Optimization of Wax Esters Production from Palm Fatty Acid Distillate and Oleyl Alcohol over Amberlyst 15

Wax esters were derived from long chain fatty acids and long chain alcohols with chain length of 12 carbons or more. These compounds have many potential applications in cosmetics, pharmaceuticals and food industries. The present work focuses on the synthesis of wax esters using palm fatty acid distillate and oleyl alcohol catalyzed by Amberlyst 15. Response surface methodology （RSM） based on a five-level, three-variable central composite design （CCD） was used to evaluate the interactive effects of synthesis, of amount of Amberlyst 15 catalyst （21.6-38.4% w/w）, reaction time （18-102 min） and molar ratio （palm fatty acid distillate to oleyl alcohol, 1：1.16-1：2.84） on the percentage conversion of palm fatty acid distillate. The optimum conditions derived via RSM were： amount of catalyst 33% w/w, reaction time 95 minute and palm fatty acid to oleyl alcohol molar ratio 1：2.7. The actual experimental conversion was 81.52% under optimum condition, which compared well to the maximum predicted value of 80.50%. Analysis of the yield showed that at optimum condition, 80.54% wax esters were produced.

Emulsification Properties of Lactose Fatty Acid Esters

Sugar fatty acid esters (SFAE) are a class of synthetic emulsifiers used in the food, pharmaceutical, and personal care industries. The influence of the fatty acid chain length on the emulsification properties of lactose fatty acid esters (LFAE) including lactose monooctanoate (LMO), lactose monodecanoate (LMD), lactose monolaurate (LML) and lactose monomyristate (LMM) was investigated in this study. The stability of the emulsions as well as the oil droplet size distribution in 20% soybean oil-in-water emulsions was measured at 0.1%, 0.25% and 0.5% of LFAE concentrations. In order of LFAE with the strongest emulsion stabilization characteristics were LML, LMD, LMO and LMM. Oil droplet distributions resulted in the same trend, with LML and LMD maintaining the smallest droplet sizes and thus the most stable emulsion. The hydrophilic-lipophilic balance (HLB) and critical micelle concentrations were determined for each LFAE. An increase in HLB value was seen with an increased CMC value for each LFAE, showing the strength of the linear relationship between these two measured values. Additionally, there was a decrease in HLB and CMC values with a decrease in the fatty acid chain length of each LFAE. This research showed that LML and LMD formed more stable emulsions, even with HLB and CMC values higher than those of LMM suggesting HLB and CMC values alone do not predict emulsifier effectiveness.

Lipids and fatty acids in Calanus sinicus during over-summering in the southern Yellow Sea

Over-summering is a crucial period for Calanus sinicus in the southern Yellow Sea,where it is a key member of the zooplankton community.Lipids play an important role in copepod diapause,which is part of their over-summering strategy.We investigated how different fatty acids and lipid classes,including wax esters,changed during over-summering of C.sinicus during three cruises in June and August 2011 and November 2010,corresponding to the pre-,during and post-diapause periods,respectively.Large amounts of lipids were accumulated,mainly wax esters as previously found in C.finmarchicus during its diapause,and most of the storage lipids were used during over-summering.Wax ester polyunsaturated fatty acids(PUFAs) showed the most variation of the fatty acids(FAs),while the percentage composition of FAs in polar lipids was relatively stable.Selective use of wax ester PUFAs has already been shown to play important roles in the winter diapause of Calanus species in other regions,and our FA results show that this is the case for the Yellow Sea Cold Bottom Water(YSCBW) population that diapauses in summer.

Factors aff ecting lipid and fatty acid composition of Calanus sinicus in the Yellow Sea and the East China Sea in spring

The factors aff ecting lipid and fatty acid composition of copepod Calanus sinicus in the Yellow Sea(YS)and the East China Sea(ECS)were examined in this study.In spring,there were signifi cant diff erences between these two regions for both environmental conditions and food availability.Such regional diff erence signifi cantly infl uenced the lipid and fatty acid profi les of C.sinicus.Our results show that C.sinicus has a higher lipids content in ECS,especially for wax ester and triglyceride lipids,indicating a more active and effi cient predation.According to BIO-ENV analysis,the variation of lipids profi les may be infl uenced majorly by water temperature.Moreover,the fatty acids(FAs)profi les of C.sinicus were also diff erent between YS and ECS,especially in the four major contributors,C22꞉1ω11,eicosapentaenoic acid(EPA),docosahexenoic acid(DHA),and C20꞉1ω9.The considerable amounts of self-biosynthesized FAs of herbivorous copepod(C22꞉1ω11 and C20꞉1ω9)and low DHA/EPA ratio may indicate that C.sinicus in ECS feed mainly on phytoplankton comparing to those in YS.The fatty acid profi les of C.sinicus were aff ected by the diff erences in food availability.

表面活性剂对葵蜡油凝胶性能的影响

本文以表面活性剂聚甘油-10油酸酯(Polyglycerol-10 Oleate,PG-10)、聚甘油蓖麻醇酸酯(Polyglycerol Polyricinoleate,PGPR)以及葵蜡(Sunflower Wax,SW)为材料,制备聚甘油脂肪酸酯-SW油凝胶,研究PG-10和PGPR添加量对油凝胶性能的影响。结果表明,PG-10和PGPR的添加均会影响SW油凝胶的结晶性能及持油能力。随着PG-10添加量的增大,油凝胶晶体数量减少,持油能力下降。而PGPR在低浓度下(0.3%~1.0%)的添加使得油凝胶结构的持油能力增强,这可能与其较低的亲水亲油平衡值(Hydrophilic Lipophilic Balance,HLB)有关。本研究有助于为其在食品或化妆品中应用构建多组分脂质相提供有益参考。

水菱钇型碳酸钕的形成及聚甘油脂肪酸酯对结晶的影响

Amorphous Neodymium carbonate was prepared by the precipitation reaction of neodymium chloride with ammonium bicarbonate in solution, and then aged at 60 ℃ to form crystalline neodymium carbonate. The feed molar ratio of nNH4HCO3/nNdCl3 was 2.5, and the precipitation was carried out with or without addition of polyglyceryl fatty acid ester (PGFAE). The phase type and morphology of crystalline neodymium carbonates were examined by XRD and SEM, and the effect of PGFAE on the crystallization speed was investigated by volume change in deposit layer and in situ pH determination. The content of neodymium and chloride in crystals was analyzed, and the crystallization reaction or crystal growth characteristics were discussed. It was found that all the crystalline neodymium carbonates were tengerite type, and contained less crystalline water and chloride than that of lanthanite type neodymium carbonate crystallized at room temperature, which is beneficial to the production of neodymium carbonate with higher neodymium and lower chloride content. The addition of PGFAE not only could eliminate the foam formed during precipitation, but also could shorten crystallization time, and form large radiative-like shape conglomeration by the irregulative linkage of one dimension needle crystals. It is also suggested that the morphology and the chloride content of neodymium carbonate were dependent on the structure and crystal growth characteristics.

酶催化法合成食品乳化剂的研究进展

食品乳化剂是现代食品工业不可或缺的添加剂。与化学合成法相比,酶催化法合成食品乳化剂具有很多优势,如催化效率高、反应条件温和、产品纯度高、色泽浅且容易分离纯化等。本文介绍了脂肪酸单甘酯、脂肪酸糖酯、丙二醇脂肪酸酯以及失水山梨醇脂肪酸酯四类常用食品乳化剂的酶催化法合成研究进展,对酶催化合成方法、反应媒介的选择及存在的主要问题等方面进行了综述。

3种色谱柱对37种脂肪酸的分离性能比较及鱼油脂肪酸检测

利用气相色谱-质谱联用技术,考察HP-5、DB-Wax和SPB-50三种不同极性色谱柱对37种脂肪酸甲酯(fattyacid methy ester,FAME)混标的分离性能,并对实际鱼油样品的脂肪酸进行检测。结果表明:3种色谱柱都能用于FAME的分析,低碳数的物质最先出峰,同碳数而饱和度不同的FAME在不同固定相上的出峰顺序不同;与其他两种色谱柱相比,SPB-50柱能分离出顺式和反式异构体以及有效分离ω-3与ω-6系列脂肪酸,更适合检测复杂的FAME混合物样品,特别是对顺式和反式脂肪酸以及ω-3(如EPA和DHA)和ω-6等功能性脂肪酸的检测有重要意义。

漆蜡脂肪酸甲酯磺酸盐的制备及其性能研究

以漆蜡为原料,经甲酯化后以氯磺酸为磺化剂,双氧水为漂白剂制备漆蜡脂肪酸甲酯磺酸盐,研究了最佳制备工艺条件,并对漆蜡脂肪酸甲酯磺酸盐的性能进行了研究。试验得到漆蜡脂肪酸甲酯磺酸盐最佳制备工艺条件为:漆蜡脂肪酸甲酯与氯磺酸摩尔比1∶1.2,磺化时间40 min,老化时间45 min;在最佳制备工艺条件下的漆蜡脂肪酸甲酯磺酸盐含量最高,为40.1%,二钠盐含量为18.5%;经纯化后,漆蜡脂肪酸甲酯磺酸盐含量为78.0%,二钠盐含量为3.2%。漆蜡脂肪酸甲酯磺酸盐临界胶束浓度为0.7×10-3mol/L,表面张力为39 mN/m;在其水溶液质量分数为0.1%时,分出5 mL水的时间为60 s;漆蜡脂肪酸甲酯磺酸盐的发泡能力为65 mm,静置5 min后,泡沫高度降为50 mm。

影响卷烟烟气柔和性的主要化学成分分析及柔和性功能香精的开发

为了提升卷烟烟气柔和性,改善卷烟抽吸品质,采用GC-MS方法,对烟丝的化学成分、卷烟烟气成分进行测定,并对它们与卷烟烟气柔和性的相关性进行分析。结果表明:①糖氮比值高的,刺激较小,烟气柔和性较好;②游离烟碱含量高,劲头大,对喉部的冲击感较强,柔和性较差;③烟叶致香成分中新植二烯和高级脂肪酸酯含量、主流烟气粒相水分与卷烟柔和性存在正相关。以此为指导,利用天然植物原料及其提取物,开发了提高卷烟烟气柔和性的功能性香精,并将其应用于卷烟产品,对比评吸结果表明,添加了柔和性功能香精的卷烟产品,柔和性得分平均提高1.5～2分。

脂肪酶催化合成生物表面活性剂

脂肪酸单甘油酯、脂肪酸糖酯、聚甘油脂肪酸酯和长链脂肪酸蜡酯是重要的生物表面活性剂。传统化学法以碱为催化剂在高温下进行 ,不仅能耗高且产品纯度低。脂肪酶作为一种天然生物催化剂 ,可在温和条件下催化合成上述生物表面活性剂 ,能耗低且产品纯度高。综述对脂肪酶催化合成生物表面活性剂工艺路线、反应体系及操作参数。

糖酯酶促合成及抗真菌活性的初步研究

研究了糖酯对食品中腐败真菌的抗菌作用。以脂肪酶作为催化剂,采用丙酮-分子筛体系进行反应,经硅胶柱层析法分离纯化制备得到糖酯。分别测定几种糖酯在不同pH值条件下对草酸青霉、塔宾曲霉、卷枝毛霉和黑根霉的抗菌效果。结果表明,果糖月桂酸酯对草酸青霉和塔宾曲霉的抗菌作用最强,并随浓度的增大,其抗真菌活性也随之增强。果糖月桂酸酯除对供试真菌的菌落直径大小有影响外,还影响到了菌落薄厚和产色素情况,其抗菌活性受pH值影响较大,在中性条件下的抗真菌活性低于酸性和碱性条件。

乳化剂对米糠蜡凝胶油理化特性的影响

将单硬脂酸甘油酯、硬脂酰乳酸钠、聚甘油脂肪酸酯分别与米糠蜡复配制备凝胶油,研究乳化剂添加量对凝胶油持油率、晶体形态、热学性质、分子间作用力、晶型和流变学的影响。结果表明:乳化剂的复配质量比对凝胶油的微观结构和宏观特性都会产生影响,但对持油率和总焓变却不呈浓度依赖。随着单硬脂酸甘油酯含量的增加,α、β和β′3种晶型共存,晶体形态从针状转变为簇状,且表现出较好的流变性质。当单硬脂酸甘油酯与米糠蜡复配质量比为5∶2时,持油率高达87.94%。分子间作用力表明单硬脂酸甘油酯和聚甘油脂肪酸酯依靠氢键的键合作用增加液态油的束缚力和黏弹性质。

聚甘油酯对超声制备酪蛋白酸钠-米糠油乳液特性的影响

适宜的乳化剂组成对乳液的乳化特性有重要影响,本文重点研究了酪蛋白酸钠和聚甘油酯复配比例对超声制备米糠油乳液乳化特性的影响,从乳状液的界面蛋白吸附量、平均粒径及分布、黏度、乳析率、微观结构及低场核磁共振弛豫特性等方面进行分析。结果表明,随着聚甘油酯添加量的增加,乳状液的界面蛋白吸附量先增大后减小,平均粒径、乳析率减小,油滴分布更加均匀,黏度增大,且T_(2)弛豫时间变长,油滴流动性增加。当聚甘油酯添加量为0.2%~0.4%(W/W)时,会促进其与酪蛋白酸钠的相互作用,降低油水界面的表面张力,提升乳化特性。

体育用PGFE/PE防雾薄膜的制备及性能研究

利用聚甘油脂肪酸酯和聚乙烯蜡乳液对PE树脂进行改性处理,合成三聚甘油单硬脂酸酯(PGFE)/聚乙烯(PE)防雾薄膜。通过接触角测试及防雾性能测试等手段分析不同配比PGFE/PE薄膜在防雾性能和物理性能方面的差异。经试验分析发现,当聚乙烯蜡乳液(WE1)占比为0.5%、PGFE占比为2%时,PGFE/PE薄膜的综合性能较为理想,可用于体育防雾材料的加工制造。

聚甘油脂肪酸酯的合成应用与市场开发

本文介绍了聚甘油脂肪酸酯的组成、性能、合成工艺及其在食品乳化剂等领域的应用，指出了该产品广阔的发展前景。

半乳糖苷脂肪酸酯的选择性合成及其对Staphylococcus aureus和Salmonella agona的抗菌性

以甲基β-D-半乳糖苷为底物,用二丁基二甲氧锡作锡络合剂,脂肪酸酰氯作酰化剂选择性地合成半乳糖苷脂肪酸酯。最佳反应条件为:n(甲基β-D-半乳糖苷)∶n(二丁基二甲氧锡)∶n(脂肪酸酰氯)=1∶1.1∶1.1,温度为25℃,甲基3-O-脂肪酸酰基-β-D-半乳糖苷收率可达70%左右。并应用该糖酯类化合物作细菌Staphylococcusaureus和Salmonella agona的抗菌性测试,结果表明月桂酸酯和豆蔻酸酯分别使S.aureus的数量从5.322lgCFU/mL(空白)下降到3.441和3.563 lgCFU/mL;使S.agona的数量从6.094(空白)下降到3.813和3.830lgCFU/mL。

脂肪酶催化生物聚合研究进展

生物柴油是用动植物油脂或长链脂肪酸与甲醇等低碳醇合成的脂肪酸甲酯,是一种替代能源,脂肪酸单甘油酯、脂肪酸糖酯、聚甘油脂肪酸酯和长链脂肪酸蜡酯是重要的生物表面活性剂。传统化学合成方法以酸或碱为催化剂在高温下进行,能耗高,且产品纯度低。脂肪酶作为一种天然生物催化剂,可在温和条件下合成上述产物,能耗低且产品纯度高。综述了近年来脂肪酶催化生物合成的研究进展。

产蜡酯聚球藻PCC7002的构建

蜡酯是由含C16以上偶碳的高级脂肪酸与高级脂肪醇酯化形成的中性酯,是一种重要的经济油脂,被广泛应用于纺织、医药、化妆品和食品等行业。液态不饱和蜡酯还能作为航空航天工业、人工心脏、精密仪器仪表和特种机械等高科技领域专用的润滑剂。目前使用的蜡酯主要来源于动植物及矿石资源,来源十分有限,

润滑油中纳米铜粉聚甘油酯分散剂的合成与性能

为提高铜纳米颗粒在润滑油中的分散性能,以聚甘油和硬脂酸为原料合成了一系列聚甘油硬脂酸酯(PGFE)。通过沉降试验和流变性能的测试,考察了聚甘油的聚合度大小、硬脂酸含量等对分散性能的影响,通过热分析和红外光谱分析对分散剂吸附在铜粉表面的形态和性质做进一步考察。结果表明:当聚合度n=6、硬脂酸含量为65%时分散剂的分散性能良好,分散剂质量分数为1.5%时对流体流变性的影响最小,此时分散剂不仅有物理吸附还有化学吸附,并且极性酯基和羟基是影响吸附性能的主要官能团。