共查询到20条相似文献,搜索用时 234 毫秒
1.
膜法酵母提取海藻糖应用初探 总被引:4,自引:0,他引:4
采用超滤 纳滤技术对活性干酵母溶液中的海藻糖进行提取研究 ,结果表明 :MWCO为 5 0 0 0的卷式超滤膜可截留约 98%以上的蛋白质 ,起到纳滤预处理的作用 ;MWCO为 30 0的卷式纳滤膜对超滤液进行纳滤预浓缩和渗滤操作 ,发现浓缩过程通量随压力的增加而增加 ,随浓缩时间的延长而迅速下降 ,海藻糖截留率变化不大 ;渗滤过程表明渗透通量随渗滤时间的延长而略有增加 ,海藻糖截留率变化不大。经过超滤 纳滤处理 ,海藻糖提取率达 85 %以上 ,纯度 99.4 % ,优于传统乙醇提取方法 相似文献
2.
采用超滤、纳滤操作对酵母抽提物进行处理,结果表明:操作压力、操作时间及料液体积流量对超滤有很大影响,所选MWCO为5000的膜件可去除96%以上的大分子蛋白质,起到纳滤预处理作用.采用MWCO为300的纳滤膜对超滤液进行浓缩纯化,海藻糖总提取率高达85.6%,大大高于传统方法.操作条件如进料压力、浓缩倍数及操作方式对纳滤过程均有很大影响。 相似文献
3.
在前期对壳聚糖酶解液进行超滤分离的基础上,进一步深入研究了用相对截留分子质量为500Da的卷式纳滤膜对超滤液进行纳滤分离技术条件。以膜通量、氨基葡萄糖脱除率、电导率和pH值为评价指标,研究了操作压力、操作温度、滤液pH值等工艺参数对壳聚糖酶解液纳滤分离纯化效果的影响。最终确定纳滤分离的最佳操作参数为:操作压力0.50MPa、操作温度35℃、滤液pH 3.0。对纳滤分离后得到的产品进行分析:氨基葡萄糖含量1.21%、灰分含量0.15%、聚合度为3~6的壳寡糖含量70.25%,产品得率70.12%。 相似文献
4.
5.
6.
7.
8.
研究了膜技术分离纯化朝鲜蓟叶中洋蓟素的工艺过程,在超滤过程中,采用膜通量及洋蓟素浓度为考察指标。结果表明,10万Da分子量规格的膜为最佳选择,具有较大的膜通透性,产品洋蓟素的截留率低(1.79%)。在产品的纳滤过程,考察膜的透水通量、待测溶液纳滤前后的电导率及洋蓟素浓度指标。结果显示,选用合适的纳滤膜(300Da),浓缩效果好,洋蓟素的产品浓度提高到原液的34.9倍,同时浓缩液中电导率只为普通热真空浓缩的1/10左右。研究结果表明,膜分离技术在本实验研究中应用效果显著,适于进一步的推广应用。 相似文献
9.
膜技术分离七叶参皂甙研究 总被引:12,自引:0,他引:12
以七叶参为材料,研究了微滤澄清、超滤除大分子、纳滤分离、纳滤浓缩等膜技术在分离七叶参皂甙的应用效果。结果表明,采用0.2μm微滤膜在40℃条件下微滤经粗滤后的七叶参浸提液,且在微滤滤液达到浸提液重的80%时加入与原料等重的透析水透析残渣可作为微滤澄清的技术参数;选用截留分子量为10000Da的超滤膜能有效去除色素等大分子物质;利用截留分子量为2500Da或3500Da的纳滤膜分离七叶参皂甙,可制得纯度为42%以上的七叶参皂甙产品,且3500Da纳滤膜比2500Da纳滤膜的得率要高,但干粉中皂甙纯度略低;选用500D的纳滤膜在32℃左右、操作压力为1.8MPa的条件下浓缩七叶参皂甙不仅浓缩效率高,而且可进一步提高产品纯度。 相似文献
10.
11.
Achyut Mishra Ram R Panthi Steven L Beckman Khrupa S Vijayaragavan Sanjeev Anand Lloyd E Metzger 《International Journal of Dairy Technology》2023,76(2):364-370
The performance of nanofiltration (NF) as influenced by hydrodynamic cavitation (HC) and filtration temperature during the concentration of milk protein concentrate (MPC) was investigated. Pasteurised skim milk was concentrated using ultrafiltration (UF) to prepare UF retentate (MPC80, 20% total solids, TS), which was then further concentrated using NF at 22°C and 50°C with or without HC treatments until permeate flux declined to 0.1 L/m2/h. Results showed that UF retentate can be concentrated to higher TS (up to 31.5%) at higher filtration temperature or by applying HC, with synergistic effect in combination of both treatments, during NF. 相似文献
12.
Potato starch wastewater contains high-concentration potato proteins which have great potential in the fields of food and health care. Most researches on potato protein recovery by membrane separation technique are focused on flat sheet or tubular ultrafiltration (UF) and reverse osmosis (RO) membranes and lack the further protein purification and the in-depth discussions on the fouling behavior. In this laboratory-scale study, potato proteins were recovered and purified from the simulated potato starch wastewater by the self-made hollow fiber (HF) UF and nanofiltration (NF) separation membrane integrated process. 85.62% potato proteins with high molecular weight in the potato starch wastewater could be retained by UF membrane and 92.1% potato proteins with low molecular weight were rejected by NF membrane. The concentrated solution after UF and NF filtration was desalinated and purified by diluting the solution eight times and filtering the diluted solution with UF membrane. Both types of HF membranes, UF and NF, suffered the inevitable membrane fouling. After the traditional physical washing and chemical cleaning, water flux of UF and NF membranes can be effectively recovered. The corresponding recovery rates of UF and NF membranes can reach 93.5% and 84.7%, respectively. The hollow fiber UF-NF separation membrane integrated process was proved to be a promising technique of high-purity potato protein recovery from potato starch wastewater. 相似文献
13.
高效节能的膜集成技术已开始应用于食品和药用植物中有效成分的分离提取。文中针对灵芝提取液的特性,依据微孔过滤(MF)、超滤(UF)、纳滤(NF)各种膜对特定物质的选择分离性能,设计了新型膜集成工艺,即筛网和滤纸粗过滤除杂和MF净化处理,进而用不同切割分子质量(MWCO)膜进行两级UF、最后用NF净化浓缩灵芝水提液的创新技术。在操作压力≤0.20 MPa和15 m/s的高膜面流速,1.0 mL/(cm~2·h)恒通量模式下,灵芝水提液先后经MWCO分别为5万的聚丙烯腈(PAN)膜和1万的醋酸纤维素(CA)膜进行UF批次处理。UF渗透液再经截留分子质量为1 50~300的DK(标准)型聚酰胺(PA)膜进行纳滤浓缩,浓缩倍数达6倍时,渗透通量在0.92~0.33 mL/(cm~2·h),纳滤渗透液的色度在浓缩过程稳定在70~80,有效成分截留率高。 相似文献
14.
本实验研究了膜技术分离纯化绿原酸提取液的过程。首先,以透水通量为指标,比较了两种微滤膜MF1和MF2、两种超滤膜UF1和UF2及两种纳滤膜NF1和NF2对绿原酸提取液的过滤特性。结果表明,MF2膜的通量可高达167.7kg/h,UF2膜的通量可达148.8kg/h和NF2膜的通量可达109.8kg/h,分别明显高于MF1(103.6kg/h)、UF1(48.0kg/h)和NF1(45.6kg/h);其次,研究了浓缩液的水洗对绿原酸截留率的影响。结果表明,经一次水洗后,MF2膜的截留率可由12.5%降低到3.4%,UF2膜的截留率可由15%降低到8%;最后,分析了膜分离过程中各物料的成分。结果表明,纳滤浓缩液含绿原酸为17964mg/L,比原提取液提高了24.8倍,绿原酸的纯度由2.8%上升到27%。 相似文献
15.
《Journal of food engineering》2008,84(4):590-595
Xanthophylls such as lutein and zeaxanthin are naturally occurring yellow–orange oxygenated pigments of the carotenoid family. They can be extracted from plant materials with organic solvents such as ethanol or hexane. The objective of this research was to develop methods for concentrating and purifying xanthophylls extracted from corn using membrane technology. Ultrafiltration (UF) was used to separate ethanol-soluble protein (zein) and other large solutes from the extract. The xanthophyll-containing stream was concentrated and separated from the solvent using nanofiltration (NF). Ethanol can be recycled back to the process. This study focused on screening commercially available and prototype polymeric UF and NF membranes for the flux and rejection of model lutein solutions and aqueous ethanol extracts of whole ground corn. 相似文献
16.
Shon HK Vigneswaran S Aim RB Ngo HH Kim IS Cho J 《Environmental science & technology》2005,39(10):3864-3871
Membrane fouling is a critical limitation on the application of membranes to wastewater reuse. This work aims to understand the fouling phenomenon which occurs in ultrafiltration (UF; 17500 molecular weight cutoff (MWCO)) and nanofiltration (NF; 250 MWCO) membranes, with and without pretreatment. For this purpose, the molecular weight (MW) distribution of the organics has been used as a parameter to characterize the influent, the permeate, and the foulant on the membrane surface. The variation of foulant concentration on the membrane due to pretreatment of the influent by flocculation and/or adsorption was investigated in detail. With the UF membrane, the peak of the MW distribution of organics in the permeate depended on the pretreatment; for example, the weight-averaged MW (Mw) of 675 without pretreatment shifted down to 314 with pretreatment. In the case of the NF membrane, the Mw of organics in the permeate was 478 (without pretreatment) and 310 (with flocculation followed by adsorption). The Mw of the organics in the foulant on the membrane surface was 513 (UF) and 192 (NF) without pretreatment and 351 (UF) and 183 (NF) after pretreatment with flocculation followed by adsorption, respectively. Without the pretreatment, the foulant concentration was higher on both membranes. The difference was more significant on the UF membrane than on the NF membrane. For both membranes, the flocculation-and-then-adsorption pretreatment proved very effective. 相似文献
17.
Mushroom blanch water was concentrated by ultrafiltration (UF) and reverse osmosis (RO). UF prefiltration was essential in preventing severe fouling during the RO process. When the UF blanch water permeate was processed by RO, linear relationships between pressure and flux were observed at all concentrations tested. The blanch water was concentrated by UF/RO from 2% to 13% total solids at 60°C and 120 KPa/5000 KPa operating pressures with flux higher than 15 L/m2 hr. Maximum concentration obtained was approximately 20% total solids with 90% recovery of the nonvolatiles. Recoveries of some major volatiles were above 50%. Panelists could not differentiate the original from the reconstituted blanch waters in sensory evaluations. 相似文献
18.
Pectate oligosaccharides were separated from enzymatically hydrolyzed pectate by using ultrafiltration (UF) and nanofiltration (NF) membranes. The UF treatment was performed at a transmembrane pressure of 0.15 MPa and flow velocity of 0.6 m.s(-1), and nonhydrolyzed pectate was removed almost completely. The NF treatment was carried out at a transmembrane pressure of 0.5 MPa and flow velocity of 0.6 m.s(-1), and large amounts of monogalacturonic acid and sucrose, the contaminants included in the UF permeate were separated. Pectate oligosaccharides obtained by the diafiltration treatment of the NF concentrate were mainly composed of di- to pentasaccharides and exhibited root-growth-promoting activity in lettuce (approximately 1.8-fold) compared with the control. In particular, penta-, tetra-, and disaccharides were found to have strong activity. 相似文献
19.
A membrane process offers several advantages over the conventional method of oil refining. Conceptually, membranes could be used in almost all stages of processing. In the present review, various attempts made by the researchers towards degumming, dewaxing, deacidifying, and decolorizing edible oils using membrane technology with and without using solvents have been discussed. Attempts made with UF and nonporous membranes have demonstrated the ability of these membranes to separate phospholipids from undiluted and hexane-diluted oils and a high oil flux was obtained with UF membranes in hexane-diluted oils. MF membranes were very effective for dewaxing undiluted oils while UF membranes were effective in dewaxing hexane-diluted oils without a precooling step. Deacidification was successful only with either addition of an alkali followed by membrane filtration or by following an indirect route of selective solvent extraction of FFA followed by membrane separation. Consistent color reduction in terms of pigments (chlorophyll and xanthophylls) and other instrumental measurements (Lovibond and visible spectra) could be achieved only with nonporous membranes. Interestingly, these membranes did not have selectivity for alpha-and beta-carotenes. UF membranes are best suited for degumming and dewaxing applications, while nonporous membranes appear to be a better choice for achieving simultaneous degumming, dewaxing, and decolorization of oils. Hexane-dilution improved the oil flux of nonporous membranes by one order of magnitude, but further improvement is desirable for industrial adoption. 相似文献
20.
采用超滤/纳滤技术对肠衣废水进行深度处理,研究操作压力和处理时间对膜性能的影响。结果表明,适宜的超滤压力为0.25MPa,运行1h后,肠衣废水的COD(chemical oxy-gen demand)、BOD(biochemical oxygen demand)的平均去除率分别大于60%和35%,平均膜通量大于580L/(m2.h);适宜的纳滤压力为1.4~1.6MPa,连续运行3h后,肠衣废水COD、BOD和氯离子的平均去除率分别大于70%、90%和98%,平均膜通量大于60L/(m2.h);最终出水的水质可以达到中水回用的要求。 相似文献