裸藻蛋白泡沫分离的工艺优化及功能特性分析

以裸藻蛋白液为原料，通过泡沫分离法提取裸藻蛋白，以回收率和富集比为指标，通过单因素和响应面设计探究pH、装液量、温度、稀释倍数对裸藻蛋白的回收率和富集比的影响。同时研究了裸藻蛋白的功能特性，又采用傅里叶红外光谱和双光束紫外-可见分光光度计对蛋白进行结构分析，通过Peakfit Version软件对蛋白的二级结构进行鉴定，并通过氨基酸分析仪测定了裸藻蛋白的氨基酸组成。结果表明：裸藻蛋白泡沫分离的最佳条件为： pH5.5，装液量300 mL，温度30 ℃，稀释倍数15 倍，在此条件下的蛋白回收率为94.27%，富集比为4.18。蛋白的持水量在60 ℃最大，为7.27 g/g，持油量在40 ℃最大，为14.74 g/g。裸藻蛋白的乳化能力、乳化稳定性、起泡性、泡沫稳定性均随着质量分数的增大呈现先增加后减小的趋势。FT-IR和UV显示裸藻蛋白有典型的蛋白峰，它的二级结构表示裸藻蛋白以β-折叠为主。蛋白中必需氨基酸含量和疏水性氨基酸含量为35.28%和50.81%。     

复合酶协同超声提取藜麦皂苷及其抗氧化性

采用复合酶协同超声提取藜麦种皮皂苷,并对其抗氧化活性进行了测定。以藜麦皂苷的提取率为指标,考察了酶配比m(纤维素酶)∶m(果胶酶)、酶用量、酶解温度、pH、酶解时间对藜麦皂苷提取率的影响,并用响应面法进行了优化。得到最佳工艺条件为:总酶用量(以藜麦种皮质量为基准,下同)为1.5%,酶配比m(纤维素酶)∶m(果胶酶)为3∶2,酶解温度为50.5℃,pH为5.5,酶解时间为0.25 h。在该条件下,藜麦皂苷的提取率较高,达到85.32%;该法对藜麦种皮皂苷的提取率比单一纤维素酶提取率(81.56%)高4.41%,比单一果胶酶提取率(82.20%)高3.66%,比单独超声提取率(73.07%)高16.76%。采用清除1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的能力,分析藜麦皂苷的抗氧化活性,结果表明,藜麦皂苷具有显著的抗氧化活性,且与皂苷的质量浓度呈剂量依赖性。     

超声波处理对麦胚清蛋白结构和功能性质的影响

研究了超声波功率和处理时间对麦胚清蛋白的紫外光谱、荧光光谱、表面疏水性、溶解度、起泡性能、乳化性能的影响. 结果表明,超声波处理对麦胚清蛋白的紫外和荧光光谱有明显的影响,其溶解度在超声波功率1800 W时最高,比对照组提高了96.2%;在600 W的表面疏水性和乳化性、900 W的起泡性和起泡稳定性最高,分别比对照组提高了16.8%, 12.5%, 18.8%和6.0%;处理时间为20 min时的溶解度及10 min时的表面疏水性、起泡性、起泡稳定性、乳化性达到最大,分别比对照组提高了101.3%, 22.1%, 15.0%, 21.9%和12.7%. 但超声波处理降低了麦胚清蛋白的乳化稳定性.     

泡沫相部分水平泡沫分离塔强化分离牛血清蛋白的工艺研究

为了加强泡沫相排液,提高目的产物的富集比,设计了一种新型泡沫分离塔即泡沫相部分水平泡沫分离塔.以传统泡沫相垂直泡沫分离塔为对照塔,以牛血清蛋白(BSA)为体系,考察了表观气速、装液量、物料初始浓度和初始pH对牛血清蛋白(BSA)富集比和回收率的影响.结果表明泡沫相部分水平泡沫分离塔有效减小了泡沫相排液的阻力,提高了BS...     

藜麦(Chenopodium quinoa)内生菌LMJB-14的鉴定与生防促生功能研究

采用平板对峙法,从藜麦内生菌中筛选出对链格孢属(Alternaria sp.)、镰孢菌属(Fusarium sp.)、刺盘孢属(Colletotrichum sp.)3种常见植物真菌性病害具有较强拮抗作用的细菌,通过菌悬液浸种实验测定其对藜麦种子的促生效果,结合形态学特征、生理生化特征、基因测序分析以确定其分类学地位....     

大豆蛋白废水中乳清蛋白的泡沫分离实验

采用泡沫分离法回收大豆蛋白废水中蛋白,考察了pH值、气体的流速、进料浓度、液柱和泡沫层高度等因素对分离效果的影响.低进气速度、高泡沫层高度、适当的pH值以及低进料浓度有利于较好的分离.结果表明:当进料浓度为0.54 g/L、pH值为5、泡沫层与液池高度比4∶1,通气量为15.0 L/h 时,富集比可以达到3.25;当进料浓度为0.54 g/L、pH值为5、泡沫层与液池高度比3∶1,通气量为15.0 L/h,此时脱除率可以达到48.5%.     

猪肺肝素钠提取工艺优化、分离与初步鉴定

该文研究了中心组合设计和响应面分析优化猪肺肝素钠的提取工艺,通过D-254树脂交换吸附、沉淀剂除蛋白质、乙醇沉淀以及DEAE-Sephasoe fast flow离子交换柱层析纯化得到高纯度的猪肺肝素钠,最后采用琼脂糖凝胶电泳、红外光谱、紫外光谱和核磁共振波谱等对其进行初步鉴定。猪肺肝素钠的最佳提取工艺参数为:提取温度53℃,时间4 h,pH=8.5。粗品和纯化后产品的提取率分别为0.81%和0.05%,羊血浆法测定粗品和纯化后产品效价分别为6.5 U/mg和108.3 U/mg。红外光谱显示,纯化后样品在890 cm-1和940 cm-1处出现肝素钠特征吸收峰,紫外光谱最大吸收波长为205 nm,结合琼脂糖凝胶电泳和核磁共振波谱证明用上述方法制备的纯化后的样品为肝素钠。     

泡沫分离法分离桔梗皂苷的工艺研究

采用间歇式泡沫分离法对桔梗提取液中的桔梗皂苷予以分离工艺条件研究;实验以富集比、回收率以及带液率为指标衡量分离效果,在单因素试验基础上,通过正交试验法,获得桔梗皂苷的最佳分离条件。结果表明分离桔梗皂苷的最佳工艺条件为:进料浓度0.014 mg/m L,气体流速700 m L/min,温度30℃,表面活性剂用量(0.505 mg/m L)30 m L,回收率为77.58%,富集比为2.50,带液率为21.67%。因此泡沫分离桔梗皂苷是一种简单、有效、可行的分离方法。     

秦巴山区新鲜粉葛淀粉的提取工艺优化及其性质研究

以淀粉提取率为评价指标,采用超声波辅助碱法提取秦巴山区新鲜粉葛中的淀粉,在单因素实验的基础上,采用响应面法优化提取工艺,并采用扫描电镜、红外光谱及紫外分光光度法等对淀粉颗粒的形貌、结构及性质进行研究,比较了超声波辅助碱法、常规碱法及超声波辅助水法对粉葛淀粉性质的影响。结果表明,超声波辅助碱法提取新鲜粉葛淀粉的最佳工艺条件为:石灰水pH值9、料液比1∶3(g∶mL)、超声功率100 W、超声温度30℃、超声时间28 min、浸泡时间1 h,在此条件下,粉葛淀粉的提取率高达71.42%,透光率为13.10%,黄酮含量为949.72 mg·(100 g)~(-1)。响应面法优化秦巴山区新鲜粉葛淀粉的提取工艺具有可行性,且相比于常规碱法和超声波辅助水法,超声波辅助碱法提取的淀粉的透明度和黄酮保留量更高,为秦巴山区粉葛保健食品的研究与开发提供了技术参考。     

响应面分析法优化萃取分离冷轧磁过滤产物工艺

以萃取法分离钢厂冷轧磁过滤产物,考察剂油比、萃取温度、萃取时间对冷轧油回收率的影响,通过中心组合实验设计及响应面分析法优化萃取分离工艺。结果表明,冷轧油回收率的影响因素从大到小依次是剂油比、萃取温度、萃取时间。在优化的工艺条件:剂油质量比5∶1,温度67℃,时间28.0min时,冷轧油的回收率为74.52%,与理论值的误差为0.30%。回收冷轧油性质变化小,有回用的可行性;回收铁粉为极细粉,用途广泛。     

Foam Fractionation of Protein with the Presence of Antifoam Agent

Foam fractionation is a promising technology for protein concentration or purification. However, the presence of an antifoam agent in fermentation broth restricted direct application of the technology. A preliminary approach of the surfactant-assisted foam process was conducted with a simulated system consisting of targeted protein bovine serum albumin (BSA), and a mixed antifoam agent (AF520, silicon oil/PGE mixture). The effects of all three classes of surfactants (anionic SDBS, cationic CTAB, and non-ionic Tween-20) on BSA foam fractionation were examined respectively. Also, the influences of solution pH, PGE, BSA, and NaCl were taken into account. The results revealed that all three classes of surfactants could stabilize foam film, so that the foam process could be operated, while the ionic surfactant exhibited excellent performance on condition that it was allowed to firmly interact with BSA to form a more hydrophobic complex, especially for cationic CTAB. When solution pH was adjusted to 7.5 and CTAB was 20 mg · mL^?1, 90% of BSA could be extracted from a previous non-foaming system containing 100 mg · mL^?1 BSA and 4 mg · mL^?1 AFA, and the enrichment reached 7.42. A higher enrichment of BSA could be obtained with increasing addition of AFA but at the expense of the recovery. On the contrary, increasing BSA concentration gave rise to an opposite performance. The experiments also showed that the foam stability of the system was substantially enhanced by NaCl, significantly lowering the enrichment.     

消泡剂共存体系中泡沫分离蛋白质

在以牛血清白蛋白(BSA)为目标蛋白、聚环氧丙烷环氧乙烷甘油醚(PGE)为消泡剂的模拟体系中,考察了表面活性剂种类(非离子型Tween-20和离子型SDBS)、浓度、溶液pH及操作参数(气体流量、初始液池高度)对BSA分离效率的影响. 结果表明,2种活性剂均能改善模拟体系的泡沫性能,使泡沫分离. 后者作用更强并能促进BSA的吸附,因DBS-通过静电作用与带相反电荷的BSA结合形成疏水性更强的BSA-DBS复合物. pH通过影响BSA的电荷分布而影响其与SDBS的结合,进而影响对BSA的吸附,初始BSA浓度0.1 g/L, PGE 4 mg/L, SDBS 50 mg/L, pH为3.4时,约66%蛋白质浓缩在泡沫液中,富集比为5.34. 增加气速或初始液池高度可得到较高收率,但富集比减小.     

Fractionation of Nanocellulose by Foam Filter

The foam fractionation method was applied for nanocellulose. Experiments were carried out with enzymatically pretreated nano-fibrillated cellulose (NFC) from softwood, as well as commercial products. Narrow channels (plateaus) between bubbles prevent the flow of coarse particles along the water, so that foam acts like a filter. The advantage of the method is no risk of clogging, which could be a big problem for conventional filters or screens. Mean particle size (effective size by means of dynamic light scattering measurement) was reduced by foam fractionation, and the reduction range depended on the cellulose grade and the type of surfactant. The yield turned out to be low, probably because of particle aggregation due to the interaction with surfactant.     

Protein Removal from Whey Waste by Foam Fractionation in a Batch Process

The work investigates the separation of proteins from whey waste collected from a local confectionery by the foam fractionation technique in batch mode. The purpose of this work was to evaluate performance criteria of protein separation. The effects of pH, the concentration of initial feed solution, the nitrogen flow rate, the % gas hold up, the bubble diameter, the breaking time of foam, and the optimization of the protein–surfactant ratio (1.5:1) were investigated in detail. Maximum enrichment ratio (48.189), %Rp (96.378) were observed at a gas flow rate of 330 ml/min and pH 5 that is closest to isoelectric point of observed proteins (Bovine serum albumin, β-Lactoglobulin, α-lactalbumin).     

泡沫分离过程中泡沫层总高度对持液率的影响

以乳链菌肽发酵液为模拟体系,研究了泡沫分离过程中泡沫层总高度对泡沫塔出口持液率εout以及泡沫层轴向持液率分布特性的影响.实验发现:在泡沫层形成过程中,εout从一个较低值逐渐升高到一个较高的稳定值;泡沫在塔内泡沫相中的停留时间不是εout的决定性因素,气速对εout的影响很大.同时还发现:随着泡沫层总高度的增加,εout缓慢下降而泡沫层与液层界面处的持液率急剧上升,可以推测出整个轴向持液率特性分布会上移.实验数据表明仅仅用静态泡沫的排液时间代替上升动态泡沫的停留时间的方法来预测εout的一般方法可能得出错误的结果.     

Separation of Tea Saponin by Two-Stage Continuous Foam Fractionation

A technology of two-stage continuous foam fractionation for tea saponin recovery was studied for increasing both the enrichment ratio and the recovery percentage. In the first stage, the effect of air flow rate, the initial pH, the feed flow rate, and the feed position were studied at a temperature of 60°C. The results showed that when the conditions of the first stage were at a temperature of 60°C, air flow rate 150 mL/min, pH 5.3, feed flow rate 1.92 mL/min, and feed position at the interface between the liquid phase and the foam phase, the enrichment ratio, and the recovery percentage of tea saponin were 4.02 and 56.4%, respectively, and the effluent solution was added to the second stage as the initial solution. When the conditions of the second stage were at a temperature of 30°C and an air flow rate of 300 mL/min, the recovery percentage of tea saponin reached 47.6%, and the foamate was added to the first stage as feed solution. The total recovery percentage of tea saponin reached 86.3% by the two-stage continuous foam fractionation.     

倾斜泡沫相的角度及长度对泡沫分离十六烷基三甲基溴化铵的影响

为了强化泡沫相排液,采用倾斜泡沫相分离塔,以传统垂直泡沫相分离塔为对照塔,以表面活性剂十六烷基三甲基溴化铵(CTAB)为体系,研究倾斜泡沫相倾斜角度和长度对富集比和回收率的影响。结果表明,倾斜角度和倾斜泡沫相长度对泡沫分离效率有显著影响。富集比随倾斜角度的增大先升高后降低,在倾斜角度为40°时达到最大值,回收率先降低后升高,在40°时达到最小值。随着倾斜泡沫相长度的增加,富集比的增加率和回收率的降低率都趋于平缓,确定倾斜泡沫相长度为650 mm。在最佳倾斜角度和倾斜泡沫相长度,装液量为250 mL、初始浓度为0.07 g·L-1、气体流量为200 mL·min-1时,倾斜泡沫相分离塔的富集比为16.7,是对照垂直泡沫相分离塔的1.8倍。     

Span-20和Tween-80对发酵液中Nisin泡沫分离的影响

研究了微量非离子表面活性剂Tween-80和Span-20对发酵液中乳链菌肽(Nisin)泡沫分离的影响. 结果表明,发酵液泡沫分离时泡沫层轴向气泡直径、连续通气过程的泡沫层高度、泡沫层平均持气量等均因添加活性剂而明显变化. 不同体系气泡大小为,含0.2 g/L Span-20发酵液>含0.5 g/L Span-20发酵液>发酵液>含0.2 g/L Tween-80发酵液>含0.5 g/L Tween-80发酵液;Tween-80的加入破坏了气泡表面的网状结构,因而泡沫层持气量较高;连续通气时,2种表面活性剂都会引起泡沫层高度降低,但Tween-80会增加泡沫层的稳定性. 当Tween-80浓度达0.5 g/L时,Nisin的收率大幅度提高,原因是分离过程中Nisin失活率减少.     

Purification and Concentration of the Total Saikosaponins Extracted from Radix Bupleuri using Foam Fractionation

The purpose of this study was to investigate the use of foam fractionation to recover saikosaponins. First, the solvent extraction method was applied for the extraction of saikosaponins from radix bupleuri using ethanol or deionized water. Then, the foam fractionation technique in batch mode was used for the recovery of the total saikosaponins from the extract. The effects of initial concentration, air flow rate, liquid loading volume, pH, and operating time on the process performance were investigated. The recovery percentage 77.2% and an enrichment ratio 3.68 of total saikosaponins with one-stage separation were obtained under the optimal conditions of initial saikosaponin concentration 0.18 mg/mL, air flow rate 50 mL/min, liquid loading volume 200 mL, pH 5.5, and operating time of 2 h. A two-stage foam fractionation technology was also designed, which was effective for improving both the recovery percentage and enrichment ratio simultaneously.     

Intensified Effect of Reduced Pressure on the Foam Fractionation Process of Bovine Serum Albumin

A novel method to intensify the foam fractionation process by operating the column under reduced pressure was reported in this paper. It was found that a poorer foam stability, a bigger mean bubble size and a wider bubble size distribution in the foam layer, a less upward liquid flux and volumetric liquid fraction at the top of the foam layer, and a higher enrichment ratio but a lower mass recovery of the foam fractionation process were obtained under reduced pressures compared to the ones under atmospheric pressure. The most important effect of the reduced pressure on the foam layer during the foam fractionation process is the encouraged bubble coalescence process which was exhibited by those unusual foam properties discussed above. The limitations of this new method were also discussed.