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101.
酶法水解豆渣制备水解蛋白工艺 总被引:11,自引:0,他引:11
豆渣中淀粉含量少,淀粉酶水解步骤对蛋白提取率影响不大,确定不经淀粉酶水解的水解蛋白制备工艺路线.在复合蛋白酶和风味蛋白酶的添加量均为0.1%(酶与底物的比值)时,研究酶反应的pH、水解时间、水解温度及底物浓度对蛋白提取率的影响,应用正交试验找出最佳水解条件,结果表明:pH为6.0,水解时间3h,水解温度为55℃,底物浓度为1:12(豆渣:水),在此条件下水解,蛋白提取率为55.46%,水解度为9.50%. 相似文献
102.
程念政 《大气与环境光学学报》2006,(2)
介绍了“残留农药速测仪”光电系统的设计依据。重点介绍单色光发生器的光学部件、光路系统和棱镜分光;另外介绍了光电转换器件的选择方法;最后用实验验证了对仪器的稳定性和重现性的影响。 相似文献
103.
王承德 《北京理工大学学报(英文版)》1993,2(1):1-4
对每一个双循环群,存在由两个元素构成的生成元集,使相应的 Cayley 有向图是可Hamiltonian 分解. 相似文献
104.
E. Michael Thurman Imma Ferrer Octavio Malato Amadeo Rodriguez Fern ndez-Alba 《Food Additives & Contaminants》2006,23(11):1169-1178
Traditionally, the screening of unknown pesticides in food has been accomplished by GC/MS methods using conventional library-searching routines. However, many of the new polar and thermally labile pesticides are more readily and easily analysed by LC/MS methods and no searchable libraries currently exist (with the exception of some user libraries, which are limited). Therefore, there is a need for LC/MS libraries that can detect pesticides and their degradation products. This paper reports an identification scheme using a combination of LC/MS time-of-flight (accurate mass) and an Access database of 350 pesticides that are amenable to positive ion electrospray. The approach differs from conventional library searching of fragment ions. The concept consists of three parts: (1) initial screening of possible pesticides in actual market-place fruit extracts (apple and orange) using accurate mass and generating an accurate mass via an automatic ion-extraction routine, (2) searching the Access database manually for screening identification of a pesticide, and (3) identification of the suspected compound by accurate mass of at least one fragment ion and comparison of retention time with an actual standard. Imazalil and iprodione were identified in apples and thiabendazole in oranges using this database approach. 相似文献
105.
Salmain M Caro B Le Guen-Robin F Blais JC Jaouen G 《Chembiochem : a European journal of chemical biology》2004,5(1):99-109
Study of the reaction between the transition organometallic complex 4-ruthenocenyl 2,6-dimethylpyrylium tetrafluoroborate and the enzyme hen egg white lysozyme (HEWL) in solution and by diffusion in crystals was performed by use of a combination of spectroscopic and chromatographic methods. Conjugation involving the lysine residues of lysozyme appeared to occur readily, yielding very stable ruthenocenyl pyridinium adducts with average degrees of incorporation ranging from 0.2 to 1.8 metal complexes per protein molecule, depending on reaction conditions. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) revealed that the protein conjugates were in fact mixtures of unmodified, mono-, di- and sometimes tripyridinium adducts. In combination with reversed-phased HPLC, we were able to show that six different monoruthenocenyl pyridinium adducts were formed in solution. This result was confirmed by trypsin digestion of a ruthenocenyl pyridinium conjugate and MALDI-TOF MS analysis of the peptide mixture, which showed that lysines 1, 13, 33, 96, 97 and 116 were involved in the reaction with the pyrylium complex, lysines 13, 33 and 116 being the major binding sites. In the tetragonal crystal state, no binding of the ruthenium complex was shown to occur at lysine 116, owing to steric hindrance at this particular position. 相似文献
106.
干涉合成孔径雷达复图像配准是合成孔径雷达干涉三维成像技术中的重要步骤之一。为了获得高精确度的测量结果,要求两幅复图像之间配准达到亚像素级配准精确度。讨论了从粗到精的干涉图像对分布配准方法,并基于残差点的生成机理,深入研究了残差点发生概率与配准精度的内在联系,提出利用残差点数目进行干涉纹图质量评估的方法。用所讨论方法处理ERS-1/2获取的某地区数据,取得了满意的配准效果和正确的评估结果。 相似文献
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110.
Anna M. Balinova Rositsa I. Mladenova Deyana D. Shtereva 《Food Additives & Contaminants》2007,24(8):896-901
The effects of storage intervals and of milling procedures on dissipation of deltamethrin residues in post-harvest treated wheat grain were studied with the aim to obtain scientific data on compliance of the processed products with the safety requirements concerning baby foods. The insecticide formulation was applied on stored wheat at a recommended rate of active ingredient of 0.5 mg kg-1 and at a higher rate of 4 mg kg-1, performing the highest protective effect. The dissipation of residues and their distribution in different fractions of the milled grain were studied after various storage intervals, from 7 to 270 days after treatment. Eight fractions—bran, semolina, three types of groats, and three types of flour—were collected after milling of grain and analysed for determination of pesticide residues. The residues were determined by gas chromatography characterized by the limit of determination of 0.005 mg kg-1, low enough for enforcement of the maximum residue level of 0.01 mg kg-1 established by the European Commission Directive for any pesticide in cereal-based foods. Deltamethrin applied post-harvest on wheat as grain protectant was distinguished by low rate of degradation on the grain under practical storage conditions. One hundred and eighty days after treatment at an application rate of 0.5 mg kg-1, the residues were between 0.03 and 0.2 mg kg-1 in the various types of flour. Two hundred and seventy days after treatment at a rate of 4 mg kg-1, the residues in the flour were in the range of 0.4-1.5 mg kg-1. 相似文献