复配亚麻籽油和辅酶Q10乳液的制备及表征

亚麻籽油和辅酶Q10都具有水中溶解度低、稳定性差、生物利用度低等缺点。将亚麻籽油和辅酶Q10(coenzyme Q10,CoQ10)同时负载于乳液中,可解决两者的应用瓶颈。使用阿拉伯胶为乳化剂,采用高压均质法制备复配亚麻籽油和CoQ10乳液。采用动态光散射、透射电子显微镜、体外模拟消化、体外释放、稀释稳定性、冻融稳定性、离子强度稳定性、光稳定性和加速氧化稳定性方法对所制备乳液的理化性质进行表征。结果显示,制备的乳液平均粒径为(284±5.6) nm,多分散指数(polydispersity index,PDI)为0.112±0.025,为均匀分散的球形液滴。制备的乳液在模拟小肠液中消化,和亚麻籽油、CoQ10混悬液相比,乳化后亚麻籽油的消化速率和CoQ10的生物可给率明显提高。乳液中CoQ10的释放表现出缓释效果。制备的乳液具有较好的稀释和冻融稳定性。Na^+和Ca^2+会造成乳液Zeta电位的下降,对乳液稳定性影响较大。乳液载体化后CoQ10的光稳定性得到了提高。CoQ10对亚麻籽油具有较好的保护作用。     

玉米醇溶蛋白-壳聚糖纳米营养递送粒子的制备及性质

利用蛋白质和多糖构建纳米营养递送载体,是提高食品活性物质稳定性及利用率的重要手段。为了构建具有缓释特性的纳米营养递送体系,该研究以玉米醇溶蛋白（zein）为基材,构建玉米醇溶蛋白-壳聚糖纳米营养递送体系,以姜黄素（Cur）为营养模型,探究了壳聚糖分子量、zein与壳聚糖质量比对纳米粒子及其负载Cur性能的影响,通过扫描电子显微镜（Scanning Electron Microscope,SEM）、傅里叶红外光谱（Fourier Transform Infrared Spectroscopy,FTIR）等方法表征其结构,阐明复合纳米粒子形成机制,探讨其稳定性和缓释性能。结果表明：不同分子量的壳聚糖对纳米粒子的粒径、多分散性指数和zeta电位有影响。高分子量壳聚糖的加入可使纳米粒子粒径减小,且更加稳定。在zein与高分子量壳聚糖质量比为8∶1时,制备纳米粒子粒径较小（80.13 nm）,其zeta电位为46.18 mV;在此条件下,当姜黄素添加量为1.0%时,其包封率和负载量分别为82.93%和8.29%;通过SEM观察,纳米粒子呈球形,分布均匀;氢键及静电相互作用是组装该纳米粒子的作用力;壳聚糖的引入提高了纳米粒子的pH值、离子及储藏稳定性,扩展了其应用范围;与游离的姜黄素相比,纳米营养递送粒子呈现明显的缓释特性。研究结果为构建具有缓释特性的营养递送体系提供了理论基础。     

高压微射流法制备白藜芦醇纳米脂质体

为提高白藜芦醇生物利用率与缓释作用,采用高压微射流法制备白藜芦醇纳米脂质体,以纳米脂质体包封率为评价指标,在单因素试验的基础上,通过二次旋转回归试验设计确定最佳制备工艺.结果表明,最佳制备工艺为卵磷脂/VE=10∶1,卵磷脂/白藜芦醇=11.6∶1,卵磷脂/胆固醇=10.5∶1,微射流压力18 366 PSI,循环次数3次.在此条件下制得白藜芦醇纳米脂质体的包封率为87.74％±1.01％,平均粒径为78.31nm±1.37nm,Zeta电位为-55.5 mV.该方法制得的白藜芦醇纳米脂质体包封率高、粒径小、分布范围窄,且体系稳定.该研究为白藜芦醇新剂型的开发及利用提供理论依据和实际指导.     

CaCl2和pH值对水酶法提取大豆油形成乳状液破乳效果影响

为探明粗酶水相提取大豆油所产乳状液的破乳机制,通过破乳率、Zeta电位、黏度、粒径分布和平均粒径指标分别考察无机盐和pH值对乳状液稳定性的影响。为了比较无机盐的破乳效果,该文在乳状液中分别添加浓度均为0.06mol/L的CaSO_4、CaCl_2、MgCl_2、NaCl,80℃条件下反应10min,结果显示4种无机盐均可显著降低乳状液稳定性,其中CaCl2破乳率最高,然后依次为CaSO_4、MgCl_2、NaCl。尽管CaCl2在60、70、80℃时均可实现彻底破乳,但破乳率随CaCl_2浓度(0.02～0.08mol/L)、反应时间(0～90min)、反应温度(60～80℃)的增加而提升。CaCl_2实现彻底破乳后,破乳率随反应时间延长而下降。添加CaCl_2后乳状液的电位绝对值和黏度降低,油滴发生聚合,平均粒径增加,使乳状液稳定性下降。CaCl_2浓度和反应温度的提升均可导致电位绝对值和黏度下降程度增强,破乳率进一步上升。在50℃、pH为值3～9时,降低pH值可使乳状液电位绝对值和黏度显著下降,导致油滴平均粒径增加,乳状液稳定性下降。pH值为3~4时乳状液的电位绝对值最低,接近0,此时乳状液稳定性最低,破乳率最高。但当pH值小于3时,乳状液电位绝对值和黏度再次升高,致使油滴平均粒径和破乳率降低。光镜照片显示破乳后乳状液中油珠直径明显增大。该研究可为水酶法提取大豆油破乳技术提供理论依据。     

大豆油体乳液稳定性和流变性分析

研究大豆油体乳液的基本物理化学性质,将为其工业应用提供参考。以水为介质提取大豆油体,方法无毒,利于食用。对其在不同pH值（pH值2～8）、NaCl浓度（0～250?mmol/L）和加热处理（30～90℃,30?min）条件下的Zeta电位、平均粒径和乳析稳定性进行测定,并对其流变性进行考察。大豆油体乳液的Zeta电位为+20?mV～-40?mV（pH值2～8）,等电点约为4.5。在pH值≤3和pH值≥6条件下,平均粒径均为0.4?μm左右;而在3＜pH＜6时,产生了乳析现象。在较高NaCl浓度下（＞25?mmol/L）,粒径较大和发生了乳析现象。大豆油体乳液在30～90℃加热处理时较稳定。大豆油体乳液呈现出弱凝胶的性质,其黏度随着油质量分数的降低而降低。研究表明,大豆油体乳液在一定的环境条件下是稳定的。     

纳米化阿维菌素悬浮剂的制备及部分性质研究

为了使阿维菌素的分散性、稳定性、适应性更强,利用壳聚糖带阳离子的特性,使其与带阴离子的三聚磷酸钠发生离子交联,包裹部分阿维菌素颗粒后形成纳米载药颗粒,制备了水基纳米阿维菌素悬浮剂。透射电子显微镜、粒度分析仪和紫外分光光度法检测结果显示,在纳米阿维菌素悬浮剂中,悬浮粒子呈不规则圆形,87.46%粒子的粒径位于18～102.2nm之间,平均粒径为28.46nm,阿维菌素的载药量为48.25%,在光照下的稳定性增强,经过16h紫外光照,纳米阿维菌素悬浮剂中阿维菌素降解率为38.41%,比同样条件下制备的纳米化阿维菌素微乳剂降解率低11.46%,比原药的降解率低29.41%。该悬浮剂的分散性、离心稳定性都为优级,对水温、不同水质水的适应能力强。     

鸡白细胞介素2（IL-2）DNA-壳聚糖纳米粒的制备及体外转染

构建了携带鸡白细胞介素2(IL-2)编码基因的重组真核表达质粒,通过复凝聚法制备了含有该重组真核表达质粒的壳聚糖纳米粒子.对制备的IL-2DNA-壳聚糖纳米粒子(IL-2 DNA-chitosan nanoparticles)进行了表征.纳米粒子呈球形,粒径分布范围为50～500nm,表面带正电,电势为+17.8mV,DNA质量占纳米粒子总质量的40.2%.DNA酶保护性、稳定性和体外释放试验证明,制备的纳米粒子在微酸性(pH 6.0)和微碱性(pH 7.4)环境中稳定性较高,可保护携带的DNA分子不被0.6～0.8U/mL DNA酶的降解.用制备的纳米粒子转染Df-1细胞系,间接免疫荧光检测结果证明,该纳米粒子可携带质粒DNA进入细胞,使携带的外源基因获得表达.流式细胞术检测证明,纳米粒子的转染效率为0.2%,与裸DNA转染对照组相比较,包封入壳聚糖纳米粒子中可提高DNA的转染效率.     

壳聚糖与牛血清白蛋白作用机制及其复合物乳化性的研究

为探究蛋白质与多糖之间的相互作用及其复合物的研究乳化性质,本试验以牛血清白蛋白(BSA)-水溶性壳聚糖(WCS)复合体系为研究对象,采用紫外吸收光谱、荧光发射光谱、电位粒径分析、乳液储藏稳定性观察等方法研究在微观环境下蛋白质与多糖的相互作用机理,并进一步探究两者对水包油型乳液乳化性能的影响。结果表明,多糖和蛋白质的相互作用随着pH值和BSA/WCS复合比的变化而不同,混合溶液的紫外吸收峰和荧光发射峰发生偏移,且当复合比小于1∶2时发生荧光淬灭。混合溶液的Zeta电位和平均粒径测定结果表明,BSA与WCS之间主要通过静电相互作用形成复合物,且该复合物的电荷性质、尺寸大小具有pH值和复合比依赖性。研究混合溶液乳化性发现,当pH值为3.0、4.0、复合比为4∶1~1∶1时,形成的乳液液滴粒径较小,性质稳定;当pH 值大于5.0时,乳液液滴粒径大,出现相分离、乳液高度不稳定现象。本研究为设计具有可预测稳定性或刺激响应性的乳液配方及新型功能特性材料提供了理论依据。     

短链葡聚糖-姜黄素纳米乳液的制备及结构表征

利用短链葡聚糖(short glucan chains,SGC)的螺旋空间结构来包埋姜黄素(curcumin,CUR)。通过使用高剪切分散乳化机高速剪切溶液5 min,用纳米均质机在50 MPa压力下高压均质经剪切后的乳液2次制备成纳米乳液以提高其包埋率和载药量。XRD (x-ray diffraction)和TGA (thermogravimetric analysis)很好的验证了包合物的形成,通过TGA、SEM (scanning electron microscopy)、激光粒径分析仪等各种表征分析得出短链葡聚糖-姜黄素纳米乳液制备成功,所制得的乳液对姜黄素的包埋率和载药量都高于短链葡聚糖-姜黄素包合物,分别达到了71.11%和12.07%,说明制备成纳米乳液对姜黄素的包埋率和载药量都有了明显的提高。所制备的纳米乳液的粒径小于300 nm,粒径分布均一,Zeta电位观测表明所制得的乳液的稳定性有所提高。为提高食品及医药领域姜黄素的生物利用率提供了一定的参考意义。     

基于微波辐射法制备水溶性CdTe量子点及其表征研究

本文以巯基乙酸为稳定剂,采用微波辐射加热的方法快速合成水溶性Cd Te量子点,研究了不同的反应时间、反应温度及反应前驱体不同的p H值对合成Cd Te量子点光学性质的影响,采用TEM、XRD、紫外-可见吸收光谱和荧光光谱等技术对所制得产品进行表征。结果表明,在合成温度为160℃,微波功率800 W,加热时间为15 min,p H值为12.0条件下,所合成的Cd Te量子点荧光强度最强,量子产率较高(46.891%),半峰宽较窄(FWHM=45 nm、EM=563.6 nm)。与回流方法制备的水溶性Cd Te量子点相比,该合成方法简单,反应时间短,粒径较均匀,能够满足量子点作为荧光探针检测农产品中兽药残留的需要。     

Novel chitosan-derived nanomaterials and their micelle-forming properties

Six novel N-alkyl-N-dimethyl and N-alkyl-N-trimethyl chitosan derivatives were chemically synthesized and characterized using FT-IR, 1H NMR, 13C NMR, differential scanning calorimetry (DSC), and X-ray diffraction spectrometry (XRD). The alkyl groups included octyl (C8H17-), decanyl (C10H21-), and lauryl (C12H25-). These chitosan derivatives were also evaluated for their micelle-forming properties using dynamic light scattering (DLS) and transmission electron microscopy (TEM) techniques. All six chitosan derivatives were capable of forming polymeric micelles in water with an average particle diameter ranging from 36 to 218 nm. Both N-octyl-N-dimethyl and N-octyl-N-trimethyl chitosan derivatives formed nanomicelles under the experimental conditions, with an average particle diameter of 36.0 and 52.5, respectively. Both the length of alkyl group and the N-trimethylation degree of the chitosan derivatives altered the size of their polymeric micelles. To further understand the effect of N-alkyl substitution degree of chitosan derivatives on size of their micelles, additional five N-octyl-N-trimethyl chitosan derivatives with N-alkyl substitution degree ranging from 8 to 58% were prepared and their micelle sizes were determined. The results showed that the diameter of the nanomicelles was proportional to the degree of N-octyl substitution. These data suggest that novel N-alkyl-N-dimethyl and N-alkyl-N-trimethyl chitosan derivatives may form nanomicelles. Additional research is required to further investigate the potential value-added utilization of these chitosan derivatives in controlled release and targeted delivery of hydrophobic bioactive food factors.     

Preparation and characterization of nanoparticles containing trypsin based on hydrophobically modified chitosan

Trypsin was immobilized on linolenic acid modified chitosan using glutaraldehyde (GA) as cross-linker, which was confirmed by Fourier transform infrared (FTIR) spectra. The chitosan nanoparticles containing trypsin (TR) can be prepared after the sonication of immobilized trypsin. The GA concentration affected both the enzyme activity of the nanoparticle and particle size. Results indicated that the activity of trypsin immobilized onto linolenic acid modified chitosan nanoparticles increased with increasing concentration of GA up to 0.07% (v/v) and then decreased with increasing amount of GA. On the other hand, particle size increased (from 523 to 1372 nm) with the increasing concentration of GA (from 0.03 to 0.1% v/v). The enzyme catalytic characteristics of nanoparticle solution were also studied. The results showed that the kinetic constant value (K(m)) of TR immobilized on nanoparticle (71.9 mg/mL) was higher than that of pure TR (50.2 mg/mL). However, the thermal stability and optimum temperature of TR immobilized on nanoparticles improved, which make it more attractive in the application aspect.     

微波辅助合成壳聚糖基高吸水性树脂

在水溶性引发剂过硫酸钾(KDS)的引发下,用微波辐照使丙烯酸在壳聚糖分子链上接枝聚合,并加入N,N’-亚甲基双丙烯酰胺进行适度交联,制备高吸水性树脂。利用FT-IR对产物结构进行定性表征,结果表明,丙烯酸在壳聚糖的分子链上发生了接枝聚合反应。研究了反应条件对产物吸液性能的影响,并通过正交试验对工艺条件进行优化。在最佳条件下合成产物的吸水倍率为815.0g/g,吸生理盐水倍率为72.2g/g,吸人工尿液倍率为67.5g/g。在微波作用下产物合成速率是传统方法的数十倍,吸液性能明显高于后者,且操作条件容易控制,后处理步骤明显简化,无污染,是一种高效的清洁生产工艺。     

Effect of different preparation methods on physicochemical properties of salidroside liposomes

Salidroside liposomes were prepared by using five different methods: thin film evaporation, sonication, reverse phase evaporation, melting, and freezing-thawing. The effect of different preparation methods and salidroside loading capacity on the formation of liposomes and their physicochemical properties were evaluated by means of encapsulating efficiency, particle size, morphology, and zeta potential. Results showed that the encapsulating efficiency of liposomes was highest when prepared by freezing-thawing, followed by thin film evaporation, then reverse phase evaporation and the lowest with melting and sonication. Loading capacity of salidroside had a significant effect on encapsulating efficiency, average diameter, and zeta potential of liposomes. Liposomal systems prepared by sonication, melting, and reverse phase evaporation displayed better dispersivity. Determination of leakage of salidroside from different liposomal systems revealed that the melting method had the lowest leakage of 10% and 15%, at 4 and 30 degrees C after 1 month of storage, respectively. In all cases, a straight-line leakage behavior of salidroside was found. This revealed that the leakage of salidroside was a diffusion process from the membrane of liposomes. Furthermore, the storage stability of different liposomal systems showed that salidroside liposomes prepared by melting had a better physicochemical stability. Instability in the systems was exacerbated when temperature increased. Salidroside liposomes showed the slower increase in particle size than liposomes without salidroside. This could indicate that salidroside played an important role in preventing the aggregation and fusion of liposomes.     

Formation of hydrogel particles by thermal treatment of beta-lactoglobulin-chitosan complexes

Molecular complexes based on proteins and ionic polysaccharides have considerable potential for encapsulation of functional food components, but their widespread utilization is limited because their structure is highly sensitive to pH and ionic strength. We have investigated the possibility of creating stable hydrogel particles by thermal treatment of protein (beta-lactoglobulin) and cationic polysaccharide (chitosan) mixtures. Mixed solutions of beta-lactoglobulin (0.5 wt %) and chitosan (0.1 wt %) were prepared at various pH's (3-8) and were heated (80 degrees C for 20 min). Prior to heating, the biopolymer mixtures formed molecular complexes at pH values where there was an electrostatic attraction between the protein and the polysaccharide: soluble complexes at pH 4.5; complex coacervates at pH 5.0 and 5.5; precipitates at pH>5.5. After heating, relatively small (d approximately 140 nm) and cationic (zeta>+20 mV) hydrogel particles were formed at pH 4.5, but much larger aggregates were formed at pH 5.0 and higher (d>1000 nm). The thermally treated hydrogel particles formed at pH 4.5 maintained their initial particle size when the pH was subsequently adjusted within the range pH 3-5, but they aggregated when the pH was adjusted to >pH 5 because of a reduction in the magnitude of their electrical charge. This study suggests that hydrogel particles can be formed by heating mixed protein-polysaccharide systems under controlled conditions. These hydrogel particles may be useful for encapsulation of functional food components.     

Linolenic acid-modified chitosan for formation of self-assembled nanoparticles

Chitosan was modified by coupling with linolenic acid through the 1-ethyl-3-(3-dimethylaminopropyyl)carbodiimide-mediated reaction. The degree of substitution was measured by 1H NMR, and it was 1.8%, i.e., 1.8 linolenic acids group per 100 anhydroglucose units. The critical aggregation concentration (CAC) of the self-aggregate of hydrophobically modified chitosan was determined by measuring the fluorescence intensity of the pyrene as a fluorescent probe. The CAC value in phosphate-buffered saline (PBS) solution (pH 7.4) was 5 x 10(-2) mg/mL. The average particle size of self-aggregates of hydrophobically modified chitosan in PBS solution (pH 7.4) was 210.8 nm with a unimodal size distribution ranging from 100 to 500 nm. A transmission electron microscopy study showed that the formation of near spherical shape nanoparticles had enough structural integrity. The loading ability of hydrophobically modified chitosan (LA-chitosan) was investigated by using bovine serum albumin (BSA) as a model protein. Self-aggregated nanoparticles exhibited an increased loading capacity (19.85 +/- 0.04 to 37.57 +/- 0.25%) with an increasing concentration of BSA (0.1-0.5 mg/mL).     

用大孔树脂纯化栀子黄色素的研究

为降低栀子黄色素中栀子苷的含量，提高栀子黄色素稳定性，该文就10种大孔树脂纯化栀子黄色素进行了研究。结果表明，A-5大孔树脂选择性吸附藏花素的能力较强，吸附率和解吸率均达85%以上，经其纯化后的栀子黄色素OD值比率(即栀子苷在最大吸收波长238 nm处的吸光值与藏花素在最大吸收波长440 nm处的吸光值的比值)可降至0.4以下，实现了对藏花素与栀子苷的有效分离，适于栀子黄色素的纯化。     

Development of zein nanoparticles coated with carboxymethyl chitosan for encapsulation and controlled release of vitamin D3

In this study, zein nanoparticles coated with carboxymethyl chitosan (CMCS) were prepared to encapsulate vitamin D3 (VD3). VD3 was first encapsulated into zein nanoparticles using a low-energy phase separation method and coated with CMCS simultaneously. Then, calcium was added to cross-link CMCS to achieve thicker and denser coatings. The nanoparticles with CMCS coatings had a spherical structure with particle size from 86 to 200 nm. The encapsulation efficiency was greatly improved to 87.9% after CMCS coating, compared with 52.2% for that using zein as a single encapsulant. The physicochemical properties were characterized by differential scanning calorimetry and Fourier transform infrared spectroscopy. Nanoparticles with coatings provided better controlled release of VD3 in both PBS medium and simulated gastrointestinal tract. Photostability against UV light was significantly improved after encapsulation. Encapsulation of hydrophobic nutrients in zein nanoparticles with CMCS coatings is a promising approach to enhance chemical stability and controlled release property.     

茶多酚对淀粉酯纳米颗粒及其稳定的Pickering乳液性质的影响

为探究茶多酚（Tea Polyphenols, TPs）对辛烯基琥珀酸酐（Octenyl Succinic Anhydride, OSA）酯化淀粉纳米颗粒（Starch Nanoparticles,SNPs）及其稳定的Pickering乳液性质的影响,该研究在制备OSA-SNPs的过程中添加TPs,研究TPs对OSA-SNPs的理化性质和乳化性能的影响。结果发现,添加TPs使OSA-SNPs的平均粒径增加、表面Zeta电位绝对值下降、接触角减小（P<0.05）。通过傅立叶红外光谱扫描发现,TPs与OSA-SNPs之间存在氢键和疏水相互作用。在TP-OSA-SNPs稳定的乳液中,增加TP-OSA-SNPs的质量浓度（从0.5 g/mL至2.0 g/mL）,乳滴平均直径明显减小（P<0.05）;当TP-OSA-SNPs的质量浓度增加至2 g/mL时,乳液形成了油滴紧密堆积的界面结构,能够抑制油滴迁移。通过加速氧化试验发现,与OSA-SNPs相比,TP-OSA-SNPs稳定的乳液中氢过氧化物值（Peroxide Value, POV）相对较低（P<0.05）,说明TP-OSA-SNPs具有延缓乳液中油脂氧化的作用。结果表明,这种新型具有抗氧化功能的食品级颗粒乳化剂,对构筑淀粉基Pickering乳液载体具有潜在价值。