异丙苯氧化的研究进展

异丙苯氧化反应在石油化学工业中有着重要的地位,主要对国内外异丙苯氧化所用的催化剂体系及反应机理进行了总结和综合性评述,并展望了该领域今后的研究方向。     

利用核磁共振研究脂肪氧合酶酶促氧化蛋黄磷脂

利用31P核磁共振比较酶促氧化前后蛋黄磷脂的组成,通过1H核磁共振监测并比较空白组（未氧化）与脂肪氧合酶酶促氧化及95 ℃水浴加热氧化过程中脂肪酰基的相对物质的量、一级和二级氧化化合物含量的变化。结果表明：磷脂酰胆碱和磷脂酰乙醇胺是蛋黄磷脂的主要成分;蛋黄磷脂氧化后,磷脂酰胆碱和磷脂酰乙醇胺含量均下降,而溶血性磷脂含量增加;所有被氧化的蛋黄磷脂样品中总不饱和脂肪酸相对物质的量均下降,而饱和脂肪酸相对物质的量均上升;其中在pH 6酶促条件下,亚油酸降解速率最快。脂肪氧合酶在pH 6条件下催化氧化蛋黄磷脂生成更多的氢过氧化物,加热后主要生成(Z,E)-2,4-二烯醛;而在pH 9条件下蛋黄磷脂生成氢过氧化物后快速降解,在加热后生成较多正构烷醛。因此,可以利用脂肪氧合酶在pH 6条件下催化氧化蛋黄磷脂生成更多的2,4-二烯醛类风味化合物。     

Effect of γ-Oryzanol on the Flavor and Oxidative Stability of Refrigerated Cooked Beef

ABSTRACT: γ-Oryzanol and α-tocopherol were added to beef patties as natural antioxidants. Beef patties containing 100 ppm γ-oryzanol had higher oxidative stability ( P <0.05) during storage at 4 °C than did beef patties with other antioxidants and without antioxidant. Thiobarbituric acid-reactive substances (TBARS) values, warmed over flavor (WOF) scores, C-7 oxidized cholesterol derivatives (OCDs), and concentrations of both hydroperoxide and hexanal in the cooked beef containing γ-oryzanol were significantly lower than those of other treatments ( P < 0.05). All variables had similar trends during the refrigerated storage. Significant correlations were found between TBARS and C-7 OCDs, TBARS and WOF, hydroperoxide and hexanal, and hexanal and WOF ( P < 0.05).     

以酶催化氧化油脂的方法制备香味料的研究进展

脂肪氧合酶催化油脂中的不饱和脂肪酸生成氢过氧化物,氢过氧化物再在裂解酶的作用下,生成具有青草香、青叶香香气特征的挥发性醛类物质。主要论述了不饱和脂肪酸酶催化氧化的基本途径,脂肪氧合酶的制备及氢过氧化物的生成,裂解酶的制备及氢过氧化物的裂解过程。并介绍了酶催化氧化油脂生成香味料的现状,展望了其发展前景。     

The influence of the solvent on the epoxidation of cis,trans,trans-1,5,9-cyclododecatriene to trans-1,2-epoxy-cis,trans-5,9-cyclododecadiene by catalytic system tert-butyl hydroperoxide/Mo(CO)6

The epoxidation of cis,trans,trans-1,5,9-cyclododecatriene to trans-1,2-epoxy- cis,trans-5,9-cyclododecadiene with the use of commercial solution of tert-butyl hydroperoxide in various organic solvents:tert-butyl peroxide, isooctane, decane, and nonane was investigated. The process was investigated in different experimental conditions. The best results were achieved with the application of tert-butyl hydroperoxide in isooctane. A significant influence of the nature of the solvent on the results of trans-1,2-epoxy-cis,trans-5,9-cyclododecadiene synthesis was found.     

氯代环己烷的合成

介绍了氯代环己烷的合成工艺及其应用。     

α-甲基苯乙烯合成过氧化二异丙苯工艺研究

采用 α-甲基苯乙烯为起始原料合成过氧化二异丙苯 ,对反应工艺和后处理条件进行了实验研究 ,改进了反应过程投料方式。所得颗粒状结晶 DCP熔点 38.5～38.9°C。     

Pronounced Catalytic Effect of Micellar Solution of Sodium Dodecyl Sulfate (SDS) for Regioselective Iodination of Aromatic Compounds with a Sodium Iodide/Cerium(IV) Trihydroxide Hydroperoxide System

Micellar solutions of sodium dodecyl sulfate (SDS) catalyze the regioselective iodination of a wide range of aromatic compounds with sodium iodide in the presence of the easily prepared, water‐resistant and recyclable cerium(IV) trihydroxide hydroperoxide, Ce(OH)₃O₂H, at room temperature. By this protocol, structurally diverse aromatic compounds including benzene and naphthalene were iodinated in good to excellent yields.     

Ga2O3/凹凸棒石复合催化剂的制备和肉桂酸环己酯的催化合成

采用浸渍法由凹凸棒石负载氧化镓(Ga2O3)制备了Ga2O3/凹凸棒石复合催化剂。用IR、XRD、BET、TEM等对催化剂结构进行了表征,并通过肉桂酸环己酯的合成,对催化剂制备条件、催化活性和反应动力学特性进行了考察。结果表明,催化剂的最佳制备条件是Ga2O3负载量为催化剂总质量的10 %,焙烧温度450 ℃;在肉桂酸环己酯合成过程中,当n(肉桂酸):n(环己醇)=1:4.5(其中肉桂酸0.02 mol),催化剂用量0.5 g,反应温度130 ℃,反应时间70 min时,产品平均酯化率为95.0 %,催化剂经5次重复使用,酯化率仍达81.5 %;反应为准二级反应,表观活化能为90.78 kJ/mol,130 ℃时反应速率常数为1.03×10-2 L/(mol•min)。     

二氧化双环戊二烯反应液的高效液相色谱分析

采用高效液相色谱建立了快速分析二氧化双环戊二烯反应液中溶剂异丙苯、氧化剂过氧化氢异丙苯和反应副产物2-苯基异丙醇的新方法。以Agilent Eclipse XDB C18型色谱柱为分离柱,乙腈/0.1%(φ)磷酸为流动相,梯度淋洗,流量1.0 mL/min。实验结果表明,目标组分分离效果良好,且各目标化合物在各自配制的浓度范围内线性关系良好,回归系数均达到0.999 9,各目标组分的最低检出限为0.15～0.25 mg/L,加标回收率为101.9%～111.6%,相对标准偏差均不高于2.37%,定量结果准确可靠,数据精密度良好,为二氧化双环戊二烯生产企业提供了一种简便、快速、准确的分析方法。