中链脂肪酸脂质体的制备及其性质测定

以卵磷脂和胆固醇为膜材,中链脂肪酸(MCFAs)为油溶性模型材料,采用薄膜分散- 动态高压微射流法(薄膜分散-DHPM法)及动态高压微射流- 冻融法(DHPM- 冻融法)制备MCFAs 脂质体,以包封率和平均粒径为主要考察指标对两种方法进行比较。结果表明：薄膜分散-DHPM 法最佳制备条件为脂质质量浓度8g/100mL、磷脂与胆固醇质量比5:1、处理压力140MPa、处理次数4 次;DHPM- 冻融法最佳制备条件为冷冻时间0.5h、融化温度40℃、冷冻保护剂为麦芽糖、冷冻保护剂用量3%。最佳条件下,薄膜分散-DHPM 法制备的MCFAs 脂质体平均粒径为87.1nm,分布均匀,包封率可达(66.5 ± 3.1)%;DHPM- 冻融法制备的MCFAs 脂质体粒径较大,平均粒径为110.1nm,包封率较低,为(53.5 ± 4.9)%。通过MCFAs 脂质体泄漏动力学和精密度(日间和日内)实验考察其稳定性。薄膜分散-DHPM 法和DHPM- 冻融法的稳定性都较好,均适合于MCFAs 脂质体的制备。     

中链脂肪酸脂质体的制备及其特性评价

采用薄膜蒸发-超声法制备中链脂肪酸脂质体,考察单因素制备工艺对包封率的影响以及所得脂质体的外观形态、粒径、Zeta电位和稳定性。结果表明,中链脂肪酸脂质体的最佳工艺条件为:磷脂与胆固醇之比为3:1,中链脂肪酸与总脂材比为1:10,表面活性剂(吐温-80)与膜材之比为3:10,制备温度为35℃。最佳工艺条件下产物包封率可达82.9%,平均粒径为240.420.3nm,Zeta电位为-52.273.2mV,4℃下放置90d质量稳定。     

大豆磷脂维生素E脂质体的制备

采用复乳法,利用大豆粉状高纯磷脂制备维生素E脂质体。研究了维生素E脂质体配方中不同成分的比例、制备条件对脂质体包封率的影响。结果表明,用复乳法获得维生素E脂质体的最佳制备条件为:温度46℃,粉状混合磷脂加入量为2.5g,维生素E∶磷脂为1∶25(wt/wt),胆固醇的量为0.25g,维生素E与胆固醇比为1∶2.0(wt/wt),体积比为2∶1的三氯甲烷/甲醇混合有机溶剂为80mL(1g维生素E对应1200mL体积比为2∶1的三氯甲烷/甲醇混合有机溶剂),在此条件下,维生素E的包埋率为75%。     

大豆磷脂维生素E脂质体的制备

采用复乳法,利用大豆粉状高纯磷脂制备维生素E脂质体。研究了维生素E脂质体配方中不同成分的比例、制备条件对脂质体包封率的影响。结果表明,用复乳法获得维生素E脂质体的最佳制备条件为:温度46℃,粉状混合磷脂加入量为2.5g,维生素E∶磷脂为1∶25(wt/wt),胆固醇的量为0.25g,维生素E与胆固醇比为1∶2.0(wt/wt),体积比为2∶1的三氯甲烷/甲醇混合有机溶剂为80mL(1g维生素E对应1200mL体积比为2∶1的三氯甲烷/甲醇混合有机溶剂),在此条件下,维生素E的包埋率为75%。      

维生素C脂质体的制备

用薄膜法制备维生素C脂质体,以大豆卵磷脂和胆固醇为基本材料,分别加入N,N-双十六烷胺和聚乙二醇,研究不同配比的维生素C脂质体在室温和冷藏条件下的包封率和稳定性。结果表明,常规脂质和加入N,N-双十六烷胺、聚乙二醇辅料制得的维生素C脂质体的最大包封率分别为16.72%、17.91%、17.58%。加入聚乙二醇后,脂质体的稳定性得以提高。冷藏条件下保存的脂质体的稳定性要高于室温。     

中链脂肪酸-VC复合脂质体制备及初步稳定性

以磷脂和胆固醇为膜材,脂溶性的中链脂肪酸(MCFAs)和水溶性的VC为模型药物,以脂质体的包封率和粒径为指标,分别采用薄膜法、复乳法、薄膜-高压法、复乳-高压法制备中链脂肪酸-VC复合脂质体,筛选出最佳制备方法(复乳-高压法),并通过单因素试验设计,确定复合脂质体的最优处方工艺为:总脂材质量浓度5.0g/100mL,MCFAs质量浓度10.0mg/mL,VC质量浓度3.0mg/mL,卵磷脂与胆固醇质量比为4:1,卵磷脂质量与无水乙醇体积比为1:10(g/mL),吐温与总脂材质量比为3:10,VE与卵磷脂质量比为4:100,120MPa条件下超微乳化处理2次。制备的复合脂质体MCFAs包封率达到49.01%,VC的包封率达到54.19%,平均粒径90.3nm,在4℃贮藏15d,包封率和粒径变化不大,表明脂质体低温贮藏稳定性良好。     

pH梯度法制备维生素C脂质体

制备维生素C脂质体,并考察其包封率的影响因素。采用pH梯度法制备维生素C脂质体,以紫外分光光度法和粒度仪分别测定脂质体的包封率和粒径,并考察外水相pH、超声时间、载药温度及药脂比对包封率的影响。结果显示包封率随外水相pH的降低而增加,最佳超声时间为15 min,随着载药温度的增加包封率有提高的趋势,最佳药脂比为1∶5。该条件下pH梯度法制备的维生素C脂质体的包封率为(49.79±1.6)%(n=3),平均粒径为(118.3±9.6)nm。     

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。     

不同因素对中链脂肪酸脂质体Zeta电位的影响

Zeta电位值是评价脂质体稳定性的重要指标。在前期对中链脂肪酸脂质体研究的基础上,考察磷脂种类、脂质质量浓度、表面活性剂吐温-80添加量、不同pH值、不同金属离子种类及浓度对中链脂肪酸脂质体Zeta电位的影响。结果表明:选用大豆卵磷脂,脂质质量浓度为8g/100mL,吐温-80与磷脂质量比为3:10时制备的中链脂肪酸脂质体Zeta电位的绝对值最高,为51.08mV;中链脂肪酸脂质体的Zeta电位绝对值随环境阳离子价电数、环境离子浓度的增加均逐渐减小;中链脂肪酸脂质体在偏中性(pH7、8)环境下最稳定,其Zeta电位绝对值为50mV左右,而在强酸(pH1、2)、强碱(pH13)性环境下,其Zeta电位值趋近于0mV,最不稳定。     

W/O型中链脂肪酸微乳的制备及其性质的测定

以中链脂肪酸(MCFA)为原料,用HLB值法制备的W/O型中链脂肪酸(MCFA)微乳,可提高油溶性药物或营养物的溶解性和生物利用率.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;通过乳化效率、伪三元相图和反应过程中的现象,得到制备W/O型MCFA微乳的最适HLB值为4.7,最佳表面活性剂为单独使用司盘60,最佳助表面活性剂为异丙醇,最优配方为m司盘60:m异丙醇:mMCFA:m蒸馏水=1:2:3:0.5.考察优化配方的理化性质,初步稳定性良好,表面张力可达到25.50 mN/cm,粘度50.06 cP,电导率3.31 μs/cm,粒径20.1±3.3 nm,zeta电位-6.23 mV.     

原花青素乳液及其微胶囊制备技术研究

以原花青素为芯材,用高压微射流技术结合喷雾干燥制备原花青素乳液及其微胶囊。采用高压微射流处理原花青素乳液,选取阿拉伯胶和β-环糊精作为壁材,以壁材中阿拉伯胶含量、乳化剂用量、总固形物含量、处理压力为影响因素,以乳液的Zeta电位为指标进行研究。在单因素的实验基础上,通过响应面优化分析可知最佳优化工艺为:阿拉伯胶含量为40%、总固形物含量为15%、处理压力为160 MPa。在最优条件下制备的乳液经喷雾干燥后,微胶囊的包埋产率为98.20%,包埋效率为88.60%。同时采用红外光谱进行表征,结果表明原花青素包埋前后某些色谱峰的峰强存在差异,需要进一步分析高压微射流处理对原花青素性质的影响。      

Vc纳米脂质体的制备研究

以大豆卵磷脂和胆固醇为膜材,采用薄膜蒸发-动态高压法制备Vc纳米脂质体.通过单因素考察处方工艺对包封率的影响以及正交设计法进行处方工艺优化.结果表明,制备Vc纳米脂质体的最优条件:制备温度60℃,Vc浓度5mg/mL,Vc和总脂材质量比为1∶10,大豆卵磷脂和胆固醇质量比为4∶1,表面活性剂和总脂材质量比为4∶10,动态高压处理压力为140MPa,处理2次.该条件下包封率可达(47.16±6.28)％,平均粒度为(73.9±4.4)nm.     

Effect of partially defatted coconut flour on the rheological,physico-sensory characteristics and fatty acid profile of no-added fat rusk

Partially defatted coconut flour (PDCF) as a source of medium chain fatty acids was selected to replace fat in rusk formulation. Effect of replacement of wheat flour with PDCF (10%, 20% and 30%) on quality characteristics of rusk was studied. Increasing PDCF from 0% to 30% decreased farinograph water absorption, amylograph peak viscosity and overall quality score (52.5 to 19.5) of rusk. Use of additive mix, AM (4% dry gluten powder + 0.002% fungal α-amylase) to 20% PDCF, increased the farinograph dough stability, strength of the paste during heating and overall quality score (39.5 to 50.5). The rusk with 20% PDCF + AM was stable up to 30 days, had 1.6, 5.5 times higher protein and dietary fibre contents as compared to control rusk respectively. The fat in the rusk had zero trans fatty acids and contained 66.2% medium chain fatty acids with lauric acid as a major fatty acid.     

固体碱催化合成中碳链脂肪酸聚甘油酯

以聚甘油、樟树籽仁油脂肪酸为原料,固体碱KOH/Al2O3为催化剂,催化酯化合成中碳链脂肪酸聚甘油酯.采用单因素试验研究反应温度、反应时间、聚甘油与中碳链脂肪酸质量比、催化剂用量对酯化率的影响,通过正交试验优化中碳链脂肪酸聚甘油酯的合成工艺.最优合成工艺条件为反应温度220℃、反应时间2.5h、聚甘油与中碳链脂肪酸质量比2∶1、催化剂用量4.5％,该条件下酯化率为87.5％,所得中碳链脂肪酸聚甘油酯的酸值(KOH)、皂化值(KOH)、碘值(Ⅰ)、熔点分别为1.86 mg/g、148.4 mg/g、2.9 g/100 g、47.3℃.     

支链脂肪酸及其抗炎作用研究进展

支链脂肪酸主要是饱和脂肪酸,在其碳骨架上有1个或多个支链,支链以甲基最为常见。特殊的支链结构和饱和状态使支链脂肪酸具有独特的理化性质。支链脂肪酸与炎症关系密切,目前我国对于支链脂肪酸的研究大多还集中于牛羊类反刍动物的乳汁、肉制品上,对于与人类相关支链脂肪酸的研究还很少。综述了支链脂肪酸的结构及其分布特征,总结了支链脂肪酸的主要生理功能与机制,探究了人乳、喂养方式、新生儿坏死性小肠结肠炎与支链脂肪酸的关系。提出开发支链脂肪酸作为孕妇的膳食补充剂,或以支链脂肪酸为原料发展新型抗癌药是未来的研究方向。     

酶法催化制备含有中链及中长链脂肪酸的甘油二酯及性质表征

采用富含棕榈酸和硬脂酸的分子蒸馏单甘酯(MAG)和癸酸为原料,以Novozyme 435酶为催化剂,通过酯化反应制备富含中链脂肪酸及中长链脂肪酸的甘油二酯(DAG)(含有中链脂肪酸甘油二酯(MCD)和中长链脂肪酸甘油二酯(MLCD))。通过单因素试验探究了底物摩尔比(癸酸与MAG摩尔比)、反应温度、反应时间、加酶量对产品中DAG含量的影响,利用气相色谱仪(GC)、差示扫描量热仪(DSC)、脉冲核磁共振仪(p-NMR)、X-射线衍射仪(XRD)和偏振光显微镜(PLM)分析手段,研究DAG产品的脂肪酸与甘油酯组成、热力学性质、固体脂肪含量、结晶特性等。最终所选工艺条件为:底物摩尔比1∶1,反应温度65℃,反应时间35 min,加酶量5%。在所选择的工艺条件下,DAG含量为(37.3±0.1)%,其中MCD含量和MLCD含量分别为(7.28±0.1)%和(30.02±0.1)%,DAG和甘油三酯(TAG)的含量比为9.8∶1;固体脂肪含量表明产品具有一定的可塑性,通过晶型和晶体微观形态分析,DAG主要为β晶型。研究结果可为后续相关产品的开发提供基础理论依据。     

Preparation of palm olein enriched with medium chain fatty acids by lipase acidolysis

Medium chain (MC) fatty acids, caprylic (C8:0) and capric (C10:0) were incorporated into palm olein by 1,3-specific lipase acidolysis, up to 36% and 43%, respectively, when added as mixtures or individually after 24 h. It was found that these acids were incorporated into palm olein at the expense of palmitic and oleic acids, the former being larger in quantity and reduction of 18:2 was negligible. The modified palm olein products showed reduction in higher molecular weight triacylglycerols (TGs) and increase in concentration of lower molecular weight TGs compared to those of palm olein. Fatty acids at sn-2 position in modified products were: C10:0, 4%; C16:0, 13%; C18:1, 66%; and C18:2, 15.4%. DSC results showed that the onset of melting and solids fat content were considerably reduced in modified palm olein products and no solids were found even at and below 10 °C and also the onset of crystallisation was considerably lowered. The cloud point was reduced and iodine value dropped from 55.4 to 38 in modified palm olein. Thus, nutritionally superior palm olein was prepared by introducing MC fatty acids with reduced palmitic acid through lipase acidolysis.     

Influence of wax type on characteristics of oleogels from camellia oil and medium chain triglycerides

Camellia oil (CO) and medium chain triglycerides (MCTs), characterised by different carbon chain lengths, were gelled using beeswax (BW), candelilla wax (CLW) and carnauba wax (CRW). Critical concentrations, oil-binding capacity (OBC), textural parameters, thermal properties, microscopic properties and infrared spectra were used to evaluate their differences. The carbon chain length of oil sources showed different results for the critical concentration of the three wax-based gel oils at 25 °C, and the oleogel of MCT and CLW exhibited a minimum value (1%). The oleogels formed from CO and waxes with wax esters as the main components (BW and CRW) exhibit significantly lower OBC and textural value than the oleogels made from MCT with BW and CRW. Meanwhile, this is corroborated with the thermal behaviour and crystal morphology, and distribution of the oleogels. However, no differences in crystal types and generation of new functional groups were observed by X-ray diffraction and Fourier-transform infrared spectrometer, suggesting that the differences in the properties of wax-based oleogels with different carbon chain lengths are attributed to the interactions between the waxes and the oil sources (physical interaction).     

羊奶短中链脂肪酸与羊奶膻味关系的研究

采用气相色谱法(GC)对18个羊奶样品中短中链游离脂肪酸(FFA)和短中链结合脂肪酸(CFA)组成进行检测,并对游离脂肪酸(FFA)和结合脂肪酸(CFA)与羊奶膻味强度进行相关性分析。结果表明,在羊奶短中链脂肪酸中,游离脂肪酸是引起羊奶膻味的主要因素,其中己酸(C6∶0)、辛酸(C8∶0)和癸酸(C10∶0)与羊奶膻味强度呈极显著相关(p<0.01),是引起羊奶膻味的主要游离脂肪酸(FFA);肉豆蔻酸(C14∶0)和棕榈酸(C16∶0)与羊奶膻味强度呈显著性相关(p<0.05),也对羊奶膻味有一定的贡献。结合态脂肪酸与羊奶膻味强度不显著(p>0.05),与羊奶膻味关系不大。