共查询到20条相似文献,搜索用时 31 毫秒
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采用两步酶法合成母乳脂替代品。以油茶籽油和棕榈酸为原料,在有机相体系中利用脂肪酶Novozym 435催化合成Sn-2位富含棕榈酸的甘油三酯,通过单因素试验和响应面设计,获得了最佳合成条件为反应溶剂正己烷、溶剂用量10 m L/g、底物(棕榈酸-油茶籽油)质量比1.1∶1、脂肪酶用量(以底物质量计)10.1%、反应时间16.5 h、反应温度50℃,Sn-2位棕榈酸含量达到66.08%;以第一步酸解反应得到的甘油三酯和鱼油为底物,经Sn-1,3专一性脂肪酶Lipozyme TL IM催化酯交换制备母乳脂替代品。制品检测结果表明,其不仅棕榈酸的含量和分布与母乳脂相似,而且具有较高含量的二十碳五烯酸、二十二碳六烯酸等多不饱和脂肪酸,亦可作为婴儿配方奶粉的脂肪来源。 相似文献
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目的:探讨无溶剂体系酶法合成己酸乙酯的最佳工艺条件。方法:在单因素试验的基础上,以脂肪酶添加量、底物(己酸/乙醇)物质的量比、反应时间为影响因素,应用二次回归中心组合试验法进行三因素五水平试验,以己酸乙酯产率为评价指标,进行响应面分析。结果:无溶剂体系酶法合成己酸乙酯的最佳工艺条件为脂肪酶添加量0.5%、酸醇物质的量比1:1.3、反应时间12.2h、反应温度30℃,转速150r/min。在此条件下,己酸乙酯产率实际值为81.6%,与预测值相近。结论:采用中心组合试验设计--响应面法对无溶剂体系酶法合成己酸乙酯工艺条件进行优化合理可行。 相似文献
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为提高废弃含杂纤维的回收率,以废弃的聚对苯二甲酸乙二醇酯基含杂纤维(PET/SrAl2O4:Eu2+,Dy3+)为研究对象,采用乙二醇醇解联合热乙醇的方法,探究含杂纤维的醇解性能并回收发光材料SrAl2O4:Eu2+,Dy3+及PET醇解产物对苯二甲酸双羟乙酯。通过改变乙二醇用量、反应温度及反应时间探讨乙二醇醇解条件对产物性能的影响,借助扫描电子显微镜、X射线衍射仪、差示扫描量热仪、分光光度测色仪、长余辉亮度仪等对醇解产物的微观形貌、物相结构、热稳定性能、余辉性能等进行测试与表征。结果表明:乙二醇用量、反应温度、反应时间和催化剂用量均不会改变发光材料SrAl2O4:Eu2+,Dy3+的物相结构;当反应温度为190℃,反应时间为180 min时,含杂纤维的醇解率达到100%,此时SrAl2O4 相似文献
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本文论述以阴离子层柱材料作催化剂,进行醇解反应制备皮革加脂剂中间体。以植物油为原料进行酯交换反应,制得脂酸甲酯,甘油单双酯,或甲基丙烯酸甲酯醇解制甲基丙烯酸高级醇酯。可进一步合成LWF结合型加脂剂,改性菜油加脂剂,磷酸酯加脂剂,丙烯酸加脂复鞣剂。 相似文献
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探讨了在醇相体系中甲醇钠催化制备甘油磷脂酰胆碱(L-alpha glycerylphosphorylcholine)的可行性,建立了磷脂酰胆碱(phosphatidylcholine)和L-α-GPC的HPLC-ELSD检测方法,研究了温度、料液比、甲醇钠添加量、反应时间对PC转化率和GPC得率的影响。利用Design Expert软件对工艺参数进行优化,得最佳条件:温度35℃、料液比3/20(g/mL)、甲醇钠添加量2 mL、反应时间1.5 h,GPC得率为88.2%。极差分析结果,反应条件对GPC得率影响的顺序为:甲醇钠添加量>温度>反应时间>料液比。大豆粉末磷脂的醇解反应液经过硅胶柱色谱纯化,最终可以得到纯度为99.8%的L-α-GPC,回收率78.4%,这为工业级规模制备高纯L-α-GPC提供了一种好的思路和方法。 相似文献
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反应介质对脂肪酶活力及催化猪油水解和甲醇解的影响 总被引:1,自引:0,他引:1
研究了反应介质对脂肪酶活力及其催化猪油水解和甲醇解的影响,反应介质包括有机溶剂、缓冲液和甘油.实验结果表明,在脂肪酶催化猪油水解和甲醇解体系中,反应介质对脂肪酶活力和猪油转化率影响很大,添加20%(v/v)的正己烷比不添加正己烷的转化率提高8.8%,在40%的正己烷体系中添加20%(v/v)50mmol/L、pH 6.8的磷酸缓冲液比添加等量水的转化率提高29.2%,在40%的正己烷体系和20%的磷酸缓冲液体系中添加1.83%(v/v)的甘油比不添加甘油的转化率提高17.2%. 相似文献
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针对活性染料在纤维上染色的动力学性能,研究不同条件下一氯均三嗪型活性染料活性嫩黄K-6G(C.I.Reactive Yellow 2)在甲醇碱性水溶液中的醇解和水解反应动力学,并确定了pH值为10时,不同温度下该染料的醇解与水解反应速率常数。研究表明,在80℃,pH值为9~12之间,醇解效率随时间延长逐渐变少,且pH值越高,醇解效率减少的越快, pH值的升高不利于醇解反应进行,即染料的醇解反应优先性下降;在50~70℃,甲醇化反应占相对优势,其速率为水解速率的2~3倍;80~95℃,甲醇化反应速率常数和水解速率常数基本相等。同时实验中还发现染料的醇解和水解反应都是准一级反应。 相似文献
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脂肪酶在食用油脂工业上的应用 总被引:5,自引:1,他引:5
脂肪酶按其对底物的特异性不同可分为非特异性酶、1,3—定向酶和脂肪酸特异性酶,在食用油脂工业上具有较大应用价值的是1,3—定向脂肪酶。介绍了脂肪酶(主要是1,3—定向脂肪酶)在油脂水解、酯交换和生物精炼三个方面的应用原理、特点及实例,从而展示出了脂肪酶催化技术在食用油脂工业上应用的前景 相似文献
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Kanika Mitra Seong-Ai Kim Jeung-Hee Lee Sang-Won Choi Ki-Teak Lee 《Food science and biotechnology》2010,19(1):57-62
The purpose of this study was to enrich α-linolenic acid (ALA) on the triacylglycerol (TAG) molecules of the selected vegetable oils (soybean and corn oil) in order to synthesized structural lipid (SL) with low ω6 to ω3 ratio. SLs were synthesized by lipase-catalyzed interesterification of soybean (SO) and corn oil (CO) with perilla oil (PO). Lipozyme RM IM from Rhizomucor miehei (5% by weight of total substrate) was used for the reaction. The reaction was performed during 24 hr at 55°C in the stirred-batch type reactor with solvent free system. After 24 hr reaction the ratio of ω6 to ω3 in SL products dramatically decreased comparing to that of substrates (SO and CO) before the reaction. At sn-2 position, the contents of ALA were 25.99% in soybean-SL and 23.25% in corn-SL, respectively. According to the equivalent carbon number (ECN) of TAG profile, newly produced SLs were separated by reverse-phase high performance liquid chromatography (HPLC). These results indicated that lipase-catalyzed interesterification is effective to produce SL with low ω6 to ω3 ratio which might be used as health beneficial oil. 相似文献
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Azócar L Ciudad G Heipieper HJ Muñoz R Navia R 《Journal of Bioscience and Bioengineering》2011,112(6):583-589
One major problem in the lipase-catalyzed production of biodiesel or fatty acid methyl esters (FAME) is the high acidity of the product, mainly caused by water presence, which produces parallel hydrolysis and esterification reactions instead of transesterification to FAME. Therefore, the use of reaction medium in absence of water (anhydrous medium) was investigated in a lipase-catalyzed process to improve FAME yield and final product quality. FAME production catalyzed by Novozym 435 was carried out using waste frying oil (WFO) as raw material, methanol as acyl acceptor, and 3 Å molecular sieves to extract the water. The anhydrous conditions allowed the esterification of free fatty acids (FFA) from feedstock at the initial reaction time. However, after the initial esterification process, water absence avoided the consecutives reactions of hydrolysis and esterification, producing FAME mainly by transesterification. Using this anhydrous medium, a decreasing in both the acid value and the diglycerides content in the product were observed, simultaneously improving FAME yield. Enzyme reuse in the anhydrous medium was also studied. The use of the moderate polar solvent tert-butanol as a co-solvent led to a stable catalysis using Novozym 435 even after 17 successive cycles of FAME production under anhydrous conditions. These results indicate that a lipase-catalyzed process in an anhydrous medium coupled with enzyme reuse would be suitable for biodiesel production, promoting the use of oils of different origin as raw materials. 相似文献
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Pinolenic acid (PLA) concentrate in fatty acid ethyl ester (FAEE) was efficiently produced from pine nut oil via lipase-catalyzed ethanolysis using a recirculating packed bed reactor (RPBR). The effects of reaction temperature, molar ratio, and residence time on the concentration of PLA were explored. Novozym 435 lipase from Candida antarctica showed less selectivity toward PLA esterified at the sn-3 position when temperature was increased from 45 to 55 °C. For the trials of molar ratio between 1: 50 and 1: 100 (pine nut oil to ethanol), there were no significant differences in the yield of PLA. Residence time of substrate in a RPBR affected significantly the PLA content as well as the yield of PLA. Optimal temperature, molar ratio (pine nut oil to ethanol), and residence time for production of PLA concentrate via lipase-catalyzed ethanolysis in a RPBR were 45 °C, 1: 50, and 3 min, respectively. Under these conditions, the maximal PLA content (36.1 mol%) in the concentrate was obtained during the initial 10 min of reaction. 相似文献
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超临界CO2中脂肪酶催化甘油解制备单甘酯的研究进展 总被引:1,自引:0,他引:1
论述了超临界CO2条件下脂肪酶催化甘油解制备单甘酯的研究进展,并从反应温度、压力、含水量、底物比例、脂肪酶活性等方面对反应的影响进行了探讨.此法具有反应温度低,产品色泽好,无溶剂残留,操作步骤大大简化等优点,有望成为食品用单甘酯最有潜力的生产方法. 相似文献
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以回收的变质油脂先制成精炼油脂,然后进行醇解反应制备脂肪酸甲酯,是一种很好的加脂剂原料,可以合成LWF结合型加脂剂。或进行醇解制备甘油单、双酯,然后制得硫酸化油加脂剂。 相似文献