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Extraction,Composition and Functional Properties of Pennycress (Thlaspi arvense L.) Press Cake Protein
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Mila P. Hojilla‐Evangelista Gordon W. Selling Mark A. Berhow Roque L. Evangelista 《Journal of the American Oil Chemists' Society》2015,92(6):905-914
This study compared two methods for extracting the protein in pennycress (Thlaspi arvense L.) press cake and determined the composition and functional properties of the protein products. Proteins in pennycress press cake were extracted by using the conventional alkali‐solubilization–acid‐precipitation (AP) method or saline‐based (SE) procedure (0.1 M NaCl at 50 °C). The extraction method has a major influence on the purity and functional properties of press cake protein products. AP had a lower protein yield (23 %) but much higher purity (90 % crude protein) compared with SE (45 % yield, 67 % crude protein). AP protein isolate had high foam capacity (120 ml), high foam stability (96 % foam volume retention) and high emulsion stability (24–35 min), and it was resistant to heat denaturation (3 % loss of solubility at pH 2 and pH 10). On the other hand, SE protein concentrate showed remarkably high solubility (>76 %) between pH 2 and 10 and exceptional emulsifying activity (226–412 m2/g protein), but was more susceptible to heat denaturation at pH 7 and pH 10 (65–78 % loss of solubility). These results strongly demonstrate that higher purity pennycress press cake protein can be produced by either saline extraction or acid precipitation and have functional properties that are desirable for non‐food uses. 相似文献
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主要对以含镁高的工业硫酸锰溶液为原料制备高纯四氧化三锰时的沉淀工艺条件进行研究。通过实验测定氢氧化物沉淀时溶液中锰、镁离子浓度和计算沉淀物中镁与锰的质量比,研究了硫酸锰溶液的初始浓度、沉淀pH、反应温度对锰、镁离子沉淀的影响。结果表明,当硫酸锰溶液的锰质量浓度为40 g/L(镁质量浓度为1.56 g/L),选择终点pH为9.0,反应温度为40 ℃时,锰离子的沉淀率可达90%,氧化得到的四氧化三锰产品中锰元素质量分数为71%,镁元素的质量分数为2×10-4,锌元素质量分数为1.26×10-4,其他金属元素质量分数均小于7×10-5,基本能达到四氧化三锰产品质量要求。 相似文献
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Effect of pH on fractional precipitation for pre-purification of paclitaxel from plant cell cultures
Fractional precipitation is a simple, efficient method for pre-purifying paclitaxel from plant cell cultures of Taxus chinensis. The pH, a key process variable in fractional precipitation, was optimized in terms of the yield and purity of paclitaxel
with a fixed methanol concentration in water (61.5%, v/v), paclitaxel content in the crude extract (0.5%, w/v), and storage
time (14 hr). The maximum yield (∼99%) and purity (∼84.4%) of paclitaxel were obtained at pH 8.0 with potassium phosphate
buffer. The precipitate from fractional precipitation was an amorphous state paclitaxel by analysis of XRD and SEM. Also,
the particle size distribution of dried precipitate was a range of approximately 119–411 μm. The use of fractional precipitation
in the pre-purification process allowed for rapid and efficient separation of paclitaxel from interfering compounds, and dramatically
increased the yield and purity of the crude paclitaxel for subsequent purification steps. 相似文献
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对中国几家湿法炼锌厂净化阶段产生的结晶渣进行X射线衍射分析,确定了湿法炼锌过程产生的碱式硫酸锌的结构是ZnSO4·3Zn(OH)2·5H2O,从而否定了是ZnSO4·3Zn(OH)2的传统观点,表明碱式硫酸锌的溶解度与水的活度有关。采用高温硫酸锌溶液中加入氧化锌粉末的方法制得与炼锌厂碱式硫酸锌结晶渣晶型一致的产物。同等硫酸锌浓度、pH条件下,碱式硫酸锌溶解度随着温度的升高而升高。研究表明,在锌质量浓度为168 g/L、pH为5.2的中性浸出液中,碱式硫酸锌析出温度为60.6 ℃±0.4 ℃,80 ℃降到40 ℃的析出量为4.4 g/L。 相似文献
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针对转底炉氧化锌粉附加值低的问题,以转底炉氧化锌粉为研究对象,以氯化胆碱-二水合草酸(CC-OA)低共熔溶剂为研究体系,运用低共熔溶剂的选择溶解性对氧化锌粉进行提纯并制备纳米氧化锌,对纳米氧化锌晶粒生长的动力学进行了研究。氧化锌粉水洗处理的最优方案:水洗温度为50 ℃、水洗时间为3 min、液固体积质量比为3 mL/g。低共熔溶剂处理氧化锌粉得到的前驱体为二水合草酸锌(ZnC2O4·2H2O),根据唯象方程计算得出焙烧温度、焙烧时间与粒径的关系,实现了特定粒径纳米氧化锌的制备。在焙烧温度为400 ℃、焙烧时间为2 h条件下,制备的氧化锌纯度可达99.768%,其形貌呈现较为均匀的球状并聚集在一起,平均粒径为28.5 nm,且粒径主要分布在10~100 nm。 相似文献
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研究了采用酸溶置换法回收废甲醇催化剂中铜和锌的工艺,并着重对酸溶、置换、沉锌等环节进行了改进。探讨了回收废催化剂中铜和锌的过程中,废催化剂粒度、煅烧温度、酸溶的硫酸用量及质量分数、酸溶时间、锌置换铜的用量及时间、焙烧铜粉温度及时间、氧化铜与硫酸反应的时间及温度、沉锌时pH对锌回收率的影响,得出了适宜的工艺条件。在适宜工艺条件下,可以制备出产品纯度与附加值高的活性氧化锌和五水硫酸铜,回收率分别达94.3%与93.7%,产品质量分别达到GB/T3185-1992和GB437-1980标准,具有较好的经济效益和社会效益,市场前景广阔。 相似文献
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纳米氧化锌的制备与应用 总被引:7,自引:0,他引:7
纳米氧化锌作为一种功能材料,有着许多优异的性能和广泛的应用价值。对纳米氧化锌在国内外的研究现状、制备技术(固相法、液相法和气相法)及其应用状况进行了较为系统的评述,并提出了进一步研究的方向,对纳米氧化锌的形成机理及微观结构进行探讨,寻求行之有效的制备高纯、均匀纳米氧化锌的方法,以及制备各种性能的氧化锌粉体。 相似文献
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Sang‐Hyun Pyo Moon‐Suk Kim Jin‐Suk Cho Bong‐Kyu Song Byung‐Hee Han Ho‐Joon Choi 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(10):1162-1168
Paclitaxel was purified from cell cultures of Taxus chinensis by a combination of extraction, low‐pressure chromatography, precipitation and HPLC. A crude extract (purity 6.9%) was obtained by methanol extraction of plant cell cultures, followed by liquid–liquid extraction using dichloromethane. The extract was purified to greater than 32% with a 97% step yield by low‐pressure chromatography. After acetone/pentane precipitation, the resulting purity and step yield were 75.8% and 97.4%, respectively. High performance liquid chromatography steps, which were composed of an HPLC step with column‐packed ODS and an HPLC step with column‐packed silica, were applied to give over 99.5% purity with high yield. Amorphous paclitaxel with a fine particle size, which has a solubility advantage compared with the stable crystalline form, was obtained by dissolving in dichloromethane, followed by spray‐drying. Copyright © 2004 Society of Chemical Industry 相似文献
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《分离科学与技术》2012,47(1-4):775-792
Abstract Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated to effectively remove hydrogen sulfide with various metal oxide sorbents at high temperatures and pressures. Metal oxide sorbents such as zinc titanate oxide, zinc ferrite oxide, copper oxide, manganese oxide, and calcium oxide were found to be promising sorbents in comparison with other removal methods such as membrane separation and reactive membrane separation. The removal reaction of H2S from coal gas mixtures with zinc titanate oxide sorbents was conducted in a batch reactor. The main objectives of this research are to formulate promising metal oxide sorbents for removal of hydrogen sulfide from coal gas mixtures, to compare reactivity of a formulated sorbent with a sorbent supplied by the Research Triangle Institute at high temperatures and pressures, and to determine effects of concentrations of moisture contained in coal gas mixtures, and to determine effects of concentrations of moisture contained in coal gas mixtures on equilibrium absorption of H2S into metal oxide sorbents. Promising durable metal oxide sorbents with high-sulfur-absorbing capacity were formulated by mixing active metal oxide powders with inert metal oxide powders and calcining these powder mixtures. 相似文献
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采用中心复合设计的响应曲面法优化了乙醇/硫酸铵双水相体系从丹参粗提液中分离丹酚酸B的工艺参数,并对放大效果进行了对比研究。结果表明,在确定pH2.0和30℃的条件下,当硫酸铵和乙醇质量分数分别为20%和29%时,丹酚酸B的分配系数最大为58.7,回收率为97.3%。上相加乙醇脱除硫酸铵,减压浓缩、干燥,丹酚酸B的纯度为57.4%。与小试相比,放大40倍后,分配系数(59.3)、回收率(98.2%)和纯度(58.6%)均无显著差异(p<0.05)。500g丹参,经煮提,双水相萃取,脱硫酸铵,氯仿脱脂,乙酸乙脂萃取,可得26.1g浸膏,丹酚酸B的纯度为78.1%,总回收率为87.0%。因此,双水相萃取可以作为从丹参粗提液中规模分离丹酚酸B的有效手段。 相似文献
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以七水硫酸锌、碳酸氢铵为原料,通过液相沉淀法合成纳米氧化锌前体,并焙烧获得纳米氧化锌。本文采用XRD、TG-DSC、TEM、BET等测试手段对纳米氧化锌及其前体进行表征,研究了焙烧温度对所制备氧化锌形貌、晶型及脱硫活性的影响,结果表明:所获得的碱式碳酸锌为不规则纳米晶,晶粒尺寸约为2~10nm;在不同的焙烧温度下所获得的纳米氧化锌的综合性能存在较大差异,其中在焙烧温度300℃处理所得纳米氧化锌综合性能较高,其晶粒尺寸为5~10nm之间,结晶度较完整,比表面积为41.41m2/g,在220℃脱硫活性较高,穿透硫容>25%;随着焙烧温度的提高,纳米氧化锌的晶化程度加大,表面性质被破坏,比表面积急剧下降,颗粒团聚严重;焙烧温度太低,则纳米氧化锌前体分解不完全,影响其纯度。 相似文献
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采用泡沫分离法分离纯化无患子皂苷溶液,收集溢出分离柱的泡沫液,采用紫外分光光度计分别测定原液和泡沫液的皂苷含量,通过富集比、回收率以及纯度表征分离效果。结果表明:在进料浓度为 2.0 g/L、进料量为 150 mL、气速为 32 L/h、温度为 30 ℃、pH值为4.3条件下,富集比可达到2.153,收率与纯度分别达到 79.19 % 和 74.68 %。 相似文献
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《分离科学与技术》2012,47(15):3187-3224
Abstract Hydroxyapatite (HAP) is a calcium phosphate compound with the chemical formula Ca5(PO4)3OH. This compound is especially significant in biomedical applications since it resembles the mineral constituents of the hard tissue in the human body. Its biocompatibility, castability, and sinterability make it a very attractive material for simulating bones and therefore for implantations. The objective of this study was to produce HAP with a high purity and to determine quantitatively the exact percentage of HAP in the synthesized powder. Hydrothermal methods have been used to produce HAP. In the present work, Hydroxyapatite powder was produced using the chemical precipitation method in a batch and semi‐batch modes of operation. The effect of temperature, pH, and reactant addition rates on the mean particle size was studied. Results showed a maximum in the mean particle size at pH 9, while a minimum was observed at around 45°C. As the reactant addition rate increased the mean particle size increased as well. The purity of the obtained powder was characterized using both quantitative and qualitative techniques. The quantitative results were performed using the powerful Rietveld refinement method. The quantitative results were obtained for three samples. Results showed that pure HAP was produced at a temperature of 85°C, pH 9 and reactant addition rate of 1.3 mL/min. 相似文献
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Tanhia Hernandez‐Mireles Marco Rito‐Palomares 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(6):989-996
A simplified process for the primary recovery and purification of B‐phycoerythrin (BPE) from Porphyridium cruentum exploiting aqueous two‐phase systems (ATPS) and isoelectric precipitation was developed in order to reduce the number of unit operations and benefit from increased purity and yield of the protein product. Evaluation of the partitioning behaviour of BPE in polyethylene glycol (PEG)/sulphate, PEG/dextran and PEG/phosphate ATPS was carried out to determine under what conditions the BPE and contaminants concentrated into opposite phases. An additional stage of isoelectric precipitation at pH 4.0 after cell disruption resulted in an increase in purity of the target protein from the BPE crude extract and enhanced the performance of the subsequent ATPS. PEG1000/phosphate ATPS proved to be suitable after isoelectric precipitation for the recovery of highly purified (defined as absorbance ratio A545 nm/A280 nm > 4.0) BPE with a potential commercial value as high as US$ 50/mg. An ATPS extraction stage comprising 29.5% (w/w) PEG1000, 9.0% (w/w) phosphate, a volume ratio (Vr) equal to 1.0, a system pH of 7.0 and loaded with 40% (w/w) of the BPE extract generated by precipitation allowed BPE recovery with a purity of 4.1±0.2 and an overall product yield of 72% (w/w). The purity of BPE from the crude extract increased 5.9‐fold after isoelectric precipitation and ATPS. The results reported herein demonstrate the benefits of the practical application of isoelectric precipitation together with ATPS for the recovery and purification of BPE produced by P. cruentum as a first step in the development of a commercial purification process. Copyright © 2006 Society of Chemical Industry 相似文献
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为了实现磷化渣碱溶后所得废液的综合利用,采用中和沉淀法和硫化钠沉淀法去除磷化渣废液中的杂质锌,对中和沉淀法和硫化钠沉淀法的工艺条件进行优化,并由此设计磷化渣废液除锌制备高纯度磷酸三钠的生产工艺。对于中和沉淀法,在反应体系pH=8.85,反应时间为10 min时,Zn2+去除率可达97.96%;对于硫化钠沉淀法,在反应体系pH=6.85,硫化钠投加量与Zn2+的摩尔比为1:1,反应时间为10 min时,Zn2+去除率可达99.80%。相比于中和沉淀法除锌制备磷酸三钠工艺,硫化钠沉淀法除锌制备磷酸三钠工艺具有更高的磷酸三钠纯度,为98.85%,固相产品中Zn2+含量更低,仅为0.0004%,符合化工行业分析纯标准。该工艺大幅度地回收了磷化渣废液中的PO43-离子和Na+离子,为实现磷化渣综合利用的工业化提供新思路。 相似文献
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《分离科学与技术》2012,47(16):2366-2372
Immunoglobulin of egg yolk (IgY) was separated from fresh hen eggs by three steps, water dilution, salt-out precipitation, and hydrophobic charge induction chromatography (HCIC). In the purification step, HCIC was used as a novel technology and two chromatographic operation modes, packed bed and expanded bed, were compared to improve the separation efficiency. For packed bed mode, IgY were separated with the purity of 92% and the recovery of 58.4% at the operation condition of pH 7.5 and sample (total protein concentration of 11.6 mg/mL, IgY purity of 31%) loading of 0.2 mL/mL adsorbent. For expanded bed mode, a similar purity of 90% and the recovery of 59.5% were found at the fluid velocity of 500 cm/h and same sample loading of 0.24 mL/ mL adsorbent at pH 7.5. The results demonstrated that HCIC in expanded bed mode is a potential platform technology for antibody separation both in high efficiency and low cost. 相似文献
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