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醋酸纤维素固定化脂肪酶催化猪油合成单甘酯 总被引:6,自引:0,他引:6
以醋酸纤维素固定化猪胰脂肪酶催化猪油甘油解反应合成单甘酯,反应温度在猪油熔点附近(32℃),甘油与酶摩尔比为4:1,甘油含水量为4%,反应在20h达到平衡,可获得单甘酯的最高产率,为50.05%。 相似文献
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研究了以CaCO3 粉末为载体吸附法固定化脂肪酶的方法。结果表明 ,当酶的用量为CaCO3 质量的 0 3g g-1,吸附时间 1 5h ,所得固定化酶活最高 ,为 15 8 1UCaCO3/g min。研究了固定化酶催化棕榈油固相甘油解反应合成单甘酯工艺条件 ,结果表明 ,固定化酶加入量为 15 0U/g油 ,甘油与棕榈油摩尔比为 4∶1,甘油中水的含量为 4% ,于2 8℃反应 2 4h ,然后将反应体系的温度降至室温 ( 13℃~ 15℃ ) ,9天后单甘酯的含量达 33 4% ,该固定化酶很容易从反应体系中回收 ,重复使用 5次 ,酶活保留 73 37% 相似文献
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CaCO3粉沫作载体固定化脂肪酶催化合成单甘酯 总被引:4,自引:0,他引:4
研究了以CaCO粉末为载体吸附法固定化脂肪酶的方法。结果表明,当酶的用量为CaCO3质量的0.3g.g^-1,吸附时间1.5h,所得固定化酶活最高,为158.1UCaCO3/g.min,研究了固定化酶催化棕榈油固相甘油解反应合成单甘酯工艺条件,结果表明,固定化酶加入量为150U/g油,甘油与棕榈油摩尔比为4:1,甘油中水的含量为4%,于28℃反应24h,然后将反应体系的温度降至室温(13℃-15℃),9天后单甘酯的含量达33.4%,该固定化酶很容易从反应体系中回收,重复使用5次,酶活保留73.37%。 相似文献
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微乳液体系中脂肪酶催化油脂水解合成单甘酯 总被引:3,自引:0,他引:3
在微乳液体系中脂肪酶催化棕榈油水解可合成单甘酯,最佳条件下,单甘酯的含量为12.91%,此时单甘酯的得率为81.7%。 相似文献
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脂肪酶的固定化是降低其使用成本的有效途径之一.提出了利用亲水/疏水复合膜中的微结构固定化脂肪酶的新思路.首先制备由致密的亲水层和多孔的疏水层组成的醋酸纤维素/聚四氟乙烯(CA/PTFE)复合膜,然后利用复合膜的特殊微结构,用超滤的方法实现了脂肪酶的固定化.扫描电镜照片结果表明,大部分被截留的酶位于复合膜的界面处.制备得到的固定化酶膜应用于水解橄榄油的反应,其最高催化活力达到1.24 μmol FFA·min-1·cm-2,大大高于文献报道值.同时研究了固定化脂肪酶膜的催化动力学,考察了亲水层厚度和脂肪酶负载量对固定化效果的影响,优化了固定化条件.在经过10次(50 h以上)的重复使用后,固定化酶膜的活力仅降低了20%. 相似文献
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固定化脂肪酶催化菜籽油合成蜡酯 总被引:2,自引:0,他引:2
以菜籽油、鲸蜡醇为原料,采用实验室自制的固定化Candidia sp.99-125脂肪酶分别在有机溶剂和无溶剂体系下合成了蜡酯,在两种体系下对影响蜡酯合成的各种因素进行了比较研究,研究表明:以正己烷为反应介质,在40℃条件下反应12h,油醇摩尔比1∶2,酶量15%(质量分数,上同),水含量7.5%,蜡酯产率可达85.87%;无溶剂体系中在50℃条件下反应20h,油醇摩尔比1∶1.5,蜡酯产率可达80.68%。通过流加鲸蜡醇可以提高酶的使用寿命。 相似文献
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脂肪酶催化合成单脂肪酸甘油酯 总被引:2,自引:0,他引:2
对脂肪本矣合成单甘酯中的催化作用作了综述。介绍了有机溶剂、反相胶束和无溶剂固相等反应体系中用不同脂肪酶对油脂选择水解、脂肪酸的酯化或脂肪酸酯与甘油的转酯反应、油脂甘油解以及甘油基团保护反应等合成方法。2 相似文献
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醋酸丙酸纤维素的合成与表征 总被引:4,自引:0,他引:4
采用非均相催化酯化法合成醋酸丙酸纤维素(CAP),研究了反应时间、温度和催化剂用量对CAP乙酰和丙酰取代度、特性粘度的影响,发现反应温度、反应时间和催化剂浓度增加虽可使产物的取代度增大,但粘度降低,得到优化的反应条件为:催化剂用量1%(wt,相对于纤维素),反应温度60℃,反应时间2 h。酯化反应使纤维素的结晶度降低。 相似文献
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Herein a novel process to synthesize cellulose acetate (CA) is reported in a solvent-free ball-milling reactor in the presence
of solid superacid SO4
2−/ZrO2 as green catalyst. FT-IR and H1-NMR spectra reveal that the maximum degree of substitution (DS) of formed cellulose acetate can achieve 1.8, and the DS depends
on the reaction time. This method provides a new environmental benign and simple way to synthesize cellulose acetate. 相似文献
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The high performance liquid chromatography method (HPLC) with ethyl cellulose/cellulose acetate (EC/CA) blends and EC as column packing material, and small molecular weight compound as probe molecules was employed to measure the retention volume (VR) and equilibrium distribution coefficient (K) of both inorganic and organic solutes. The interfacial separation properties of EC/CA blends were characterized by the HPLC data. The effects of the blends on the interfacial adsorption properties, hydrophilicity, affinity, polar and non-polar parameters of EC membrane materials were studied subsequently. The research results indicate that the interfacial adsorption properties and hydrophilicity of EC have been improved by solution blending with CA. The alloys are superior to EC in the separation efficiency for non-dissociable polar organic solute. The EC/CA alloy (80:20, w) is suitable for desalting and desaccharifying. 相似文献
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Gangadhara Parigi Ramesh Kumar Vishweshwaraiah Prakash 《Journal of the American Oil Chemists' Society》2009,86(8):773-781
Porcine pancreatic lipase (PPL) has been used as a biocatalyst for many years and is one of the most widely used enzymes for
biotechnological applications; however, it is a rather complex mixture with various active enzymes. The present study has
been undertaken to determine the effects of polyols and sugars (cosolvents) on the thermal stability of PPL preparation. The
thermal stability of PPL exposed to 60°C for 10 min was enhanced in the presence of cosolvents in terms of both residual specific
activity and conformational stability. Thermal denaturation, changes in circular dichroism, fluorescence spectra, apparent
kinetic parameters, activity, and preferential interaction parameter of PPL preparation are discussed in terms of contributions
to the mechanism of thermal stability and the activity enhancement. Partial specific volume measurement of PPL in the presence
of cosolvents is presented for the first time. The preferential interaction parameter (ξ
3) was negative in all cosolvents used, and maximum hydration was observed in the presence of trehalose, where the preferential
interaction parameter was −0.076 g/g. The observed increase in the thermal stability of PPL preparation in the presence of
cosolvents is due to the preferential hydration of the enzyme. 相似文献