陶瓷膜微滤技术在牛乳除菌中的应用

对陶瓷梯度膜用于牛乳微滤除菌的效果及其可行参数进行了研究.结果表明,0.8与1.2 μm孔径梯度膜对细菌高效截流,截留率达到了99.5%以上.0.8μm孔径梯度膜在温度为50℃、浓缩20倍的条件下,蛋白截流率为10%,膜通量为300L/(m2·h).     

陶瓷膜微滤技术在纤维素酶除菌工艺中的应用

陶瓷膜微滤技术在纤维素酶后提取的除茵工艺中,大大提高了去茵效果,降低了劳动强度,节约经济成本,改善劳动环境,缩短生产周期.     

陶瓷膜在哈密瓜汁微滤除菌工艺中的应用研究

哈密瓜汁对热敏感,为了减少因热处理导致的营养成分和风味物质的损失,采用无机陶瓷膜对哈密瓜汁进行微滤除菌。通过研究三种孔径膜的膜通量、微滤前后哈密瓜汁营养成分的变化及除菌效果,选择最适的膜孔径,并在此基础上选择最适的操作压力和进料温度,从而确定最佳的微滤除菌工艺参数。结果表明:最佳的工艺参数为膜孔径0.2μm,操作压力0.2MPa,进料温度25℃。在此条件下处理的哈密瓜汁透光度可达98.8%,浊度为2.61NTU,菌落总数为13CFU.mL-1,其中大肠菌群、霉菌、酵母菌均未检出。      

陶瓷膜微滤生物柴油的研究

用孔径0.6、0.2、0.1μm陶瓷膜在进口压力0.26MPa、出口压力0.06MPa、温度60℃下微滤粗生物柴油除去其中的皂和游离甘油。结果表明,0.1μm的陶瓷膜滤过液中K、Na、Ca、Mg和游离甘油含量达到欧盟生物柴油标准(EN14214)。用孔径为0.1μm陶瓷膜微滤生物柴油,当浓缩比为4∶1时,膜通量为300L/(m2.h),得到总滤过液中的K、Na、Ca、Mg的含量分别为1.40、1.78、0.81、0.20mg/kg,游离甘油含量为0.0108%。     

陶瓷膜微滤技术生产ESL牛乳的应用研究

对Membralox GP1．4μm陶瓷膜在脱脂牛奶除菌过程中的应用进行了实验研究。在原料温度50℃、浓缩倍数(VCR)为20的条件下，连续过滤6．5h，过膜压力(TMP)和流量基本保持恒定，细菌分离效率大于5；确定了膜的操作条件和再生方式，结果表明，膜过滤的牛奶采用不同的温度杀菌后无菌包装，货架期显著延长。应用膜过滤技术可生产延长货架期(ESL)牛奶。     

陶瓷膜在卤制品加工废弃液微滤中的应用

探讨了陶瓷膜用于卤制加工废弃液微滤的工艺条件。研究不同预处理方法、膜孔径、操作温度、操作压力等因素对膜通量的影响,并通过正交实验确定微滤的最佳工艺参数为:预处理网筛300目、陶瓷膜孔径0.22μm、操作温度50℃、操作压力0.075 MPa,通过质量分数0.75%NaOH和0.5%柠檬酸复合清洗后,陶瓷膜的通量恢复率可达到94.1%。     

陶瓷膜微滤制备食用级浓缩磷脂的研究

用无机陶瓷膜微滤饲料级大豆磷脂-正己烷混合溶液制备出了杂质含量少、透明程度高的食用级浓缩磷脂。研究了膜孔径、压力、料溶比、温度与膜通量的关系以及不同膜孔径、溶料比、温度对磷脂丙酮不溶物含量、正己烷不溶物含量的影响。实验表明,在40℃,0.20MPa压力下,饲料级浓缩磷脂与正己烷质量比为1∶3的混合溶液用1.2μm孔径陶瓷膜微滤,初始膜通量为110L/(m2·h),微滤后产品中丙酮不溶物含量和正己烷不溶物含量分别为60.20%和0.0082%,符合食用级浓缩磷脂的要求。     

乳酸杆菌无机陶瓷膜微滤浓缩条件的研究

采用无机陶瓷膜管微滤技术浓缩乳酸杆菌发酵液。实验中比较了不同膜管孔径、膜管面积、操作压力等对乳酸杆菌发酵液浓缩效果的影响。结果表明,选择无机陶瓷膜管孔径为0.1μm,膜面积为0.24 m2,操作压力为0.15 MPa,可得到体积浓缩5.6倍,活菌死亡比0.2,截留率达96%的乳酸杆菌浓缩液。无机陶瓷膜可用于乳酸杆菌发酵液的浓缩处理。     

颇尔Oenoflow^TM XL—E错流微滤系统

OenoflowXL-E系统组件 ——葡萄酒、饮料、果汁、糖浆、香精过滤的理想选择 OenoflowXL—E系统是全自动的组装式系统，可以由一个或两个错流过滤膜柱组合而成。304不锈钢管复式接头、膜、泵和其他器具安装在一个可移动的平台上。     

脱脂牛乳陶瓷膜过滤除菌工艺研究

以新鲜牛乳为主要原料,结合膜过滤设备的特点,采用L<'9>(3<'4>)正交试验方法,研究脱脂乳利用陶瓷膜过滤工艺除菌时不同的跨膜压力、错流速率、浓缩系数和脱脂乳干物质含量对膜通量、除菌率、蛋白截留率的影响和膜使用时清洗时间间隔.结果表明,脱脂牛乳利用陶瓷膜过滤除菌的最佳工艺条件:跨膜压力0.15 MPa,错流速率6 m/s,浓缩系数0.85,脱脂牛乳干物质含量8%,截留侧膜前后压降为0.24 MPa,除菌率可达到99.86%.     

Determination of the efficiency of removal of whey protein from sweet whey with ceramic microfiltration membranes

Our research objective was to measure percent removal of whey protein from separated sweet whey using 0.1-µm uniform transmembrane pressure ceramic microfiltration (MF) membranes in a sequential batch 3-stage, 3× process at 50°C. Cheddar cheese whey was centrifugally separated to remove fat at 72°C and pasteurized (72°C for 15 s), cooled to 4°C, and held overnight. Separated whey (375 kg) was heated to 50°C with a plate heat exchanger and microfiltered using a pilot-scale ceramic 0.1-µm uniform transmembrane pressure MF system in bleed-and-feed mode at 50°C in a sequential batch 3-stage (2 diafiltration stages) process to produce a 3× MF retentate and MF permeate. Feed, retentate, and permeate samples were analyzed for total nitrogen, noncasein nitrogen, and nonprotein nitrogen using the Kjeldahl method. Sodium dodecyl sulfate-PAGE analysis was also performed on the whey feeds, retentates, and permeates from each stage. A flux of 54 kg/m² per hour was achieved with 0.1-µm ceramic uniform transmembrane pressure microfiltration membranes at 50°C. About 85% of the total nitrogen in the whey feed passed though the membrane into the permeate. No passage of lactoferrin from the sweet whey feed of the MF into the MF permeate was detected. There was some passage of IgG, bovine serum albumen, glycomacropeptide, and casein proteolysis products into the permeate. β-Lactoglobulin was in higher concentration in the retentate than the permeate, indicating that it was partially blocked from passage through the ceramic MF membrane.     

Process efficiency of casein separation from milk using polymeric spiral-wound microfiltration membranes

Microfiltration is largely used to separate casein micelles from milk serum proteins (SP) to produce a casein-enriched retentate for cheese making and a permeate enriched in native SP. Skim milk microfiltration is typically performed with ceramic membranes and little information is available about the efficiency of spiral-wound (SW) membranes. We determined the effect of SW membrane pore size (0.1 and 0.2 µm) on milk protein separation in total recirculation mode with a transmembrane pressure gradient to evaluate the separation efficiency of milk proteins and energy consumption after repeated concentration and diafiltration (DF). Results obtained in total recirculation mode demonstrated that pore size diameter had no effect on the permeate flux, but a drastic loss of casein was observed in permeate for the 0.2-µm SW membrane. Concentration-DF experiments (concentration factor of 3.0× with 2 sequential DF) were performed with the optimal 0.1-µm SW membrane. We compared these results to previous data we generated with the 0.1-µm graded permeability (GP) membrane. Whereas casein rejection was similar for both membranes, SP rejection was higher for the 0.1-µm SW membrane (rejection coefficient of 0.75 to 0.79 for the 0.1-µm SW membrane versus 0.46 to 0.49 for the GP membrane). The 0.1-µm SW membrane consumed less energy (0.015–0.024 kWh/kg of permeate collected) than the GP membrane (0.077–0.143 kWh/kg of permeate collected). A techno-economic evaluation led us to conclude that the 0.1-µm SW membranes may represent a better option to concentrate casein for cheese milk; however, the GP membrane has greater permeability and its longer lifetime (about 10 yr) potentially makes it an interesting option.     

Mathematical modeling of crossflow microfiltration of diluted malt extract suspension by tubular ceramic membranes

The practical application of microfiltration in brewing industry is hindered by severe membrane fouling and subsequent permeate flux decline. A theoretical and experimental study on the effect of operating parameters, which influence the crossflow microfiltration of beer and beer quality was performed. A mathematical model is developed to better understanding of the fouling layer characteristics. The experiments were conducted for different ranges of pressures, temperatures and shear rates. An optimum transmembrane pressure of 1.1 bar is suggested to maximize both the steady state and average permeate fluxes. The results of numerical simulation were in a good accordance with the experimental data.     

Gentle milk fat separation using silicon carbide ceramic membranes

Due to their high hydrophilicity, ceramic silicon carbide (SiC) membranes are suitable for fat separation from raw milk, as alternative to centrifugation. The filtration performance during separation of fat globules (MFGs) from raw milk showed 95% fat separation at 15 °C, 93% at 25 °C, 88% at 35 °C and 91% at 50 °C, while permeating skimmed milk with a fat concentration ranging from 0.11 ± 0.03 to 0.34 ± 0.23% (w/w). The filtration time ranged from 12 to 106 min, respectively for 50 and 15 °C. Fouling of the membranes was investigated using scanning electron microscopy and elemental composition by energy dispersive X-ray. The SiC membranes showed a defect-free morphology, excellent water permeability and no irreversible fouling after the filtration process. Separation at 50 °C showed a higher distribution of larger MFGs in the permeate due to increased flexibility of the MFGs.Industrial relevanceMicrofiltration has previously been proposed to be a gentler separation method compared to traditional centrifugation. In this study, for the first time was demonstrated that highly hydrophilic ceramic silicon carbide (SiC) membranes are an efficient process for separation of fat from raw milk. The effect of filtration temperature on filtration performance and properties of the resulting streams provided new insights for industrial application of this process.     

Identification of optimal membrane morphological parameters during microfiltration of mosambi juice using low cost ceramic membranes

In this work, experimental investigations were carried out for the identification of optimal membrane morphological parameters (pore size distribution, average pore size and porosity) during microfiltration (MF) of mosambi juice using low cost ceramic membranes. Four different low cost ceramic membranes with different pore diameters (d_m) and porosities (?) were subjected to MF studies to evaluate the effect of d_m and ? on permeation characteristics (permeate flux and juice quality) of centrifuged mosambi juice (CJ) and enzyme treated centrifuged mosambi juice (ETCJ). Subsequently, a convenient factor namely effective permeable area factor (?_md_m²) was evaluated to provide greater insights in the fouling phenomena. Various physio-chemical properties such as colour, clarity, pH, citric acid content, density, total soluble solid (TSS) and alcohol insoluble solids (AIS) were measured for both feed and permeate juice samples to evaluate the effect of ?_md_m² on juice quality. Typical permeate fluxes were observed to vary from 5.78 × 10⁻⁶ to 13.45 × 10⁻⁶ m³/m² s for CJ and 14.07 × 10⁻⁶ to 60.64 × 10⁻⁶ m³/m² s for ETCJ at 82.7 kPa (ΔP) for different membranes whose ?_md_m² varied from 0.249 to 0.783 μm². Among different membrane pore blocking models, flux decline by cake filtration was found to be the best fitted model. The cake filtration model constant (k_c) was found to vary with ΔP and ?_md_m² and was empirically correlated. Phenomenological models were proposed to illustrate the dependency of total hydraulic resistance of membrane on ?_md_m², ΔP and time (t). Based on experimental as well as theoretical investigations, membranes with ?_md_m² up to 0.443 μm² for CJ and 0.294 μm² for ETCJ and a ΔP of 82.7 kPa were recommended for MF of mosambi juice.     

甘蔗混合汁粒径分布及陶瓷微滤膜过滤阻力研究

建立了甘蔗混合汁中颗粒粒径分布测定和分析方法;研究了0．1μm、0．2μm和0．45μm陶瓷微滤膜分析甘蔗混合汁时的阻力分布,探讨了不同膜元件主要阻力形式,确定了阻力分析方法。结果表明：致密性膜的制造精度越高,过滤料液时总阻力相对较小,孔隙率高的膜元件堵塞阻力随膜孔径减小而降低,利于膜通量的恢复和延长使用时间。     

Processing of extended shelf life milk using microfiltration

Extended shelf life (ESL) milk was processed with integrated microfiltration (pore size 1.4 µm). The germ-enriched retentate was not used for the final whole milk. Microfiltration led only to a negligible change in the content of the main components of the ESL product compared with the source milk. The total protein was only slightly decreased (0.02–0.03%) and the ratio of the protein fractions was unchanged within the measurement accuracy. The furosine content of the isolated fat globuline membrane fraction could be used as a diagnostic to prove cream had been subjected to high-temperature treatment. The shelf life of the ESL milk was distinctly prolonged compared to HTST-pasteurized milk.