MLM型结构脂的酶法合成及其理化性质分析

以醇解反应制得单甘酯和辛酸为底物,1,3-特异性固定化脂肪酶为催化用酶,在单因素试验的基础上,通过正交试验获得酯化反应制备MLM型结构脂质的最适条件：Lipozyme RM IM酶加入量9%(以底物质量计)、反应时间14h、反应温度40℃、单甘酯与辛酸(底物)物质的量比1:6;该条件下辛酸插入率达60.48%,其中92.84%的辛酸分布在甘油结构的1,3位上。经二级分子蒸馏纯化后得到的MLM型结构脂质,辛酸插入率达到73.34%;对其进行理化指标检测分析表明,该产品最低可达国家四级菜籽油的标准。     

响应面法优化填充床反应器固定化酶催化制备MLM型结构脂质

以菜籽油和辛酸为底物,研究固定化脂肪酶在填充床中酶催化制备MLM型结构脂质的条件,在单因素试验的基础上,通过中心组合试验,考察反应时间、底物(菜籽油和辛酸)物质的量比、反应温度、水分质量分数因素及其相互作用对MLM型结构脂质含量的影响,得到填充床固定化酶催化制备MLM型结构脂质的最佳工艺条件。结果表明最佳工艺条件为:保留时间为2 h,底物物质的量比为4.5,温度为60℃,水分质量分数为0.15%,在此工艺条件下制备的MLM型结构脂质的摩尔分数为46.12%。填充床固定化酶催化制备MLM型结构脂质的二次多项回归模型拟合度良好,可以用于实际生产预测。     

两步酶法合成MLM型结构脂质中醇解反应研究

为获得纯度较高的2-单甘酯来制备MLM型结构脂质,以菜籽油和无水乙醇为底物,用来自Thermomyceslanuginosa固定化脂肪酶TL IM作为催化酶来制备2-单甘酯。在单因素试验的基础上,采用正交试验设计,获得醇解反应的最佳工艺条件:菜籽油/无水乙醇(底物)物质的量比1:5,Lipozyme TL IM酶加入量为7%(以底物质量计)、反应温度35℃、反应时间18h,总单甘酯含量为38.82%。经三级分子蒸馏纯化后,总单甘酯的纯度可以达到90.76%。     

无溶剂体系中酶催化合成结构脂质条件初探

以菜籽油和辛酸为原料,在无溶剂体系中用脂肪酶催化酸解合成结构脂质。对6种不同来源的脂肪酶进行筛选,结果表明Lipozyme RMIM催化活性高、Sn-1,3位特异性强。以Lipozyme RMIM为催化用酶,考察了反应时间、反应温度、底物比(菜籽油与辛酸摩尔比)、加酶量、体系水分含量对酸解反应的影响。结果表明,在反应时间15 h,反应温度50℃,底物比1∶4,加酶量10%条件下,辛酸合成率达40%。     

酶催化大豆油酸解制备质构脂质反应条件的优化

探讨了正己烷体系中各因素对酶催化大豆油酸解制备质构脂质反应的影响,在单因素实验基础上,采用响应面设计实验,以辛酸插入率为考察指标,确定了最佳反应条件。结果表明,最优反应条件为:反应温度35.8℃,加酶量11.9%(底物的质量分数),底物摩尔比5.7∶1(辛酸/大豆油),加水量15.4%(酶的质量分数),反应时间20.4 h。在此条件下,实验测得辛酸插入率高达44.903 7%,与模型预测值45.689 8%非常吻合。     

酶催化桑蚕蛹油酯交换制备中长链脂肪酸甘油酯

以桑蚕蛹油为底物,通过酶法催化其与三辛酸甘油酯进行酯交换反应,制备富含α-亚麻酸的中长链脂肪酸甘油三酯(MLCTs)。通过单因素实验考察了酶种类、底物质量比、反应温度、加酶量以及反应时间对酯交换反应的影响,对酯交换条件进行了优化。结果表明,最佳反应条件为：采用Lipozyme TL IM脂肪酶,三辛酸甘油三酯与桑蚕蛹油质量比1∶ 4,加酶量为底物质量的8%,反应温度45 ℃,反应时间10 h。在最佳反应条件下,酯交换反应的转化率为98.42%,酯交换产物中中长链脂肪酸甘油三酯含量为98.73%,辛酸含量为20.00%,α-亚麻酸含量为30.09%。     

Lipozyme RM IM脂肪酶催化酸解制备MLM型结构脂质

采用脂肪酶Lipozyme RM IM催化辛酸、癸酸与大豆油进行酸解反应以制备MLM型结构脂质。通过单因素实验研究底物摩尔比、辛癸酸摩尔比、酶添加量、反应时间、反应温度和初始水分含量对酸解反应的影响。得到适合的反应条件为:底物摩尔比3∶1(总脂肪酸/大豆油),辛酸与癸酸摩尔比(辛酸/癸酸)2.5∶1,酶添加量7.5 wt%(基于底物总重),反应时间5 h,反应温度65℃,加水量1.0 wt%(基于底物总重),得到MLM结构脂脂肪酸组成中辛酸含量为20.0 wt%,癸酸含量为10.5 wt%,两者质量比为1.92。     

基于核桃油-辛酸酶法合成的 新型结构脂

本文研究了以核桃油、辛酸为实验原料,通过Box-Benhnken响应面优化核桃油-辛酸结构脂的制备工艺,以其辛酸插入率为评价标准从固定化脂肪酶Novozym 435、Lipozyme TL IM 和 Lipozyme RM IM 中筛选出辛酸插入率最高的酶,考察底物摩尔比、酶的添加量、反应时间及反应温度对核桃油-辛酸结构脂中辛酸插入率的影响,在单因素试验的基础上,利用四因素三水平响应面法确定核桃油-辛酸结构脂的制备工艺。结果表明固定化脂肪酶 Lipozyme TL IM 较适合制备核桃油-辛酸结构脂,其最佳酸解反应的条件为底物摩尔比(辛酸:核桃油)为3:1,酶添加量为10wt%,反应时间为12.6h,反应温度为44.8℃,在此条件下,辛酸插入率为32.37%。该条件适于制备的核桃油-辛酸结构脂,通过对核桃油-辛酸结构脂制备工艺的优化可为结构脂的开发与应用提供理论借鉴。     

酶法改良大豆油制备质构脂质的研究

研究了固定化脂肪酶催化大豆油与辛酸酸解制备质构脂质的工艺.脂肪酶筛选实验表明,在所选用的三种脂肪酶中,来自Rhizomucor miehei的固定化脂肪酶RM IM催化效果最好.以RM IM为催化剂,进一步考察了酶用量、底物摩尔比、水分添加量、反应温度、反应时间等因素对辛酸插入率的影响.结果表明:当大豆油500mg时,最佳的反应条件为:反应温度40℃,底物摩尔比6∶1(辛酸∶大豆油),固定化酶10%(底物重量百分比),水分添加量10%(酶的重量百分比),反应24h,辛酸的插入率为43%,质构脂质的脂肪酸分布最合理.     

酸性离子液体催化大豆油酸解反应

研究了酸性离子液体催化大豆油与辛酸、癸酸反应合成中长碳链结构脂的主要影响因素。对离子液体进行了筛选,考察了底物摩尔比(大豆油与辛酸癸酸混合物(摩尔比3∶1)摩尔比)、催化剂添加量、反应温度、反应时间对中碳链脂肪酸(MCFA)结合率的影响。以1-羧甲基-3-甲基咪唑硫酸氢盐为催化剂,利用单因素实验确定最佳反应条件为:底物摩尔比1∶8,催化剂添加量12%(以底物质量计),反应时间9 h,反应温度130℃。在最佳反应条件下,反应产物中MCFA的结合率为46.72%,辛酸、癸酸的结合率分别为30.04%、16.68%。通过考察辛酸、癸酸参与反应的难易程度可知,癸酸较辛酸更容易发生酸解反应。     

有机溶剂中脂肪酶催化辛酸辛酯的合成

以猪胰腺脂肪酶为催化剂合成辛酸辛酯。研究有机溶剂、反应温度、加水量、加酶量、反应时间、底物浓度及底物物质的量比7 个因素对酶促酯化反应的影响,优化得到最佳合成条件。结果表明：最佳反应温度45℃、正己烷有机溶剂、加水量29μL、酶质量浓度2.314g/L、反应时间24h、辛酸与辛醇物质的量比为1:1.2～1:1.5、辛酸浓度为0.23～0.33mol/L。在优化条件下,辛酸的转化率达到98.12% 以上,并通过IR、1H NMR、13CNMR 谱表征了产物结构。酶催化法能在温和的反应条件下合成高产率的酯。     

LIPASE-CATALYZED PRODUCTION OF STRUCTURED LIPIDS VIA ACIDOLYSIS OF FISH OIL WITH CAPRYLIC ACID

Structured lipids containing eicosapentaenoic and docosahexaenoic acids were manufactured in a batch reactor by lipase-catalyzed acidolysis of fish oil with caprylic acid. The following free lipases (Lipase AP, Aspergillus niger ; Lipase P, Pseudomonus sp. ; Lipase AY, Candida rugosa ; Lipase AK, Pseudomonas fluoresescens ; Lipase F, Rhizopus oryzae ; Lipase D, Rhizopus delemar ) were screened under selected reaction conditions. The conditions were enzyme load 5%, substrate mole ratio 1:6 (fish oil: caprylic acid), and reaction temperature of 50C. Lipase AK had the highest activity and was suitable for production of structured lipids from fish oil. The optimal mole substrate ratio of fish oil to caprylic acid for Lipase AK was 1:6 to 1:8. The time course of the reaction at different enzyme loads demonstrated that 40% incorporation of caprylic acid could be obtained for Lipase AK in 5 h with 10% enzyme load. Addition of water had little effect on the activity of the lipase. Lipase AK and Lipozyme IM were further compared under the same conditions, in which Lipase AK had a slightly higher incorporation of caprylic acid, similar acyl migration of caprylic acid from sn-1,3 positions to the sn-2 position, and a slightly lower selectivity towards docosahexaenoic acid.     

酶法催化酯交换反应制备脂肪酸甲酯工艺研究

利用凯泰中性脂肪酶催化菜籽油与甲醇酯交换制备脂肪酸甲酯,相比而言,采用经乳化后菜籽油作反应原料具有更高转化率;为提高转化率,采用响应面实验设计和分析方法对菜籽油酯交换反应条件进行优化,得到最佳工艺条件:反应温度47℃,反应时间34小时,醇油摩尔比为4.5∶1,脂肪酶用量420UI;在此工艺条件下,酯交换反应转化率达95.81%。采用GC–MS技术分析所得样品,结果表明,菜籽油脂肪酸甲酯主要组份为油酸甲酯。     

Enzymatic synthesis of structured lipids using a novel cold-active lipase from Pichia lynferdii NRRL Y-7723

Structured lipids (SL) were synthesized by the acidolysis of borage oil with caprylic acid using lipases. Six commercial lipases from different sources and a novel lipase from Pichia lynferdii NRRL Y-7723 were screened for their acidolysis activities and Lipozyme RM IM and NRRL Y-7723 lipase were selected to synthesize symmetrical SL since recently NRRL Y-7723 lipase was identified as a novel cold-active lipase. Both lipases showed 1,3-regiospecifity toward the glycerol backbone of borage oil. The effects of enzyme loading and temperature on caprylic acid incorporation into the borage oil were investigated. For Lipozyme RM IM and NRRL Y-7723 lipase, the incorporation of caprylic acid increased as enzyme loading increased up to 4% of total weight of the substrate, but significant increases were not observed when enzyme loading was further increased. The activity of NRRL Y-7723 lipase was higher than that of Lipozyme RM IM in the temperature range between 10 and 20 °C.     

Lipase-catalyzed acidolysis of olive oil and caprylic acid in a bench-scale packed bed bioreactor

Lipase-catalyzed acidolysis of olive oil and caprylic acid was performed in a bench-scale packed bed bioreactor to produce structured lipids (SL). A 1,3-specific lipase, IM 60 from Rhizomucor miehei was used as the biocatalyst. Reaction products were analyzed by reversed phase high-performance liquid chromatography, with an evaporative light scattering detector. Olive oil is characterized by four major clusters of triacylglycerol species with equivalent carbon number (ECN), C44, C46, C48, and C50. Three monosubstituted products and two disubstituted products were detected after the reaction. Monosubstituted products had ECN of C36, C38, and C40, and disubstituted products had ECN of C30 and C32. The effect of solvent, temperature, substrate mol ratio, and flow rate/residence time were studied. Optimal solvent-free production of SL was obtained at a substrate flow rate of 1 ml/min, residence time 2.7 h, temperature 60°C, and mol ratio 1:5 (olive oil/caprylic acid). Fatty acid distribution at the sn-2 position of olive oil was determined by pancreatic lipase hydrolysis as 74.8% oleic acid and 25.2% linoleic acid. SL produced at optimal conditions had 7.2% caprylic acid, 69.6% oleic acid, 21.7% linoleic acid and 1.5% palmitic acid at the sn-2 position.     

固定化脂酶催化合成生物柴油的研究

探讨了酶法制备生物柴油的过程,通过脂肪酶酯化和醇解两种工艺路线合成生物柴油的试验研究,考察了反应条件如醇油比、催化剂用量、反应温度、反应时间等对酯化率和产品纯度的影响.试验表明,采用分批加入甲醇的酯化工艺,酯化率可以达到95%以上;采用醇解工艺菜籽油酯化率达95%以上,产品经GC分析其纯度可达98%以上,固定化酶的半衰期至少达100 d.     

PREPARATION OF STRUCTURED LIPIDS WITH SPECIAL FUNCTIONAL PROPERTIES

Enzymatic acidolysis of rapeseed oil with capric acid was carried out to obtain structured lipids. The reaction was catalyzed by Lipozyme IM lipase from Rhizomucor miehei. The enzyme preparations contained 2.8 and 10% water. The reaction conditions were enzyme load of 8% (w/w total substrates), substrate mole ratio of 1:6 (rapeseed oil:capric acid), and reaction temperature of 65C. The results showed that triacylglycerols (TAG) after transesterification contained mainly oleic, linoleic and linolenic acids (about 90%) in the internal sn-2 position, whereas capric acid was mostly in the external sn-1,3 positions (approximately 40%). The quantity of water in the reaction medium had a significant influence on the yield and quality of the TAG fraction.     

1,2,6-三磷酸-3,4,5-三乙酸肌醇酯的制备及其抗油脂氧化活性研究

植酸水解得到1,2,6-三磷酸肌醇(PP56),PP56与三乙胺反应生成相应的铵盐.以二氯甲烷为溶剂,脂酶Novozyme 435催化,该铵盐与乙酸反应生成1,2,6-三磷酸-3,4,5-三乙酸肌醇酯.以过氧化值(POV)为指标研究不同剂量的1,2,6-三磷酸-3,4,5-三乙酸肌醇酯对菜籽油的抗氧化性能,结果表明:1,2,6-三磷酸-3,4,5-三乙酸肌醇酯对菜籽油具有明显的抗氧化作用且存在剂量效应关系,在浓度为0.06%时其抗氧化能力和0.02%BHT相当.