共查询到19条相似文献,搜索用时 203 毫秒
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采用动物蛋白水解酶对云南盘鮈进行酶水解,通过正交实验法确定了酶水解条件。结果表明,酶水解的最适条件为:温度50℃,pH7.0,时间3h,加酶量0.5%,固液比1∶2.5。在该条件下盘鮈肉蛋白的水解度为32.85%。氨基酸分析表明,游离氨基酸含量36.47mg/mL,必需氨基酸14.42mg/mL,占39.54%。尤其是亮氨酸、缬氨酸、苏氨酸、赖氨酸含量丰富,为低值鱼深加工研究提供理论依据。 相似文献
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报道了一种新颖的串联酶解(先酶I后酶II)耦合超微粉碎方法,并系统研究了其对蔗渣酶水解的促进作用. 通过对三种酶解方法(单酶I、单酶II、先酶I后酶II) 的比较发现,串联酶解对蔗渣酶解最为有效. 超微粉碎能破坏蔗渣细胞结构,使纤维素充分暴露出来便于酶解.在串联酶解耦合超微粉碎模式下,蔗渣在反应温度50 oC,pH=4.8,酶I(7.5 FPU/g底物)和酶II(5.0 FPU/g底物),摇床速率1200 r/min条件下反应72 h后,酶水解能得到65%的还原糖浓度,其中葡萄糖选择性为90.1%. 相似文献
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Ying Wang Lei Zhang Ying-Chao Ji Hong Li Qiu-Hong Wang Bo Yuan 《Journal of Macromolecular Science: Physics》2017,56(4):203-212
Plasma acid was obtained by treating distilled water with a dielectric barrier discharge (DBD) at atmospheric pressure. The tentative relationship between discharge conditions and pH value of the plasma acid was investigated. In order to optimize the hydrolysis conditions of microcrystalline cellulose with the plasma acid, an orthogonal experiment was carried out and the colorimetric determination of 3,5-dinitro-salicylic acid was applied to measure the concentration of total reduced sugar (TRS). The results showed that the pH value of the plasma acid was related to the discharge time. The acidity of the plasma acid was maintained for several hours and then faded gradually. The microcrystalline cellulose was hydrolyzed effectively by the plasma acid and the optimal hydrolysis conditions were as follows: pH 1.42 of the plasma acid, hydrolysis temperature of 80°C and hydrolysis time of 60 min. Under these conditions, the microcrystalline cellulose with polymerization degree of 200–300 was hydrolyzed completely to produce monosaccharides, including xylose and glucose with the mole ratio of 1:35, as shown by high-performance liquid chromatography (HPLC) analysis. Moreover, the hydrolysis of luffa cellulose with polymerization degree of 500–600 was also carried out. The luffa cellulose was hydrolyzed completely to produce monosaccharides including xylose, mannose and glucose with mole ratio of 6.7:1:218. Therefore, it could be concluded that the main hydrolysis product of both types of cellulose was glucose. The glucose yield of microcrystalline cellulose was 46%, whereas for luffa cellulose it was 41%. This method was an environmentally friendly and effective method to hydrolyze cellulose. 相似文献
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Xin Jin Ju-Fang Li Ping-Ying Huang Xu-Yan Dong Lu-Lu Guo Yuan-Cheng Cao Yuan-Di Zhao Hong Chen 《Journal of magnetism and magnetic materials》2010,322(14):2031-2037
(3-aminopropl) triethoxysilaneand modified magnetic nanoparticles with the average diameter of 25.4 nm were synthesized in water-phase co-precipitation method. And then these nanoparticles were covalently coupled with alkaline protease as enzyme carrier by using 1,4-phenylene diisothlocyanate as coupling agent. Experiments showed that the immobilized protease can keep the catalytic bioactivity, which can reach to 47.8% when casein was served as substrate. Results showed that the catalytic activity of immobilized protease on these magnetic nanoparticles could retain 98.63±2.37% after 60 days. And it is more stable than the free protease during the shelf-life test. The enzyme reaction conditions such as optimum reaction temperature and pH are the same as free protease. Furthermore, mix-and-separate experiments showed that the immobilized protease could be recycled through the magnetic nanoparticles after the biocatalysis process. When the rapeseed meals were used as substrate, the degree of hydrolysis of immobilized alkaline protease achieved 9.86%, while it was 10.41% for the free protease. The macromolecular proteins of rapeseed meals were hydrolyzed by immobilized protease into small molecules such as polypeptides or amino acids. Thus, a novel efficient and economic way for the recycling of enzymes in the application of continuous production of active peptides was provided based on these magnetic nanoparticles. 相似文献
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通过原子吸收光谱法研究了在不同pH值、吸附剂量、吸附质浓度和吸附时间条件下磷酸酯化改性梨渣吸附Cr(Ⅵ)离子的效果。溶液初始pH 4.5时,Cr(Ⅵ)离子的吸附达到最大值;酯化梨渣≥10g.L-1能除去Cr(Ⅵ)为100μg.L-1溶液中的86.5%的Cr(Ⅵ)离子。酯化梨渣对Cr(Ⅵ)离子的吸附符合Langmuir等温模型,其最大吸附能力为67.56μg.g-1。Cr(Ⅵ)离子达到吸附平衡的时间为90min,准一级反应动力学方程可描述酯化梨渣对Cr(Ⅵ)离子的吸附过程。 相似文献
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以超声萃取-酸水解-超声萃取进行预处理,结合RP-HPLC测定黄姜中薯蓣皂甙元含量。色谱条件为:采用AglilengtHC-C18色谱柱,流动相为甲醇∶水=95∶5(V∶V),流速为1.0mL/min,UV检测波长为203nm。结果表明,在40—1000μg/mL范围内,薯蓣皂甙元峰面积与其质量浓度具有良好的线性关系(r=0.9996),样品平均加标回收率为99.8%,RSD为1.1%。与直接酸水解-萃取预处理方式进行对比,本方法测得薯蓣皂甙元含量提高了32%。采用本方法对黄姜芽,根茎,表皮及不定根中的薯蓣皂甙元含量进行测定:根茎1.69%,芽0.19%,表皮0.15%,不定根部分含量为0.36%。 相似文献
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以砀山梨渣为原料,经磷酸酯化改性,制备一种酯化梨渣阳离子吸附剂,用批次实验法研究了其在不同实验条件下(pH值、吸附剂量、吸附质浓度和吸附时间)对金属锌离子的吸附性能。结果表明,溶液pH=3.5时,锌离子吸附达到最大值;酯化梨渣≥5g.L-1能除去锌离子为100mg.L-1溶液中的96%锌离子。改性梨渣对锌离子的吸附符合Langmuir吸附等温线模型,最大吸附能力为28.986mg.g-1。锌离子达到吸附平衡的时间为30min;准一级反应动力学方程y=-0.0615x+2.4437(r2=0.9921)描述锌离子在改性梨渣上的吸附过程。 相似文献
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在酸性介质中,F e(Ⅲ)能够催化H2O2氧化中性红褪色反应,而对苯二酚和邻苯二胺都能阻抑该催化氧化褪色反应的速度。但二者存在一定的速率差异,且吸光度的加和性不佳。结合人工神经网络提出了一种能同时测定对苯二酚和邻苯二胺的新方法。研究了最佳反应和测定条件,结果表明:1.0×10^-3m o.lL-1中性红溶液用量为0.8mL;30%H2O2用量为0.6mL;0.100g.L-1F e(Ⅲ)标准溶液用量为0.5mL;0.06m o.lL-1HC l用量为0.8mL;反应时间为6m in;反应温度为75℃时为最佳反应和测定条件。用于混合样品及河水中对苯二酚和邻苯二胺的测定,混合样品中对苯二酚和邻苯二胺回收率分别为95.6%—104.0%、97.8%—104.4%。河水中对苯二酚和邻苯二胺加标回收率均为105%,5次平行测定相对标准偏差分别为3.2%和2.5%。结果满意。 相似文献
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采用Fenton试剂对模拟染料废水的降解效果进行研究。结果表明,H2O2投加量、Fe2+投加量、pH值条件、超声处理时间的改变对染料废水的处理效果影响很大。对酸性染料:当pH为4.5,30%H2O2投加的体积分数为30mL/L,Fe2+投加的质量浓度为400mg/L,反应时间为40min时为降解反应的最佳操作条件。对碱性染料,正交试验表明当pH为4、30%H2O2投加的体积分数16mL/L、Fe2+投加的质量浓度为300mg/L、反应时间为60min时为降解反应的最佳操作条件,其降解率达98.46%,COD的去除率达到96.7%。 相似文献