棕榈油氢化用Cu-Ni-Zn催化剂制备研究

通过正交实验确定Cu–Ni二元催化剂制备条件为:沉淀温度为60℃,陈化时间为80min,m(Cu)∶m(Ni)=1∶1,m(载体)∶m(活性物)=0.5∶1。用沉淀法制备不同Zn含量Cu–Ni–Zn三元催化剂,采用BET、TPR、XRD对制备Cu–Ni–Zn催化剂进行表征,考察Zn加入对棕榈油氢化用Cu–Ni二元催化剂活性和寿命影响。结果表明,适量Zn加入大大提高催化剂比表面积和孔容,促进活性成分在载体表面分散,从而提高催化剂活性及使用寿命。     

超声强化镍催化油脂共轭反应的研究

研究了超声强化镍催化剂催化油脂共轭反应的效果.在超声作用下,以大豆油为原料,镍为固体催化剂,氮气为保护气,通过单因素和正交实验,分别考察了超声功率、超声作用方式、反应温度、反应时间、催化剂用量等因素对油脂共轭反应的影响.结果表明最佳工艺条件为:超声功率25W,超声作用方式5 s/7 s,催化剂用量10％,反应时间50 min,反应温度140℃.在最佳工艺条件下得到油脂共轭亚油酸含量为7.498 mg/mL.     

碳载钯催化剂催化棕榈油连续化加氢反应研究

采用盐酸预处理活性炭,制备了适用于固定床反应器的颗粒状碳载钯催化剂。通过比表面积及孔结构、X射线衍射和透射电子显微镜分析表征手段,考察碳载钯催化剂在棕榈油连续化加氢反应体系中的催化性能。结果表明:碳载钯催化剂分散度高,粒径分布均匀,在棕榈油加氢反应中表现出了良好地催化CC加氢性能,在反应温度210℃、反应压力2.0 MPa和液时空速35 h-1条件下,氢化棕榈油碘值(I)可降至0.2 g/100 g以下;碳载钯催化剂还表现出较好的催化稳定性,在测试的100 h内没有明显失活迹象。     

高活性油脂加氢催化剂的制备

以硅酸钠和盐酸为原料制备载体多孔二氧化硅,以金属硝酸盐为前驱体,沉淀法制备油脂加氢催化剂,考察了制备方法,镍负载量,二氧化硅载体比表面积,催化剂助剂铁、钴等对催化剂活性的影响.结果表明:沉淀法效果优于浸渍法;最佳镍负载量为30％左右;二氧化硅载体的最佳比表面积为500～600 m2/g;最佳镍铁质量比为100∶1;创新采用钴助剂,镍钴最佳质量比仅为2 000∶1.镍钴复配催化剂具有制备过程简便,成本低廉,活性高等优点.     

Modified nano supported catalyst for selective catalytic hydrogenation of edible oils

We report an interesting finding that the catalytic performance of supported Ni/γ-Al₂O₃ catalyst towards selective catalytic hydrogenation of edible oils can be greatly enhanced by pretreatment of the γ-Al₂O₃ support before catalyst preparation. Calcination of Al₂O₃ at appropriate temperatures results in the highly dispersive nano Ni/γ-Al₂O₃ catalyst and thus improves the catalytic performance. Catalyst sample of improved physical properties prepared by modified procedure using γ-Al₂O₃ as support was characterized using powder XRD, SEM, BET, FTIR, Particle size analyzer, CO-chemisorption, and TPR studies. These studies indicate that support pretreatment results in enhancing catalyst dispersion with increase in Ni loadings. Clearly the effect of surface area and particle size of the catalyst coupled with surface properties and method of catalyst preparation on the saturated fats content of the foods like margarines prevails.     

两种Pricat镍催化剂对大豆油氢化中固脂和反式酸含量的影响

研究了两种Prieat镍催化刺在大豆油氢化过程中对固脂和反式酸含量的影响。结果表明，9908型催化荆适合油脂的选择性氢化，而9910型则适合植物油的极度氢化。详细探讨了9908型催化刺在不同氢化温度、氢气压力以及催化荆浓度下对氢化油固体脂肪含量以及反式脂肪酸的影响。结果表明，温度对氢化反应的异构化影响较大，氢气压力和催化剂浓度对异构化的影响相对较小。     

超细Ni粉催化剂制备及对油酸加氢条件的研究

用化学还原法制备超细镍粉，用扫描电镜对样品的微观结构进行了表征。以超细镍粉作为加氢催化剂，在高压反应釜中考察反应压力、温度、时间、催化剂用量等条件对油酸氢化效果的影响。结果显示，随着反应压力、温度的增加，加氢效果增强；而催化剂用量、反应时间对加氢效果影响较小。     

反式脂肪酸检测方法研究与应用

研究了甲醇钠-甲醇、氢氧化钾-甲醇、浓硫酸-甲醇和三氟化硼-甲醇4种甲酯化试剂的浓度、用量及甲酯化时间和温度对反式脂肪酸检测的影响,优化了色谱条件,建立了以三氟化硼-甲醇法甲酯化,RT-2560（100m×0．25mm×0．2μm）毛细管柱为基础的反式脂肪酸气相色谱检测方法,C18：1—9t,C18：1—11t,C18：2—9t,12t和C22：1—13t 4种反式脂肪酸的最小检出浓度在0．77—4．08mg／kg之间。4种反式脂肪酸不同添标浓度回收率为98．44％-101．23％,重复测定的相对标准差在0．22％-1．31％之间,有较好的准确度和重现性。应用该方法检测了武汉部分小型市场散装食用植物油和-些餐馆的废弃油脂,以所含脂肪为基准,其反式脂肪酸含量分别为：0．12％-0．25％、3．63％-6．58％。表明天然食用植物油中反式脂肪酸含量较低,但油脂在高温加工过程中会产生反式脂肪酸。     

Seasonal variation in the fatty acid composition of milk available at retail in the United Kingdom and implications for dietary intake

Milk and dairy products are major sources of fat in the human diet, but there are few detailed reports on the fatty acid composition of retail milk, trans fatty acids in particular, and how these change throughout the year. Semi-skimmed milk was collected monthly for one year from five supermarkets and analysed for fatty acid composition. Relative to winter, milk sold in the summer contained lower total saturated fatty acid (SFA; 67 vs 72 g/100 g fatty acids) and higher cis-monounsaturated fatty acid (MUFA; 23 vs 21 g/100 g fatty acids) and total trans fatty acid (6.5 vs 4.5 g/100 g fatty acids) concentrations. Concentrations of most trans-18:1 and -18:2 isomers also exhibited seasonal variation. Results were applied to national dietary intakes, and indicated that monthly variation in the fatty acid composition of milk available at retail has limited influence on total dietary fatty acid consumption by UK adults.     

Pd/C催化下碱木质素的高压加氢反应

为了提高碱木质素的反应活性,探讨了高压条件下,以Pd/C为催化剂,氢气对碱木质素的加氢反应。研究结果表明:在催化剂的负载量3%、用量10%,温度100℃,时间4 h,氢气压力3 MPa的条件下,反应后碱木质素的总羟基、醇羟基和酚羟基含量分别为15.69%、11.45%、4.24%,较反应前分别提高了158.1%、310.4%、28.9%。1H-NMR分析显示,代表羰基和羧基的质子吸收减少,而代表酚羟基和醇羟基的质子吸收增加。GPC分析表明,碱木质素结构单元间的缩合减少,质均分子质量和数均分子质量在反应后都有所下降,碱木质素的多分散性增大。元素分析显示,C和H的含量在反应后都有所增加,而O含量降低,表明碱木质素发生了还原反应。     

Pd/C催化下碱木质素与环己烯的还原反应

以钯/炭(Pd/C)为催化剂,以环己烯为氢给予体与麦秆碱木质素进行还原反应,分析了不同因素对反应过程的影响,通过正交实验优化了反应参数,用化学法对反应前后碱木质素官能团进行了定量测定,实验结果表明,最佳的Pd/C催化、环己烯还原法活化碱木质素的反应条件为:pH值10,催化剂质量分数7%,反应时间1.5h,碱木质素与环己烯质量比1:4.1,反应后碱木质素的总羟基含量为13.45%,增加了104.72%;羧基含量为1.60%,降低了39.39%;羰基2.96%,降低了50.99%.凝胶渗透色谱(GPC)分析表明,对于反应前后的碱木质素,其相对分子质量主要在1000～10000之间,所占比例分别为63.23%、84.66%,经Pd/C催化还原后碱木质素的多分散系数变小.     

食用油加氢过程催化剂对反式脂肪酸影响的研究进展

油脂氢化是油脂工业重要的反应过程,在此过程中油脂的结构和组成发生改变,在部分氢化过程中不可避免地产生反式脂肪酸.鉴于反式脂肪酸对人体健康有害,目前关于催化剂的研究大多集中在如何控制反式脂肪酸的生成量方面.就各种催化剂对食用油氢化反应的异构化影响进行讨论,重点介绍食品工业中使用的镍及其他诸如铜、金和铂族金属等非均相催化剂对反式脂肪酸生成量的影响,对非均相催化剂及与催化剂相关的载体、处理方法等诸种因素对顺式选择性的影响进行了简单阐述.     

钯/炭催化剂对碱木质素还原反应的催化作用

采用甲醛还原法制备钯/炭(Pd/C)催化剂,考察了以Pd/C为催化剂,以环己烯为氢给予体的催化体系对麦秆碱木质素还原反应的催化作用,用化学法对反应前后碱木质素官能团进行了定量测定,用FTIR、UV和1H NMR光谱对木质素化学结构进行了分析.结果表明,Pd/C催化剂对碱木质素还原反应具有较高的催化活性,碱木质素总羟基含量增加了46.95%,酚羟基含量增加了33.74%,醇羟基含量增加了63.93%;甲氧基含量降低了17.73%,羧基含量降低了53.41%,总酸性基变化不大,木质素的苯环结构稳定,活性官能团增加,反应活性提高,PdC催化剂对木质素还原活化反应具有良好的催化作用.     

Pd／C催化下空气氧化新戊二醇反应的研究

将Cannizzaro反应所生成的新戊二醇在Pd/C催化下 用生氧化生成羟基特戊酸。对催化活性及反应条件进行了研究，并对产物进行了表征。     

Deodorisation process variables for croaker (M. furnieri) oil

Fish oil is the major food source of the long-chain omega-3 polyunsaturated fatty acids. Deodorisation represents a critical step of the refining process since it involves high temperature that could induce degradation reactions which affect oil integrity and quality. The present study evaluated the effect of the deodorisation variables (temperature, time and steam) on the croaker (Micropogonias furnieri) oil refining process. The evaluated parameters were Lovibond color (LC), free fatty acids (FFA), peroxide (PV), Iodine (IV) and Saponification (SV) values. The best deodorisation conditions were at 220 °C, 60 min and 5% of steam (based in oil mass), resulting in oil with LC of 0.4 red and 30 yellow, FFA of 0.09%, PV of 0.53 meq/kg. IV and SV were not significantly affected. The obtained fish oil presented high quality and oxidative stability, as well as EPA and DHA contents of approximately 12% of total fatty acids.     

食用油脂多元加氢催化剂的制备研究

用浸渍法制备负载在凹凸棒土载体上的多元(Fe、Cu、La)镍基催化剂用于食用油脂加氢,通过碘值的测定评价催化剂的活性,并讨论了不同因素对催化剂活性的影响。     

Cytooxidative effects of α‐tocopherol and ascorbyl palmitate on thermal oxidation of canola oil

Canola oil, with and without added α‐tocopherol and ascorbyl palmitate, was used to deep‐fat frying potatoes once per day for 10 day or once per week for 10 weeks. Changes in chemical and physical properties were monitored. Refractive index, free fatty acids and absorbance at 232 and 270 nm increased with frying time. Smoke point, ‘L’ color index, iodine value and the C_18 : 2/C_16 : 0 ratio in the oil decreased with the frying time. According to smoke point, which shows the time of the oil should be discarded, canola oil without antioxidant (control) can be used safely 8 times daily or 7 times weekly. For canola oil with antioxidant (oil + α‐tocopherol + ascorbyl palmitate( the smoke point did not decrease below 170°C in both daily and weekly fryings. This showed that canola oil with antioxidant could be used safely at least 10 times for both frying intervals. In both daily and weekly fryings, the addition of 200 ppm α‐tocopherol and 200 ppm ascorbyl palmitate increased the oxidative stability of canola oil.     

制备条件对Ni／Al2O3催化剂催化性能的影响

用混合杂多酸处理工业ｒ－Ａｌ２Ｏ３载体，制备了一种低镍含量Ｎｉ／Ａｌ２Ｏ３催化剂。经微反等证实；此催化剂在苯加氢制环己烷反应中所表现出的催化性能均与催化剂的制备条件密切相关。     

Cu-salen配合物催化大豆油环氧化合成环保塑化剂

以3,5-二叔丁基水杨醛和乙二胺(摩尔比2∶1)为原料合成了N,N’-二3,5 -二叔丁基水杨醛基乙二胺(salen配体),salen配体与Cu( OAC)2·H20的乙醇溶液混合回流得到Cu - salen配合物.对重结晶提纯后的salen配体及配合物进行了红外、紫外、核磁等表征.Cu - salen配合物作为大豆油环氧化反应催化剂,以叔丁基过氧化氢(TBHP)为氧源,最佳反应条件为:60℃下反应8h,催化剂用量为大豆油质量的2％,得到最佳环氧化效果,其环氧产物转化率为52.5％,选择性为59.6％.超声波辅助下,环氧值由2.2％提高到4.0％,环氧值提高了45％;转化率提高至71.4％,选择性提高到63.5％;反应时间由8h缩短至0.5h,催化剂用量减少为大豆油质量的0.5％.     

Monounsaturated fatty acid oligomerization is responsible for the agglutination activity of heated virgin olive oil

The present study focuses on the isolation, purification and characterization of a molecule formed when virgin olive oil is heated at 130 °C for 24 h in air, that is found to be a strong agglutinin. The hemagglutinating activity of the novel molecule isolated from the heated olive oil was evaluated against human red blood cells (RBCs). Thin layer chromatography (TLC) of the oil mixture showed appearance of high molecular weight molecules, dimers and polymers. ¹³C nuclear magnetic resonance (NMR) and mass chromatography–mass spectroscopy (GC–MS) were used for structure elucidation. A linear oligomerization of monounsaturated fatty acids is involved. Light microscopy and electron microscopy were used to characterize and visualize the agglutination process. Agglutination without lysis or fusion was observed. The unheated olive oil and the isolated compound were also tested in-vitro against normal and malignant colon and breast cells. The results showed the highest reduction of tumor cells with the isolated novel compound. We conclude that virgin olive oil when heated in air produces oligomerization/polymerization of free unsaturated fatty acid possibly oleic acid (OA) that is a strong hemagglutinin against human RBCs with possible anti-cancer properties but with unknown nutritional effects on human health.