活性分析

本研究的目的是构建一种改善香茅草精油在水相环境中应用的微乳体系。以香茅草为原料,采用水蒸汽蒸馏法提取香茅草精油以及GC-MS联用技术对精油成分进行定性分析。通过绘制伪三元相图选择合适的微乳液组分制备香茅草精油微乳液,考察不同表面活性剂、助表面活性剂、Km值、pH值和离子强度等因素对微乳区域面积的影响。最终制备以Tween80为表面活性剂,无水乙醇为助表面活性剂,去离子水为水相的O/W型香茅草精油微乳液。其理化性质为:pH为6.73±0.02、黏度为15.50±0.11 mPa/s、电导率为108.90±0.21μs/cm、平均粒径为16.50±0.53 nm。最后,通过用DPPH,ORAC和PSC方法测定及比较香茅草精油与香茅草精油微乳液的抗氧化活性。结果表明,香茅草精油微乳液在水相环境中的抗氧化活性显著优于香茅草精油的效果(p0.05)。     

O/W型中链脂肪酸微乳的制备及其性质研究

以中链脂肪酸(MCFA)为原料,采用自微乳化法(HLB 值法)制备O/W 型中链脂肪酸微乳。考察了滴定方法,确定用蒸馏水滴定MCFA、表面活性剂和助表面活性剂三组分的混合物为最佳;比较乳化效率和伪三元相图中形成微乳面积的大小,得到MCFA 的最适HLB 值为15,最佳表面活性剂为单独使用吐温-80,最佳Km 值为2:1,最佳助表面活性剂是异戊醇。通过测定和评价微乳样品的各种性质,优化出最佳配方为MCFA:吐温-80:异戊醇:蒸馏水=3:2:1:0.68,表面张力可达到26.7142mN/cm,黏度65.22cP,电导率1.87μs/cm,平均粒径17.3nm,Zeta 电位－ 7.14mV,初步稳定性良好。     

聚甘油单月桂酸酯-油酸微乳体系的构建及其性能

为构建安全高效的微乳体系,提高姜黄素的溶解度,拓展微乳液及姜黄素在食品中的应用,制备具有较高姜黄素溶解度、可无限稀释的食品级微乳液。以油酸和不同聚合度的聚甘油单月桂酸酯、不同碳链长的醇为原料,通过对拟三元相图的分析,筛选表面活性剂和助表面活性剂,研究表面活性剂与助表面活性剂质量比（Km）、水相pH值和NaCl浓度对微乳体系相行为的影响,用电导率法分析微乳液的结构,用激光粒度仪和透射电镜测定观察微乳液滴的粒径、微观形貌。结果表明,以质量比为2∶1的六聚和十聚甘油单月桂酸酯复配为表面活性剂,以乙醇为助表面活性剂,Km=1/2,制备的微乳液效果最好,微乳区域面积占比最大,微乳液滴呈均一球形,粒径在10～100?nm之间。非中性的水相、NaCl的加入均会导致微乳区域面积占比的减小和最小可稀释比的增大。当表面活性剂与油相质量比为9∶1时,能够形成可无限稀释微乳体系,该体系结构在含水量小于45%时为W/O型,继续增加含水量,体系结构逐渐转变为双连续型,含水量超过60%时为O/W型。姜黄素微乳化不影响姜黄素生物活性,且姜黄素的溶解度可达4.87?mg/mL,可有效地解决姜黄素溶解性差、稀释性差的问题,说明微乳液是姜黄素的优良载体。     

番茄籽油微乳制备工艺的优化及稳定性研究

以番茄籽油为原料,通过对表面活性剂、助表面活性剂及油相等因素的选择优化,确定了番茄籽油微乳的基本制备工艺及其参数。结果表明:以Tween-80为表面活性剂、丙三醇为助表面活性剂,K_m(表面活性剂与助表面活性剂比值)值为2.68、混合表面活性剂与番茄籽油的比值为7.05时,乳化率为65.72%,乳化效果良好;同时考察了不同因素(高温、低温、光照、盐离子浓度和种类)对微乳稳定性的影响,研究表明微乳的低温、盐离子浓度稳定性较好,而高温、光照和盐离子种类稳定性较差。     

Preparation Methods for Monodispersed Garlic Oil Microspheres in Water Using the Microemulsion Technique and Their Potential as Antimicrobials

Garlic oil is considered as a natural broad‐spectrum antibiotic because of its well‐known antimicrobial activity. However, the characteristics of easy volatility and poor aqueous solubility limit the application of garlic oil in industry. The purpose of the present work is to develop and evaluate an oil‐free microemulsion by loading garlic oil in microemulsion system. Microemulsions were prepared with ethoxylated hydrogenated castor (Cremophor RH40) as surfactant, n‐butanol (or ethanol) as cosurfactant, oleic acid‐containing garlic oil as oil phase, and ultrapure water as water phase. The effects of the ratio of surfactant to cosurfactant and different oil concentration on the area of oil‐in‐water (O/W) microemulsion region in pseudoternary phase diagrams were investigated. The particle size and garlic oil encapsulation efficiency of the formed microemulsions with different formulations were also investigated. In addition, the antimicrobial activity in vitro against Escherichia coli and Staphylococcus aureus was assessed. The experimental results show that a stable microemulsion region can be obtained when the mass ratio of surfactant to cosurfactant is, respectively, 1:1, 2:1, and 3:1. Especially, when the mixture surfactants of RH40/n‐butanol 2/1 (w/w) is used in the microemulsion formulation, the area of O/W microemulsion region is 0.089 with the particle size 13.29 to 13.85 nm and garlic oil encapsulation efficiency 99.5%. The prepared microemulsion solution exhibits remarkable antibacterial activity against S. aureus.     

凉粉草精油微乳液抗氧化和抗A375细胞增殖活性

本实验以凉粉草为原料,通过水蒸气蒸馏法提取得到凉粉草精油,并运用气相色谱-质谱联用仪进行组成分析,依据峰面积计算得到相对含量较高的组分为香树烯（25.53%）、β-石竹烯（19.31%）、异石竹烯（11.30%）、甲位葎草烯（8.30%）、佛术烯（7.62%）。通过伪三元相图筛选得到以吐温60为表面活性剂,乙醇为助表面活性剂,表面活性剂与助表面活性剂质量比（Km）为2∶1,混合表面活性剂与油相的质量比（Smix）为8∶2的凉粉草精油微乳液,且该微乳液经100、200 倍稀释后仍保持稳定。凉粉草精油经微乳液包埋后的抗氧化活性得到不同程度的提高,其1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力略有提升,氧自由基吸收能力（oxygen radical absorbance capacity,ORAC）和过氧自由基清除能力（peroxyl radical scavenging capacity,PSC）分别提升为原来的2.6 倍和8.4 倍。此外,微乳液包埋同样提高了凉粉草精油对人恶性黑色素瘤细胞A375的增殖抑制作用,凉粉草精油微乳化后的半数效应质量浓度约为原来的1/5。综上,微乳液包埋较好地提升了凉粉草精油在水环境的抗氧化和抗A375细胞增殖活性,为凉粉草资源的高值化开发与利用提供了理论依据。     

响应面法优化茴香精油提取工艺及其微乳特性和货架期研究

本研究通过响应面法对茴香精油提取工艺进行优化,然后以茴香精油为油相、Tween 80+40为表面活性剂、丙三醇为助表面活性剂制备茴香精油微乳液体系,利用流变法、粒度仪及还原反应,对茴香精油微乳构型、粒径、总还原力及贮藏性进行探究。结果表明,当料液比1:8.40 g/mL,浸提时间4.09 h,颗粒粒度80目,浸提温度80 ℃时,茴香精油得率高达15.99%±0.10%。制备的茴香精油微乳粒径为30.92±0.13 nm,当水分含量高于60%时,为稳定的O/W型微乳。茴香精油的乳化明显提升了茴香精油的总还原力。根据化学反应动力学原理,建立Arrhenius方程为:k=2518.85·e?35583.09/RT,该模型预测茴香精油微乳在20、35、50和65 ℃下能贮藏 1899.18、932.03、492.94和 271.51 h,最大相对误差8.73%,误差较小,可准确预测该微乳的货架期。     

溶剂和微乳化的稀释效应对食用植物精油抗菌活性的影响

通过溶剂、乳化两种稀释载体制备植物精油复合物溶液,对其质量进行评价,测定最低抑菌浓度、最小杀菌浓度,分析其抗菌活性。结果表明:无水乙醇为溶剂,可改善植物精油的水溶性,其整体增强抗菌的效果不如1,2-丙二醇;以Tween80为表面活性剂、无水乙醇为助表面活性剂、牛至-百里香复合物(1∶1)为油相构建拟三元相图,制备微乳液,其外观为淡黄色、澄清透明液体;当Tween80与无水乙醇比值为3∶1时获得微乳区域的最大面积(29.55%)、最小可稀释比(9∶1);对微乳液的粒径分布、多分散指数、黏度、Zeta电位进行评价,发现微乳配方(10∶1∶28)的粒径最小(13.0 nm±0.6 nm)、多分散指数最低(0.231±0.020)、Zeta电位适宜(-22.23 mV±0.24 mV);植物精油经乳化后具有良好的耐盐、耐酸碱、耐糖、耐贮藏性,而其抗菌活性大大减弱。本研究为食用植物精油应用于食品“高效、安全”的防腐保鲜提供了理论依据。     

In vitro and in vivo antifungal activity of a water-dilutable cassia oil microemulsion against Geotrichum citri-aurantii

BACKGROUND: Recently, food‐grade microemulsions have been of increasing interest to researchers and have shown great potential in industrial applications. In this study a food‐grade water‐dilutable microemulsion system with cassia oil as oil, ethanol as cosurfactant, Tween 20 as surfactant and water was developed and its antifungal activity in vitro and in vivo against Geotrichum citri‐aurantii was assessed. RESULTS: The phase diagram results confirmed the feasibility of forming a water‐dilutable microemulsion based on cassia oil. One microemulsion formulation, cassia oil/ethanol/Tween 20 = 1:3:6 (w/w/w), was selected with the capability to undergo full dilution with water. The average particle size was 6.3 nm. The in vitro antifungal experiments showed that the microemulsion inhibited fungal growth on solid medium and prevented arthroconidium germination in liquid medium and that cassia oil had stronger activity when encapsulated in the microemulsion. The in vivo antifungal experiments indicated that the water‐dilutable microemulsion was effective in preventing postharvest diseases of citrus fruits caused by G. citri‐aurantii. CONCLUSION: The results of this study suggest a promising utilisation of water‐dilutable microemulsions based on essential oils for the control of postharvest diseases. Copyright © 2012 Society of Chemical Industry     

Antimicrobial activity of a food-grade fully dilutable microemulsion against Escherichia coli and Staphylococcus aureus

Microemulsions are colloidal nanodispersions of oil and water stabilized by an interfacial film of surfactant molecules, typically in conjunction with a cosurfactant. There is a limited number of reports in the literature on microemulsion use for antimicrobial purposes. The physicochemical characterization of a food-grade fully dilutable microemulsion system with glycerol monolaurate (GML) as oil, organic acids as cosurfactant, Tween 80 as surfactant, and the antimicrobial activities against Escherichia coli and Staphylococcus aureus have been studied in this paper. The influence of organic acids on oil solubilization was clearly reflected in the phase behavior of these systems. Propionic acid demonstrated the greatest capability to improve the oil solubilization among the tested linear and nonlinear chain organic acids and contributed to the formation of U-type microemulsion systems. One microemulsion formulation with an average particle size of 8 nm was selected, the composition is GML/propionic acid/Tween 80/water = 3:9:8:12. The kinetics of killing experiments demonstrated that the undiluted microemulsion caused a complete loss of viability of E. coli or S. aureus cells in 1 min and still had effective bactericidal effects even when diluted, more than 99% viable E. coli cells were killed within 15 min and a complete loss of viability was achieved at 45 min while more than 99% viable S. aureus cells were killed within 30 min and a complete loss of viability was achieved at 60 min in the presence of the 10-fold diluted microemulsion. The fast killing kinetics of the ten-fold serial dilutions of microemulsions were in good agreement with the mode of action studies, indicating that the interaction between the antimicrobial microemulsions and bacterial membranes significantly decreased the bacterial cell surface hydrophobicity and induced the quick release of 260 nm absorbing materials. This work suggests the potential use of food-grade fully dilutable microemulsions for antimicrobial purposes in beverages or seafood products.     

Formulation of a cosurfactant-free O/W microemulsion using nonionic surfactant mixtures

ABSTRACT:  A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.     

青花椒挥发油固体脂质纳米粒的制备及质量评价

制备青花椒固体脂质纳米粒,并考察其小鼠离体皮肤中的透皮吸收特征。微乳法制备SLNs,通过单因素考察,以挥发油为油相,硬脂酸聚乙二醇甘油酯(gelucire 50/13)为脂质载体,吐温80为乳化剂,丙三醇为助乳化剂,使用Box-Behnken设计-响应面法优化处方,Franz扩散池法比较青花椒挥发油与其SLNs的体外透皮吸收特征。结果表明,青花椒挥发油纳米粒最佳处方为丙三醇质量浓度3.67 g/L、药脂比6︰1、吐温80质量浓度4.67 g/L;测得SLNs平均粒径28.76±1.56 nm,多分散指数0.108±0.023,包封率92.24%±3.48%,纳米粒积累渗透量25.02μg/cm²,是原料的3.16倍。SLNs粒径小,分布均匀,包封率高,可促进药物的体外透皮吸收。     

橄榄油微乳体系的相行为及影响因素研究

本文以大豆卵磷脂和司盘80(Span80)复配为表面活性剂,乙醇为助表面活性剂,构建橄榄油微乳体系。采用拟三元相图法,考察亲水亲油平衡值(HLB值)、表面活性剂与助表面活性剂的比值(Km值)、盐浓度等因素对微乳体系相行为的影响,并通过电导率、负染透射电镜等方法研究微乳体系的结构,以优化体系配方、考察微乳液的形成规律。结果表明:大豆卵磷脂与Span80以质量比为3:1复配为混合表面活性剂,并与助表面活性剂无水乙醇按质量比(Km值)为2:1混合,所形成的大豆卵磷脂/Span80/乙醇/橄榄油/水微乳区域面积最大;甘油或少量盐离子的加入,可以在一定程度上增大微乳单相区的面积,但当盐浓度(C_NaCl)大于4 mol/L时,微乳区域面积明显减小;在大豆卵磷脂/Span80/橄榄油/乙醇/甘油/水微乳体系中,当水相(w_水/w_甘油=1:1)含量大于22 wt%时,体系逐渐由W/O型转变为双连续型结构。当水相含量超过30 wt%,体系则发生相分离。此研究为橄榄油微乳液的制备及应用提供理论和技术支持。