小麦醇溶蛋白-阿拉伯胶复合纳米颗粒的构建及其负载百里香酚研究

百里香酚作为天然防腐剂,其绿色、安全、高效,但其生物利用率较低。本实验以反溶剂法构建负载百里香酚的小麦醇溶蛋白-阿拉伯胶复合纳米颗粒,探究小麦醇溶蛋白储备液浓度、搅拌速度、pH值及盐离子浓度对小麦醇溶蛋白-阿拉伯胶复合纳米颗粒稳定性的影响。结果表明:当小麦醇溶蛋白储备液浓度在6%、搅拌速度在800 r/min时所得复合纳米颗粒具有良好的稳定性,复合纳米颗粒大小为223.6 nm,多分散指数为0.35,电位为-29.8 mV;而当pH=3～9、盐离子浓度小于30 mmol/L时,复合纳米颗粒稳定,体系澄清且无沉淀,且颗粒呈现纳米级。该结果表明小麦醇溶蛋白和阿拉伯胶通过静电相互作用力相结合,其产生的电荷屏蔽效应还能够抵御一定浓度的盐离子。此外,当纳米颗粒∶生育酚=5∶1时,包封率达到85.7%。负载百里香酚的小麦醇溶蛋白纳米颗粒在结合了阿拉伯胶之后其稳定性显著提高。     

反溶剂法制备姜黄素-高粱醇溶蛋白复合颗粒及其特性分析

以姜黄素为芯材,高粱醇溶蛋白为壁材,采用反溶剂法制备包埋姜黄素的高粱醇溶蛋白复合颗粒（简称复合颗粒）,并对其理化性质及稳定性进行研究。结果表明：姜黄素与高粱醇溶蛋白制备复合颗粒的最佳芯壁比（质量比）为1∶10,产品平均粒径为13.17?μm,电位为19.38?mV,得率为87.51%,包封率为62.61%,负载率为6.51%。相比于高粱醇溶蛋白颗粒,扫描电子显微镜显示：复合颗粒呈球形,但表面有多孔结构;红外光谱结果显示：复合颗粒位于1?534、1?655?cm－1等处的波峰均发生红移,α-螺旋含量减少,β-折叠含量增加。24?h紫外光照射后,高粱醇溶蛋白包埋的姜黄素光稳定性提高33%。复合颗粒的粒径和多分散性系数在30?d室内环境贮藏过程中均无明显变化,但在环境pH?5～6,颗粒易聚集。结果表明：高粱醇溶蛋白的包埋作用有益于提高姜黄素的稳定性,可为姜黄素和高粱醇溶蛋白的高值化利用提供理论依据。     

高粱醇溶蛋白消化性研究

该文介绍高粱醇溶蛋白的提取方法,特性和消化性测定方法,并简单分析高粱醇溶蛋白发展前景。     

玉米醇溶蛋白纳米颗粒的体外消化特性

为了研究基于天然生物大分子的纳米递送体系在消化过程中物理化学性质的变化,本研究以姜黄素(Curcumin)为芯材,玉米醇溶蛋白(Zein)为壁材,通过反溶剂沉淀法制备了包埋姜黄素的玉米醇溶蛋白纳米颗粒(CZNPs),通过光谱学方法和电子显微镜对CZNPs的物化性质进行了表征,并在体外模拟消化模型中对CZNPs的消化特性进行了研究。结果表明,当姜黄素与Zein的质量比为1:40时,姜黄素的包埋率最高,为99%±1%,制得的CZNPs为球形纳米颗粒,平均粒径为118.6±0.7 nm、Zeta电位为19.9±3.79 mV,且颗粒之间出现轻微粘连。在体外模拟胃消化过程中,随着消化时间的延长,CZNPs出现明显聚集,其平均粒径增至8000 nm;且部分Zein发生降解,生成小分子量的氨基酸,同时缓慢释放出姜黄素。在后续的模拟肠消化过程中,CZNPs的聚集程度随着消化时间的延长而明显减弱,但Zein没有继续降解,姜黄素的释放也没有明显增大。因此,玉米醇溶蛋白纳米颗粒是一种比较有效的口服递送体系,可能应用于功能性食品和口服药物的开发中。     

玉米醇溶蛋白/阿拉伯胶负载槲皮素纳米颗粒制备

以玉米醇溶蛋白为载体,阿拉伯胶为稳定剂,反溶剂法制备负载槲皮素的玉米醇溶蛋白-阿拉伯胶纳米颗粒。考察阿拉伯胶浓度、槲皮素与玉米醇溶蛋白/阿拉伯胶质量比、p H、盐离子强度等因素对纳米颗粒稳定性的影响。结果表明,阿拉伯胶质量浓度50 g/L,制得粒径201.5 nm,多分散指数0.35,电位-31.5 mV的稳定玉米醇溶蛋白/阿拉伯胶载体;槲皮素/玉米醇溶蛋白-阿拉伯胶质量比1︰10时,粒径、颗粒分散性、ζ-电位均在稳定范围内,且包封率和负载率能达到84.3%和13.96%以上;盐离子浓度高于30 mmol/L时,玉米醇溶蛋白与阿拉伯胶之间的静电作用减弱,纳米颗粒体系不稳定,发生聚集;纳米颗粒能经历广泛pH变化,不发生聚集,大幅提高了包埋对象的生物利用度。     

萝卜硫素-玉米醇溶蛋白纳米水分散体制备及性质

以低浓度的阿拉伯胶为稳定剂,采用反溶剂法制备萝卜硫素-玉米醇溶蛋白纳米水分散体,并对其理化性质及萝卜硫素的释放特性进行研究。结果表明:未包埋萝卜硫素的玉米醇溶蛋白-阿拉伯胶纳米颗粒平均粒径184. 1 nm,多分散指数0. 135,ζ-电位-33. 5 m V,包埋萝卜硫素的颗粒平均粒径159. 8～180. 2 nm,多分散指数0. 152～0. 198,ζ-电位-32. 1～-37. 5 m V,颗粒近球形;当萝卜硫素与玉米醇溶蛋白的质量比为1∶25时,包封率为92. 3%,载量43. 4 mg/g;随着二者质量比增加,包封率显著下降,载量增幅不大,约60. 6～78. 7 mg/g。随着pH升高,pH 2～4时颗粒平均粒径显著减小,pH 4～8时其变化不显著;随着环境温度升高,25～55℃时,颗粒平均粒径变化不显著,55～85℃,平均粒径从200 nm左右增加到350 nm左右。萝卜硫素释放结果表明,60 min内累计释放率接近50%,240 min内几乎完全释放。     

高粱醇溶蛋白提取工艺及其功能特性研究

通过单因素和响应面试验,研究超声辅助酶法制备高粱醇溶蛋白的最佳条件;以高粱醇溶蛋白为原料,研究静置时间、温度对醇溶蛋白持油性和持水性的影响。结果表明,超声辅助酶法制备高粱醇溶蛋白的最佳条件为:加酶量1%,酶作用时间3h,超声波作用时间19 min,乙醇浓度60%,该条件下蛋白提取率为(7.19±0.36)%;在温度35℃、静置时间40min条件下时,高粱醇溶蛋白持油性和持水性最大,分别为(2.84±0.15),(2.78±0.09)g/g。     

玉米醇溶蛋白-番石榴黄酮复合纳米颗粒的制备及其抗氧化活性

以番石榴为原料,通过超声波辅助提取番石榴黄酮,采用AB-8大孔树脂进行分离纯化,利用溶剂挥发自组装方法制备玉米醇溶蛋白-番石榴黄酮复合纳米颗粒(zein-guava flavonoid composite nanoparticles,ZGF).通过扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱和差示扫描量热法等技术...     

负载生育酚的玉米醇溶蛋白纳米颗粒的构建及性质表征

采用反溶剂法制备负载生育酚（TOC）的玉米醇溶蛋白（zein）-阿拉伯胶的复合纳米颗粒。探究不同zein ∶ AG比例,不同搅拌速度对zein-AG纳米颗粒稳定性的影响;不同pH值,不同盐离子浓度对负载TOC的zein-AG纳米颗粒稳定性的影响。试验结果表明：当zein ∶ AG质量比1 ∶ 1.5,搅拌速度800 r/min时所得纳米颗粒稳定性较好,粒径125.4 nm,多分散指数（PDI）0.19,电位-32.8 mV;当pH=3~9,盐离子浓度小于20 mmol/L时,zein-AG纳米颗粒相对稳定,表明zein和AG可有效结合,产生电荷屏蔽效应以抵御一定浓度的盐离子;负载TOC的zein纳米颗粒在结合AG后的稳定性显著提高,比负载TOC前对DPPH、ABTS和超氧阴离子都有更高的清除能力;zein/AG-TOC纳米颗粒能够在胃肠道模拟试验中实现缓释。     

小麦醇溶蛋白纳米颗粒稳定皮克林乳液的研究

目的 构建负载丁香酚的小麦醇溶蛋白/果胶纳米颗粒稳定皮克林乳液,提高丁香酚生物利用率。方法 通过反溶剂法制备复合纳米颗粒,以乳液粒径、乳析指数为指标,考察复合纳米颗粒对皮克林乳液稳定性影响;以抑菌率为指标,考察皮克林乳液中丁香酚的生物利用率。结果 当负载丁香酚的小麦醇溶蛋白/果胶纳米颗粒浓度达5.00%,油相比例不超过60%,盐离子浓度低于250 mmol/L,储藏时间60 d以内时:皮克林乳液液滴颗粒分散,体系较为稳定。与此同时,当皮克林乳液最小抑菌浓度为1.00 mg/mL时,可有效抑制大肠杆菌的生长。结论 负载丁香酚的小麦醇溶蛋白/果胶纳米颗粒可在油水两相间形成界面膜以稳定皮克林乳液,其抑菌性能通过延长食品货架期的形式应用于食品保鲜领域中。     

Characterization of ergocalciferol loaded solid lipid nanoparticles

Abstract: The use of solid lipid nanoparticles (SLNs) is a technique that has been widely used in the pharmaceutical industry for the last 2 decades and has become of increasing interest to food scientists due to its potential for encapsulation and controlled release. Ergocalciferol (vitamin D₂) is a bioactive compound whose deficiency may lead to rickets in children and osteomalacia in adults. In this study, ergocalciferol was encapsulated in tripalmitin SLNs stabilized by polysorbate 20 (Tween 20). SLN dispersions (5% w/w) were prepared by hot homogenization technique using a nozzle‐type high‐pressure homogenizer. Ergocalciferol at 0%, 5%, 10%, 15%, and 20% (w/w of lipid) was dissolved in the molten lipid at 80 °C, mixed with a 5% (w/w) aqueous solution of polysorbate 20 and homogenized at 138 MPa at 80 °C. Particle size, thermal properties, and microstructure were evaluated by dynamic light scattering (DLS), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) respectively. As the proportion of ergocalciferol in the SLN increased from 0% to 20%, the Z‐average values of the particles gradually decreased (P≤ 0.05) from approximately 120 nm to approximately 65 nm. DSC analysis of freeze dried SLN samples showed gradual decrease in enthalpies of fusion and crystallization for stable β‐subcell whereas for SLN dispersions, the enthalpy of fusion of unstable α‐subcell crystal increased with increased ergocalciferol loading. The TEM images of the ergocalciferol loaded SLN samples showed the presence of spherical as well as rod‐shaped nanoparticles. It was also observed that the turbidity of the SLN dispersions reduced noticeably with increased ergocalciferol loading. This finding could be useful in terms of fortification of clear juices with ergocalciferol. Practical Application: Solid lipid nanoparticles (SLNs) were used in this study to encapsulate vitamin D₂, a vitamin important for bone health. It was found that as the concentration of vitamin D₂ increased in the lipid phase of SLN dispersion, the clarity of the dispersion increased. Also, with increased vitamin D₂ concentration, the stability of lipid crystal structure was affected in a way that indicates higher capacity of lipid to incorporate the vitamin molecules and hence to protect them better from oxygen and light. This vitamin loaded SLNs may offer alternatives to milk and margarine as a source of vitamin D.     

负载虾青素淀粉纳米粒的表征与稳定性能研究

为了提高虾青素的稳定性,制备了淀粉接枝聚甲基丙烯酸甲酯纳米粒,然后采用透析法,将虾青素与纳米粒混合制成虾青素纳米粒。测定了淀粉及接枝共聚物的红外光谱、纳米粒的平均粒径、粒径分布、纳米粒形态,并以虾青素的丙酮溶液作为比较,对虾青素纳米粒的稳定性进行了测定。结果表明,虾青素纳米粒的平均粒径为(208.1±26.4)nm,分散系数为0.284±0.035;4 h光照后,虾青素纳米粒保留率为26.34%;30℃和50℃恒温避光下,贮存8 d时虾青素纳米粒的保留率分别为91.81%和83.44%;在p H=1、3、5、7、9或11条件下,虾青素纳米粒的保留率平均值为86.18%。      

姜黄素与茶多酚联用固体脂质纳米粒的制备及抗肿瘤活性研究

采用薄膜-超声法制备姜黄素与茶多酚联用的固体脂质纳米粒,采用HPLC-DAD法建立了纳米粒中姜黄素和茶多酚类共5个活性成分的同步含量测定方法,考察了联用固体脂质纳米粒在不同储存条件下的稳定性,并对其抗肿瘤活性进行了研究。结果表明:当配方为姜黄素与茶多酚联用混合物（含量比例1∶1）40 mg,硬脂酸120 mg,卵磷脂60 mg,吐温-80（1.0%）10 m L时,所得固体脂质纳米粒平均粒径为93.8 nm,多分散度（polydispersity index,PDI）0.172,Zeta电位为-44.5 m V,平均包埋率达到93.08%,载药量为12.81%;姜黄素和茶多酚类5个活性成分在4℃条件下储存稳定性良好;MTT法实验结果表明联用固体脂质纳米粒对Hep G2和A549肿瘤细胞较姜黄素、茶多酚单独给药有更强的肿瘤细胞抑制作用（p<0.05）。结果证明,姜黄素与茶多酚联用制备固体脂质纳米粒的工艺合理可行,包埋率高,粒度均匀,稳定性好,对肿瘤细胞具有明显的协同抑制作用。姜黄素与茶多酚两种天然酚类活性成分的联用在食品工业领域具有极大的潜力。      

Encapsulation and protection of resveratrol in kafirin and milk protein nanoparticles

Food proteins have been widely used as carrier materials for the encapsulation of bioactive ingredients. Combination with hydro-soluble proteins provides better properties to prolamin-based particles. Kafirin obtained from sorghum belongs to cereal prolamin proteins. In this study, kafirin nanoparticles in the absence and presence of beta-lactoglobulin (β-Lg) or casein were prepared for the encapsulation and protection of resveratrol. The particles stabilised by 2% β-Lg or 0.2% casein were the smallest in size. Encapsulation efficiency of resveratrol was between 67% and 76% in kafirin/milk protein particles and the highest in kafirin/casein particles. Encapsulation in kafirin/milk protein particles improved DPPH˙ scavenging capacity of resveratrol but decreased its ABTS˙⁺ scavenging capacity. Stability of resveratrol ranked in order kafirin/casein > kafirin/β-Lg ~ kafirin.     

Shelf life and delivery enhancement of vitamin C using chitosan nanoparticles

Chitosan with different molecular masses was reacted with sodium tripolyphosphate (STPP) to prepare different size nanoparticles, in which vitamin C was encapsulated. The effect of molecular weight (Mw) on nanoparticles efficiency, nanoparticles yield, size, and zeta potential was investigated in detail. Low Mw chitosan generated nanoparticles with better size, morphology, and delivery rate. In addition, the shelf life of encapsulated vitamin C increased as compared with its non-encapsulated counterpart. The release of vitamin C from the nanoparticles was pH-dependent. Quick release took place in 0.1 M phosphate buffer solution (PBS, pH 7.4), while the release was slow in 0.1 M HCl. In addition, in vivo release rate in digestive tract of rainbow trout nearly showed the same trend as the in vitro one.     

Hydrophobic-assembled curcumin–porcine plasma protein complex affected by pH

Porcine plasma protein (PPP) was used as encapsulation material based on its hydrophobic regulation through pH shifting, as follows: the exposed hydrophobic residues of PPP provide binding sites to curcumin at extreme alkaline pH value 12, and then, PPP–curcumin complex is formed by re-adjusting the pH to a near neutral value. The stability and dispersibility of curcumin were significantly improved by this pH shifting method with PPP as carrier. The highest encapsulation efficiency (65.4%) of curcumin–PPP complex was obtained at 0.2 mg mL⁻¹ curcumin concentration. The stability of curcumin–PPP complex improved with increasing ultimate pH value. The antioxidant activity of curcumin bound to the complex was comparable with that of native curcumin and did not get affected by heating at 121 °C for 1 min. Overall, a stable curcumin–PPP complex was formed by pH shifting method without organic solvents or specific equipment; this approach may considerably contribute to utilisation of PPP in the food industry.     

Formation of electrostatic complexes using sodium caseinate with high‐methoxyl pectin and carboxymethyl cellulose and their application in stabilisation of curcumin

Despite many reported bioactivities of curcumin, its application is limited due to its low bioavailability, solubility and stability. Proteins have been reported to stabilise curcumin in aqueous media, and stabilisation of curcumin could be enhanced when proteins form an electrostatic complex with polysaccharides. In this study, electrostatic complexes of sodium caseinate (NaCas) were prepared using high‐methoxyl pectin (HMP and NaCas‐HMP) and carboxymethyl cellulose (CMC and NaCas‐CMC). NaCas to polysaccharide ratio of 1:2 resulted in the lowest turbidity and sedimentation. The electrostatic complexes were more stable than native NaCas against pH change and ionic strength. Binding of curcumin to NaCas and the electrostatic complexes were confirmed by UV‐vis and fluorescence spectra and Fourier transform infrared spectroscopy (FT‐IR). The electrostatic complexes showed a higher binding constant and protected curcumin better than the native NaCas. This study suggests that the electrostatic complexes may be a superior carrier to NaCas at an acidic environment.