共查询到18条相似文献,搜索用时 78 毫秒
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在水溶液中,采用Tween40、蔗糖酯S970、Span60三种表面活性剂修饰猪胰脂酶(porcine pancreas lipase,PPLipase);再以修饰的猪胰脂酶(Tween40-PPLipase、S970-PPLipase、Span60-PPLipase)为催化剂,在无溶剂体系中催化茶油与亚油酸酯交换反应。结果表明,在酶促反应达到平衡前,随着加酶量的增加酯交换量也随之增加;在相同的加酶量下,Tween40-PPLipase、S970-PPLipase和Span60-PPLipase催化酯交换的速率均高于PPLipase催化酯交换的速率;加酶量5%时,2h时PPLipase催化反应的酯交换量为16.1%,Tween40-PPLipase、Span60-PPLipase和S970-PPLipase催化反应的酯交换量分别为20.4%、21.1%和22.4%。达到平衡时,Tween40-PPLipase、Span60-PPLipase、S970-PPLipase和PPLipase催化反应的酯交换量基本相同,均为25%左右。 相似文献
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无溶剂系统酶促POMF酯交换反应生产CBE的正交实验研究 总被引:3,自引:0,他引:3
本文运用正交实验研究了在无溶剂系统中,利用1,3位置特异性脂肪酶催化POMF与硬脂酸甲酯进行酯交换反应制取类可可脂。结果表明:应以Lipozyme IM做为催化剂,反应温度为55℃,振荡速度为150r/min,酶/底物配比为300U/10g,硬脂酸甲酯/POMF配比为1,且其产品经过差示扫描量热法(DSC)分析,热性能符合类可可脂质量的要求。 相似文献
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无溶剂状态下乌桕皮油酶促酯交换改性制取类可可脂的研究 总被引:5,自引:3,他引:5
研究了在无溶剂状态下,1,3专一性脂肪酶催化乌桕皮油酯交换反应制取类可可脂的工艺,确定了酯交换反应的最佳工艺条件,通过减压蒸馏,乙醇结晶分提分离纯化了酯交换后的油脂,并应用高压液相色谱,分析了类可可脂产品的甘油三脂结构,应用差示扫描量热法(DSC)分析了产品的性能。 相似文献
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固定化脂肪酶催化酯交换合成生物柴油研究 总被引:2,自引:0,他引:2
以苯乙烯为单体,二乙烯苯为交联剂,过氧化苯甲酞为引发剂,明胶为分散剂,采用悬浮聚合法制备St-DVB-CBA三元共聚高分子微球,将其作为固定化脂肪酶载体,通过共价结合法进行脂肪酶固定化,探讨固定化脂肪酶催化大豆油酯交换反应活性。实验结果表明:固定化脂肪酶在醇油摩尔比为3∶1,分三次加入;固定化酶加入量15wt.%(油重);反应时间24 h;反应温度40℃;正己烷加入量15wt.%(油重);水分含量4wt.%(油重);转化率最高,可达90.08%;固定化脂肪酶重复使用时显示出较好稳定性和催化活性。 相似文献
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无溶剂体系中复合酶催化大豆油水解的研究 总被引:1,自引:0,他引:1
研究了无溶剂体系中复合酶催化大豆油水解反应.对Sigma L-3126、PPL、C. lipolytica(CLL)、Novo435和Amano-G 5种不同来源的脂肪酶进行筛选和复合使用,得到了水解效果较好的CLL和Amano-G组合.超声波对复合酶反应有一定的促进作用,在反应开始阶段其作用较为明显;较好的反应条件为:CLL和Amano-G的加入量分别为1%和0.1%,在CLL反应1 h后加入Amano-G,反应温度45℃,去离子水直接加入反应体系作为水相,水油质量比1∶1.在此条件下反应24 h水解率由常规振荡水浴的45.7%提高到94.2%. 相似文献
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以玉米淀粉和油酸为原料,研究了无溶剂体系下油酸淀粉酯的酶催化合成。主要考察了酶与淀粉的质量比、反应温度、底物比、时间等参数对油酸淀粉酯取代度的影响。采用气相色谱法进行取代度的测定,并以取代度为考察指标,确定了最佳的工艺条件。在单因素试验的基础上进行正交试验,结果表明,最佳工艺条件为:酶的添加量为6%、温度70℃、底物质量比1∶7,在上述条件下反应12 h,取代度可达0.201。同时,使用紫外吸收光谱和FT-IR谱图对产物结构进行表征。 相似文献
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Lipozyme在桕脂改性中的应用 总被引:1,自引:1,他引:1
本文通过对Lipozyme酶促酯交换的研究,证实Lipozyme非常适于在油脂改性工程中作为酯交换催化剂促进反应。通过实验研究指出,借助Lipozyme的酶促酯交换桕脂是一种极好的类可可脂生产原料。 相似文献
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Chae MH Park HK Kwon KI Kim JW Hong SI Kim Y Kim BH Kim IH 《Journal of food science》2011,76(4):C555-C559
Lipase-catalyzed interesterification of high oleic sunflower oil and fully hydrogenated soybean oil (70 : 30, wt/ wt) was carried out in a packed bed reactor using an immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) and the effect of a stepwise temperature protocol involving the 2 different temperatures, 60 and 70 °C, was investigated. The melting point of a fat that was incubated at 70 °C for 9 min was 57 °C, which suggested that it should be to employ a lower reaction temperature of 60 °C, after the first 9 min of the reaction. There were no significant differences (P < 0.05) in the conversion degree, triacylglycerol profile, and solid fat content between a constant temperature protocol (70 °C) and a stepwise temperature protocol (a combination of 70 and 60 °C). After 50 cycles, the overall residual activities of enzymes employed in stepwise temperature protocol were significantly (P < 0.05) higher than those of enzymes employed in constant temperature protocol. 相似文献
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Ariela V. Paula Gisele F. M. Nunes Júlio C. Santos Heizir F. de Castro 《International Journal of Food Science & Technology》2011,46(10):2124-2130
The potential of the lipase from Rhizopus oryzae immobilised on SiO2‐PVA to catalyse the interesterification of the milkfat with soybean oil in a packed bed reactor running on continuous mode was evaluated. The reactor operated continuously for 35 days at 45 °C, and during 12 days, no significant decrease in the initial lipase activity was verified. Interesterification yields were in the range from 35 to 38%wt, which gave an interesterified product having 59% lower consistency in relation to non‐interesterified blend. Results showed the potential of the lipase from Rhizopus oryzae to mediate the interesterification of milkfat with soybean oil in packed bed reactor, attaining a more spreadable product under a cool temperature. The biocatalyst operational stability was assessed and an inactivation profile was found to follow the Arrhenius model, revealing values of 34 days and 0.034 day?1, for half‐life and a deactivation coefficient, respectively. 相似文献
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