松香催化酯化反应研究进展

综述了30年来松香催化酯化反应的研究进展,重点考察了反应使用的催化剂、反应条件以及产品性能,对进一步研究松香酯化改性具有指导意义,并有利于我国松香资源的充分利用。     

菜籽油甲酯化及其动力学研究

本文报道菜籽油甲酯化反应的适宜条件为菜籽油/甲醇（摩尔比）为1/6,0.5％NaOCH_3作催化剂,反应温度40～60℃之间,反应时间在1小时内。用NMR—24B型核磁共振仪作为分析检测手段。动力学研究表明,该反应分为两个阶段:开始的四级对峙反应,速度常数的数量级为10~（-4）、表观活化能65.2KJ·mol~（-1）;后面的二级对峙反应,速度常数的数量级为10~（-2）。本研究为菜籽油甲酯化在工业上生产加脂剂提供了理论上的参考数据。     

Dietary astaxanthin levels affect colour,growth, carotenoid digestibility and the accumulation of specific carotenoid esters in the Giant Tiger Shrimp,Penaeus monodon

The carotenoid astaxanthin (Axn) plays a vital role in shrimp pigmentation, with direct influence on product quality, and forms a significant cost component of shrimp aquaculture feeds. However, the effects of dietary Axn on other measures of shrimp physiological performance are varied, and the efficiency of carotenoid uptake from the diet and deposition in shrimp tissues is poorly defined. This study fed juvenile shrimp (Penaeus monodon) diets that contained 0, 25, 50 or 100 mg kg^?1 Axn for 6 weeks. Shrimp fed carotenoid‐free diets had significantly reduced colour and growth than those fed carotenoids, but survival was unaffected. Carotenoid digestibility improved as dietary carotenoid levels increased, and was 98.5% in shrimp fed 100 mg kg^?1 Axn. After 6 weeks, whole body carotenoid levels were significantly depleted in 0 or 25 mg kg^?1 fed shrimp, compared with those fed 50 or 100 mg kg^?1 or compared with initial shrimp. This study also showed that Axn monoesters were enriched with saturated fatty acids, whereas Axn diesters were enriched with monounsaturated and polyunsaturated fatty acids. Combined, these studies demonstrate that a total dietary carotenoid intake of between 25 and 50 mg kg^?1 Axn is required for normal shrimp growth and health in P. monodon. Evidence suggests that there is a functional role for the accumulation of carotenoids and the formation of specific Axn fatty acid esters, and these may be linked to the metabolism, storage, mobilization or deposition of Axn within various tissues.     

烟草中非挥发性有机酸的甲酯化条件优化及定量分析

采用气相色谱-质谱法对15个不同产区的烟丝中苹果酸、富马酸、油酸等8种非挥发性有机酸进行定量分析并对甲酯化时间和甲酯化试剂的用量进行优化。试验表明,烟丝中非挥发性有机酸甲酯化的最佳条件为:酯化时间50 min,温度70℃,酯化试剂为V三氟化硼∶V甲醇=3∶7,在此条件下非挥发性有机酸的回收率为79.50%~101.35%,相对标准偏差为3.34%~7.32%。     

生物柴油的研发现状与展望

介绍了国内外生物柴油研发中的原料来源途径、转酯化反应主要技术问题和产业化现状.提出了要使生物柴油生产达到能替代石化柴油的水平,必须重视原料来源的研究和原料基地的建设的观点.     

加速溶剂萃取-气相色谱法快速测定乌贼膏中的脂肪酸组成

研究了气相色谱法快速分析乌贼膏中脂肪酸组成的方法。通过试验比较了索式提取、超声提取和加速溶剂萃取3种方法的提取效率,同时对检测多种脂肪酸甲脂的气相色谱参数进行全面优化,建立了GC快速分析方法。结果表明,加速溶剂萃取法大大缩短了提取时间,提取出来的脂肪酸经三氟化硼-乙醚催化甲脂化,采用Agilent HP-88色谱柱分析,从乌贼膏中共检出23种脂肪酸,均达到基线分离。本方法快速、准确,可用于乌贼膏中脂肪酸组成的定性和定量分析。     

磷酸/离子液体复合体系催化合成乙酸松油酯的研究

将3种磷酸与离子液体组成的复合体系用于催化合成乙酸松油酯的反应,其中,H3PO4/[C4m im]BF4和H3PO4/[C8m im]BF4均显示出很高的催化活性;以H3PO4/[C4m im]BF4为代表,详细考察了反应的影响因素;得出最佳工艺条件:n(松油醇)∶n(乙酸酐)为1∶1.5,松油醇0.03 mol,磷酸0.03 g,反应温度40℃,反应时间10 h,离子液体[C4m im]BF45 g,此条件下所得粗产物中未反应松油醇质量分数仅为0.9%,松油醇的质量分数86.5%,松油烯11.0%。H3PO4/[C4m im]BF4复合体系重复使用7次后,适当补加H3PO4可使催化活性与新催化体系相当。     

Fatty acid digestibility in gilthead sea bream fed diets containing native,re‐esterified or acid vegetable oils

Re‐esterified vegetable oils are obtained from a chemical esterification reaction between vegetable acid oils and glycerol. Due to their properties, it is expected that they have a higher nutritive value than their corresponding acid oils and a better digestibility than their native counterparts. The aim of this study was to determine the effect of re‐esterified oils with a different monoacylglycerol (MAG) and diacylglycerol (DAG) content, produced from palm or rapeseed, on fatty acid digestibility in gilthead sea bream (Sparus aurata). Triplicate groups of fish were fed nine experimental diets containing different oils during 28 days. For each source, four different types of oil were used: native, re‐esterified low or high in MAG and DAG and acid. A commercial fish oil was used for the control diet. Diets containing re‐esterified oils had better apparent digestibility coefficients (ADC) of total fatty acids than acid oil diets. Re‐esterified oils do not negatively affect apparent digestibility coefficients of fatty acids when compared to their corresponding native oils and could be incorporated as a source of energy in diets for gilthead sea bream. An improvement in digestibility compared to the native oil diet was only obtained in palm re‐esterified oil high in MAG and DAG.     

响应面法优化酶促脂肪酸甲酯化工艺条件

为了获得菜籽油脂肪酸酶促甲酯化合成生物柴油的最佳反应条件,首先采用Plackett-Burman法对影响酯化率的5个因素进行筛选,发现酶质量分数、反应温度、摇床转速和反应时间4个因素显著影响酯化率。基于该4因素的最陡爬坡试验、Box-Behnken设计及响应面分析结果表明：反应温度是影响酯化率的最显著因子,反应时间的作用效果相对较弱,反应温度和摇床转速具有明显的互作效应。在优化条件下,醇/脂肪酸摩尔比1.25∶1、酶质量分数11.5 g/kg脂肪酸、反应温度42.2℃、摇床转速199 r/min,反应6 h后,酯化率可达95.67%,与响应面拟和方程的预测值（96.52%）吻合良好。     

杨木塑合木制备初探——Ⅱ．杨木酯化塑合木的制备

初步研究了酯化与塑合木相结合的杨木改性处理工艺条件。用甲基丙烯酸酯化后,再用甲基丙烯酸甲酯－甲基丙烯酸浸渍共聚,毛白杨（Populus tomentosa)抗缩率可达68．37％,文县杨（P.wenxianese)达70．15％。