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1.
Anders?Falk?VikbjergEmail author Lifeng?Peng Huiling?Mu Xuebing?Xu 《Journal of the American Oil Chemists' Society》2005,82(4):237-242
The possibilities of producing structured phospholipids between soybean phospholipids and caprylic acid by lipase-catalyzed
acidolysis were examined in continuous packedbed enzyme reactors. Acidolysis reactions were performed in both a solvent system
and a solvent-free system with the commercially immobilized lipase from Thermomyces lanuginosa (Lipozyme TL IM) as catalyst. In the packed bed reactors, different parameters for the lipase-catalyzed acidolysis were elucidated,
such as solvent ratio (solvent system), temperature, substrate ratio, residence time, water content, and operation stability.
The water content was observed to be very crucial for the acidolysis reaction in packed bed reactors. If no water was added
to the substrate during reactions under the solvent-free system, very low incorporation corporation of caprylic acid was observed.
In both solvent and solvent-free systems, acyl incorporation was favored by a high substrate ratio between acyl donor and
phospholipids, a longer residence time, and a higher reaction temperature. Under certain conditions, the incorporation of
around 30% caprylic acid can be obtained in continuous operation with hexane as the solvent.
Presented at the 95th American Oil Chemists' Society Annual Meeting and Expo in Cincinnati, Ohio, May 10, 2004. 相似文献
2.
Quantitation of acyl migration during lipase-catalyzed acidolysis, and of the regioisomers of structured triacylglycerols formed 总被引:1,自引:0,他引:1
Huiling Mu Juha-Pekka Kurvinen Heikki Kallio Xuebing Xu Carl-Erik Høy 《Journal of the American Oil Chemists' Society》2001,78(9):959-964
Various MLM-type (M, medium-chain fatty acids; L, long-chain fatty acids) structured triacylglycerols were produced in pilot-
or small-scale packed-bed reactors by lipasecatalyzed acidolysis. The incorporation and acyl migration of octanoic acid were
measured by gas chromatography and Grignard degradation, and ranged from 39.0 to 48.7% and 0.6 to 9.3%, respectively. Quantitation
of triacylglycerol molecular species was performed by ammonia negative ion chemical ionization (NICI) mass spectrometry (MS).
The proportion of ACN (acyl carbon number) 34 species that contained one C18 fatty acid and two C8∶0′ in samples analyzed, varied from 12.5 to 23.2%. The selected regioisomers MLM and MML within the ACN 34 species group were
quantified by NICI tandem MS (MS/MS) and were in the range of 97.1 to 98.4% and 1.6 to 2.9%, respectively. There was no correlation
between the level of acyl migration during lipase-catalyzed esterification and the level of regioisomers of the selected MLM-type
triacylglycerols in the structured lipid samples. 相似文献
3.
为提高杂醇油的利用率和附加值,研究非水相条件下杂醇油的脂肪酶催化酯化反应,优化其转化为天然酯类香料的工艺条件.结果表明,酶用量、分子筛用量、乙酸加入次数及间隔时间、摇床转速、反应温度、反应时间等因素条件对产物酯的生成有重要影响,采用间歇式加酸、加入适量分子筛吸水剂可明显提高混合酯得率.在正已烷10mL、杂醇油3ml、乙酸1.5mL的反应体系中,正交试验设计优化后的工艺条件(乙酸异戊酯产率最高时):脂肪酶Novozym435FG用量70mg、乙酸分6次加入、加入乙酸间隔时间3h、分子筛用量2g、摇床转速140r/min、反应温度45℃、反应时间36h.该条件下,乙酸异戊酯、乙酸异丁酯和乙酸丙酯的产率分别为90.1%,91.3%,78.1%. 相似文献
4.
糖酯类食品添加剂是同时含有亲水和疏水基团、HLB值为1~16的一种非离子型表面活性剂,具有无臭、无味、无毒及优良的表面性能等特点,在食品工业中具有诱人的应用前景。脂肪酶非水相催化合成糖酯有着化学合成法无可比拟的优点,已引起众多研究者的广泛关注。本文就非水相中催化合成糖酯所用脂肪酶的来源、非水相体系、酶的催化活性、糖酯类食品添加剂的检测方法及其在食品工业中的应用进行了综述,并展望其发展前景。 相似文献
5.
以苦瓜籽油为原料,利用癸酸在脂肪酶Lipozyme RM IM的催化下进行结构修饰,来降低苦瓜籽油中桐酸的含量。选取底物物质的量的比、加酶量、反应温度、反应时间为影响因素,采用响应面分析法进行反应条件优化,得最佳反应条件为底物物质的量的比(苦瓜籽油:癸酸)=1:4、加酶量(占底物质量的质量分数)12.5%、反应温度60℃、反应时间14.8h。在此最优反应条件下得到的新油脂中癸酸含量为47.12%,同时桐酸含量由反应前苦瓜籽油中的56.17%降为25.46%。 相似文献
6.
7.
Jungbae Kim David H. Altreuter Douglas S. Clark Jonathan S. Dordick 《Journal of the American Oil Chemists' Society》1998,75(12):1109-1113
Lipase-catalyzed esterification has been performed in hexane to generate novel mixtures of fatty acid esters from specially
chosen combinations of fatty acids and alcohols. By varying the alcohol and enzyme compositions in the enzymatic reactions,
different ester mixtures were produced, which were further purified and analyzed for ester composition by gas chromatography-mass
spectrometry. Depending on the combination of alcohols and enzymes used, the final ester mixture exhibited significant compositional
variation. These mixtures could be manipulated at the synthesis step, thereby enabling a high degree of product control. Such
manipulation over enzyme-catalyzed ester synthesis in mixtures may be useful in the preparation of ester flavors for use in
the food industry. 相似文献
8.
影响酶法酯交换中甘二酯含量的因素研究 总被引:1,自引:2,他引:1
甘二酯是酶法酯交换过程中重要的中间体.较高的甘二酯含量影响最终产品的纯度,也导致副产物的产生.研究了酶法催化酯交换过程中反应温度、反应时间、水含量、酶用量、底物比对甘二酯含量的影响.实验结果表明,反应体系中酶量是影响甘二酯含量的最大影响因素,且为正相关.在符合产品结构的较优的反应中,甘三酯含量为88.2%,甘二酯含量为6.9%. 相似文献
9.
William?E.?Levinson Tsung?Min KuoEmail author David?Weisleder 《Journal of the American Oil Chemists' Society》2005,82(7):501-504
A novel hydroxylated primary fatty amide was produced from lesquerolic acid by direct amidation with ammonia catalyzed by
immobilized Pseudozyma (Candida) antarctica lipase B (Novozym 435) in organic solvent. The amides of ricinoleic acid and oleic acid were also produced for comparison.
The hydroxy FA were transformed at comparable rates to that of oleic acid. The rate of amide formation was greater for the
longerchain lesquerolic acid than for ricinoleic acid. All products exhibited characteristic primary-amide mass spectrum peaks
with a base peak at m/z 59 and a strong ion fragment at m/z 72. Other peaks present are consistent with cleavage on either side of the hydroxyl position. The mass spectra, together
with 1H and 13C NMR data, suggest that the products of lipase-catalyzed direct amidation of ricinoleic acid and lesquerolic acid are 12-hydroxy-9(Z)-octadecenamide and 14-hydroxy-11(Z)-eicosenamide, respectively. 相似文献
10.
A process for the preparation of food-grade rice bran wax and the determination of its composition 总被引:2,自引:2,他引:2
Shaik?Ramjan?Vali Yi-Hsu?JuEmail author Thengumpillil?Narayana?Balagopala?Kaimal Yaw-Terng?Chern 《Journal of the American Oil Chemists' Society》2005,82(1):57-64
A two-step method was developed for the preparation of food-grade wax. The first step involved the solventdefatting of crude
wax, which gave a dark brown, dry, powdered wax with a m.p. of 75–79°C. The major impurity in the defatted wax was the dark
brown resinous matter. In the second step, the resinous matter was removed by bleaching with sodium borohydride in isopropanol.
This step yielded a pale yellow, odorless wax with purity higher than 99% and with a m.p. of 80–83°C. The resinous matter
was a mixture of aliphatic aldehydes, fatty alcohols, and FA. High-temperature GC analysis of the purified rice bran wax indicated
that it contained 11 major and 9 minor types of saturated wax esters. The major and minor peaks contained C44–C64 and C45–C59 wax esters, respectively. Rice bran wax was mainly a mixture of saturated esters of C22 and C24 FA and C24 to C40 aliphatic alcohols, with C24 and C30 being the predominant FA and fatty alcohol, respectively. The alcohol portion of the wax esters also contained small amounts
of branched and odd carbon number fatty alcohols. 相似文献