三聚甘油脂肪酸酯对甘油二酯结晶特性的影响

甘油二酯(Diacylglycerol,DAG)是一种功能性油脂,可作为潜在的食品专用油脂,故对其结晶特性的研究具有重要的理论意义。在鼓泡式反应器无溶剂体系中,利用脂肪酶Lipozyme 435催化硬脂酸、油酸与甘油酯化反应制备甘油二酯。酯化产物经分子蒸馏纯化得到含量为78.39 wt%的甘油二酯。利用差示扫描量热仪、脉冲核磁共振仪、X射线衍射仪和偏光显微镜考察两种三聚甘油脂肪酸酯(Polyglycerol fatty acid ester,PGFE)对甘油二酯结晶特性的影响。结果表明,硬脂酸三聚甘油酯(PGFE1)对甘油二酯具有促进结晶作用;亚油酸三聚甘油酯(PGFE2)对甘油二酯具有抑制结晶作用,当PGFE2的含量由2%增加为10%时,其抑制作用变大。X射线衍射结果显示PGFE1对甘油二酯β′型晶型有稳定作用。偏光显微镜观察到PGFE1的添加使甘油二酯的晶体变得更为细腻。     

聚甘油脂肪酸酯对可可脂结晶特性的影响

可可脂(CB)是巧克力及巧克力制品的主要成分,其热力学及结晶特性决定了产品的品质、加工特性和货架期。以聚甘油单硬脂酸酯31S、61S和聚甘油蓖麻醇酯(PGPR)为研究对象,利用差示扫描量热(DSC)和X射线衍射技术,研究乳化剂种类、添加量、变温条件对可可脂结晶特性的影响。研究发现:调温温度下,31S和61S具有促进可可脂结晶从Ⅳ型向Ⅴ型转变的效果;而PGPR在添加量大于0.1%的情况下,则表现出对Ⅳ型向Ⅴ型转变的抑制效果;在变温条件下,31S和61S具有促进可可脂热力学亚稳定态晶型的形成和晶型转换的效果,特别是促进了可可脂Ⅱ型晶型的形成,而PGPR无显著影响。     

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。     

聚甘油脂肪酸酯结构对姜黄素纳米乳液稳定性及其功能特性的影响

使用聚甘油脂肪酸酯(polyglycerol fatty acid esters,PGFEs)制备姜黄素纳米乳液,并探究PGFEs的脂肪链长(C10～C18)对姜黄素纳米乳液的乳液特性、贮存稳定性、抗氧化活性及抗菌活性的影响.结果表明:PGFEs脂肪链长的增加会使乳液粒径增大、Zeta电位变低,但不影响姜黄素的包封效率...     

Synthesis of fluorescent ABA triblock copolymer via click reaction

A hyperbranched–linear–hyperbranched (ABA) triblock copolymer containing poly(ethylene glycol) (PEG) as linear block and polyglycerol (hbPG) as hyperbranched blocks has been synthesized through a copper‐catalysed click reaction. In order to synthesize the hyperbranched block, propargyl alcohol‐initiated ring‐opening multibranching polymerization of glycidol was used to prepare hbPG with the propargyl segment in the focal point (CH?C? hbPG). Separately, PEG was functionalized at both ends using cyanuric chloride, and then the chloride groups of cyanuric chloride were substituted by azide groups. Finally, the azide‐functionalized PEG was conjugated to CH?C? hbPG via a click reaction. Substitution of the chlorine atoms of cyanuric chloride under different conditions together with click chemistry allows the synthesis of a variety of polymeric architectures. In the last step, fluorescein was attached to the block copolymer as a fluorescent probe in order to study the cell internalization of this copolymer. This type of triblock copolymer is a promising future nanomaterial for simultaneous drug delivery and cell imaging. © 2016 Society of Chemical Industry     

Lipid‐based fat substitutes

Fats and oils account for 38% of the total calories in the diet of Western populations, especially in the U.S. They provide the most concentrated source of energy, 9 kcal/g of a triacylglycerol molecule compared with 4 kcal/g provided by carbohydrate and protein. In response to consumer demands for low‐calorie or calorie‐free fats and their reluctance to give up the taste of fat, current research efforts have been directed toward the development of lipid‐like fat substitutes. These fat substitutes contain the fatty acids found in conventional fats and oils, with all the physical and organoleptic properties of fats, but provide few or no calories in the diet. Some of the fat substitutes are modified triacylglycerols (glycerol backbone) with reduced digestion and absorption; others are digestible and nondigestible carbohydrate fatty acid esters and polyesters, respectively. Sucrose polyester (Olestra^®), a sucrose molecule esterified with six to eight fatty acids, is the most studied of the lipid‐based fat substitutes containing a carbohydrate backbone. If approved by the FDA, sucrose polyester will find application in almost all fat‐containing foods. Specialty fats or fat substitutes targeted to certain individuals with special needs are being developed. Among these are the medium‐chain triacylglycerols and structured lipids (glycerol backbone), or “nutraceuticals” with reduced absorption and medical applications. Enzyme biotechnology is another tool available to lipid chemists to selectively modify, esterify, transform, transesterify, and interesterify fats and oils or synthesize new lipids such as structured lipids of food, nutritional, and medical importance. These designer fats may be the trend in the future to produce medical lipids that do not occur normally in nature. The different types of lipid‐based fat substitutes are reviewed with respect to their synthesis, analysis, metabolism, potential applications/uses, and the future of fat substitutes.     

聚甘油脂肪酸酯QSPR的研究

采用量子化学MOPAC-AM1和单点能方法计算聚甘油脂肪酸酯的分子结构参数,然后用逐步线性回归方法建立聚甘油脂肪酸酯HLB值的定量结构性质(QSPR)模型,所得的预测模型中包含4个参数[单位质量分子所含氧原子数Xo、生成热fHm、电子能Ee和水合能Eh,预测值及外部检验的复相关系数(R2)和标准偏差(SD)分别为0.9553、0.73722和0.9678、6.34426。结果表明,量子化学方法计算简单,对聚甘油脂肪酸酯结构的表征能力较强,所建定量结构性质模型具有能较好的预测能力和较强的稳健性,并在一定程度上阐明了聚甘油脂肪酸酯HLB值与其分子结构之间的关系。     

聚异丁烯丁二酸聚甘油酯的制备及其性能研究

以聚异丁烯丁二酸酐、聚甘油为原料,制备了标题化合物,并用红外光谱对其进行结构表征。测定了产品的极限乳化性能与储存稳定性能,结果表明,产品的极限乳化性能与储存稳定性能均优于聚异丁烯丁二酰亚胺(T152),适用于乳化炸药行业;并且测定了产品的分散性能,结果表明产品的分散性能优于聚异丁烯丁二酰亚胺(T154),适用于润滑油行业。产品的成本明显低于聚异丁烯丁二酰亚胺(T152,T154)的成本,具有很好的推广前景。     

Hyperbranched–linear–hyperbranched ABA‐type block copolymers based on poly(ethylene oxide) and polyglycerol

BACKGROUND: Until recently, hyperbranched polymers were thought to be ill‐defined materials that were not useful as building blocks for well‐defined complex polymer architectures. It is a current challenge to develop strategies that offer rapid access to well‐defined hyperbranched block copolymers. RESULTS: A convenient three‐step protocol for the synthesis of double‐hydrophilic hyperbranched–linear–hyperbranched ABA‐type triblock copolymers based on poly(ethylene oxide) (PEO) and hyperbranched polyglycerol (hbPG) is presented. The Bola‐type polymers exhibiting an aliphatic polyether structure were prepared from a linear (lin) linPG‐b‐PEO‐b‐linPG precursor triblock. The materials exhibit low polydispersities (M_w/M_n) in the range 1.19–1.45. The molecular weights of the block copolymers range from 6300 to 26 200 g mol^?1, varying in the length of both the linear PEO chain as well as the hbPG segments. Detailed characterization of the thermal properties using differential scanning calorimetry demonstrates nanophase segregation of the blocks. CONCLUSION: The first example of well‐defined ABA hyperbranched–linear–hyperbranched triblock copolymers with PEO middle block and hbPG A‐blocks is presented. The biocompatible nature of the aliphatic polyether blocks renders these materials interesting for biomedical purposes. These new materials are also intriguing with respect to their supramolecular order and biomineralization properties. Copyright © 2009 Society of Chemical Industry