膜分离技术在饮料工业中的应用

膜是一种具有特殊选择性分离功能的无机或高分子材料,它能把流体分隔成不相通的两个部分,使其中的一种或几种物质能透过,而将其他物质分离出来。在饮料工业中,主要应用的膜分离过程包括微滤、超滤、电渗析与反渗透。选择适当的膜分离过程可替代目前饮料等行业中应用的部分鼓式真空过滤、板框压滤、袋式过滤、离子交换、离心分离、溶媒抽提、静电除尘、絮凝/共聚、蒸发、结晶等传统的分离过滤方法。     

膜技术在饮料行业的应用

作为高科技领域的膜分离技术,在开发应用中除了自身的质量、价格外,还与国民经济的发展有着密切的关系。改革开放以来,我国的国民经济得以迅速发展,人民生活水平、文化素质都大大提高,对食品、饮料需求的数量和质量也在不断的增长。人们对饮料品种、品质、营养价值、卫生状况的高标准要求,使得饮料生产厂在激烈的市场竞争中,为了提高饮料的档次,竞相购置膜分离水处理设备。由于膜技术的分离是在常温下无相变进行的一种物理过程,不仅保留了水的生物活性,而且能去除水中的微生物、杂质、悬浮物及金属盐类等物质,是饮料水处理中较为理想的一种方法。近几年来,膜技术在饮料行业越来越受到重视,成为膜技术开发应用的一个主要领域。     

膜分离技术在食品工业中的应用

<正> 概述:膜分离技术(反渗透、超过滤、微孔过滤)是本世纪六十年代初发展起来的新兴化工分离单元。它是以膜两侧的压力差为动力,在常温下对溶质与溶剂进行分离浓缩与纯化。 根据分离物质的差别,膜分离技术大致可分反渗透,超过滤和微孔过滤。反渗透适用于分子量小于500的低分子无机物或有机物水溶液的分离。超过滤适用于大分子(蛋白质、胶体、多糖等)与小分子(无机盐及低分子有机物等)溶液的分离。微孔过滤适用于细菌、微粒等分离。由于分离物质的差别,其分离所需的操作压力,通常反渗透为0.1—10MPa,超过     

渗透蒸发及其在发酵工业中的应用

<正> 物质的分离,一般采用过滤、蒸馏、重结晶、萃取、离心及吸附等方法。近20年来,随着对膜现象研究的不断深入和膜科学的飞速发展,一门崭新的边缘学科—膜分离科学与技术应运而生,并日益显示出其重要性。 作为一种有效的分离手段,膜分离已广泛应用于食品与发酵工业、乳品工业、制药工业、冶金工业、纺织工业以及环境保护等各个领域。 其中,渗透蒸发过程由于其特殊性而独具其特殊用途。作为一种精密分离过程,近年来获得了广泛而深入的研究,具有广     

膜分离技术及其在食品工业中的应用

一、引言膜分离技术或膜过滤是利用具有渗透性和半渗透性的膜将溶液中的组分加以分离的方法。它与通常筛分或过滤的区别在于,膜分离技术能分离溶液中的溶剂或某些溶质(同样也可用于处理胶态物料和悬浮固体),一般筛分或过滤仅能分离不溶性的固体,最小分离颗粒的极限为1μ左右,而膜分离技术则可在微米级、亚微米级,分子级和离子     

膜分离技术在食醋澄清中的应用

膜分离技术具有简单、高效、低能耗等优点,以其分离过程无相变、无化学变化并适用于多种物料分离的特点,而成为了一种新兴的分离技术。文中系统概述了膜在食醋生产过程中膜的选取、过滤过程条件优化、防止膜污染以及膜清洗技术的研究进展。分析了制约我国膜分离技术应用于食醋工业化生产的关键问题并对其应用前景进行了展望。     

功能性高分子膜材料的现状及今后的发展

<正> 膜分离技术简介(一)膜分离机理功能性高分子膜因具有透析、超滤和反渗透等功能,因而可以把二组分(或以上)的混合流体分离开来。膜分离机理与传统的过滤机理不同,过滤是藉助筛分式附着作     

膜分离技术和酿酒工业

一膜分离技术概况物质的分离方法多种多样,由于能源问题的突出,许多国家都在为探索低能源的分离技术,进行了大量艰巨的开拓性工作,膜分离技术就是其中突出的一项。过滤分离是一种最古老的方法,从历史资料来看,我国是最早用文字记载多孔介质过滤的国家;国外于公元前6世纪基太迦人也描述了对酒的过滤,膜过滤分离技术是在传统方法的基础上发展起来的一门新兴学科。由于现代工业的需要,对过滤分离等级要求     

聚砜酰胺（PSA）外压管式超滤膜在食品工业中的应用

聚砜酰胺（ＰＳＡ）外压管式超滤膜在食品工业中的应用余实江西省商业科学技术研究所３３００４６膜分离技术是本世纪六十年代初以来,迅速发展起来的广泛用于物质分离、浓缩和提纯的一种高新应用技术。由于膜分离过程中,物质不发生相态转变,分离系数较大,操作温度在室...     

膜分离技术在岩藻寡糖分离纯化中的应用

膜分离技术是一种先进的选择性分离技术,这门技术出现在20世纪初,并在20世纪60年代后迅速崛起。膜分离技术由于兼有分离、浓缩、纯化和精制的功能,又有高效、节能、环保、分子级过滤及过滤过程简单、易于控制等特征具有自身独特的优势,随着工业的不断发展,膜分离技术已经广泛应用在工业水处理当中。现已对膜分离技术的各个领域开展了研究工作,并推广于制造业及工业应用。本文介绍了膜分离技术用于一种生物大分子的分离纯化应用,以马尾藻为原料,采用传统水体醇沉的方法制备出多糖,经过一些预处理操作,并配合以膜技术的综合设置为分离提纯的方法,使岩藻寡糖的纯度得到很大的提高,具体表现为除盐,除砷,除杂蛋白等。经过试验验证:采用微滤、超滤、纳滤三者结合的综合膜处理操作之后,能使岩藻寡糖的纯度有显著提高。     

Utilisation of salty whey ultrafiltration permeate with electrodialysis

Salty whey is a waste by-product that incurs increasingly high disposal costs for the dairy industry. This study investigated electrodialysis of the ultrafiltration permeate of salty whey as either a concentrate for the treatment of sweet whey or as a source of lactose and salt. The type of concentrate (0.1 m NaCl or salty whey permeate) did not affect the rate of sweet whey demineralisation or the energy consumed per tonne of whey, but less sodium and more divalent cations were removed when salty whey permeate was used as the concentrate. Salty whey permeate could be effectively demineralised using either 0.1 m NaCl or a second stream of salty whey permeate as the concentrate. The concentrate purity could be enhanced using monovalent selective membranes without increasing the energy consumption of the process (3.2 ± 0.3 kWh per kg of NaCl removed from the diluate at 15 V).     

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.     

An investigation of the fractionation of whey proteins by two microfiltration membranes with nominal pore size of 0.1 μm

There is growing interest in the fractionation of whey proteins because of the specific properties of individual whey proteins. The objective of this work was to assess the efficiency of two membranes to obtain two fractions, one rich in β‐lactoglobulin (β‐Lg) and the other rich in α‐lactalbumin (α‐La) from a whey‐protein concentrate using microfiltration (MF). Two MF membranes were tested for the fractionation: a flat‐sheet membrane VCWP and a spiral membrane MF‐7002, both with nominal pore sizes of 0.1 μm. The VCWP retained 78% of the proteins in solution, and this membrane was shown to be permeable to both proteins, β‐Lg and α‐La. The retention of protein by MF‐7002 was 65%, and there was a partial retention of lactose. The permeate collected in the MF‐7002 in the concentration stage was over 50%α‐La; although this was present in lower concentrations, it was passed preferentially to the permeate. The results indicated that some aggregation of the proteins may have occurred under the experimental conditions because there was only a partial separation of the proteins under study.     

Composition of Some Organic and Inorganic Compounds in Reverse Osmosis-Concentrated Citrus Juices

Orange, grapefruit and lemon juices were concentrated over twofold in a pilot scale reverse osmosis (RO) process using a commercially available membrane system. Major sugars, acids, vitamin C, aroma volatiles and over 20 minerals were examined in feed, concentrate and permeate streams. Typically, 15–20 aroma compounds were identified in feed juices and concentrates. Compared with less volatile compounds (e.g., ethyl butyrate, limonene), poorer retention during processing was noted for more volatile molecules (methanol, acetaldehyde, ethanol). °Brix of membrane concentrates were orange (25.3°B), grapefruit (25.1°B) and lemon (22.5°B). Vitamin C was rejected efficiently by the membrane. Mineral analyses showed similar elemental contents in feed and concentrate and insignificant concentration in permeate streams.     

Electrodialysis Desalination and Reverse Osmosis Concentration of an Industrial Mussel Cooking Juice: Process Impact on Pollution Reduction and on Aroma Quality

ABSTRACT: An industrial mussel cooking juice was treated by a 3-step process to produce a natural aroma concentrate and a cleaned water stream. The juice was centrifuged before being desalinated by electrodialysis and then concentrated by reverse osmosis. As a result of this combined process, most of the physicochemical properties of the reverse osmosis permeate were reduced below the discharge standards. The concentrate was examined by a trained sensory panel (triangular tests, sensory profiles) and by gas chromatography/mass spectrometry. The sensory profile of the concentrate was shown as slightly different from the unprocessed mussel cooking juice one. Nevertheless, the concentration process preserved the native characteristic aroma of the cooked mussel, of interest to human or pet food industries.     

Selecting ultrafiltration and nanofiltration membranes to concentrate anthocyanins from roselle extract (Hibiscus sabdariffa L.)

Ten nanofiltration flat-sheet membranes and eight tight ultrafiltration membranes with nominal MWCOs ranging from 0.2 to 150 kDa were tested to concentrate anthocyanin extract from roselle. A pilot system was used, which featured a membrane cell with an effective area of 0.0155 m². Permeate fluxes were recorded for transmembrane pressures between 0.5 and 3.0 MPa, while keeping all other operating conditions constant (volumetric reduction ratio 1, 35 °C). Retention values of total soluble solids, acidity and anthocyanins increased with transmembrane pressure. With similar permeate fluxes at average transmembrane pressure, retention of anthocyanins is significantly higher for nanofiltration membranes than for ultrafiltration membranes. A membrane was then selected for an industrial trial on the basis of its flux, retention of compounds of interest and energy consumption per liter of permeate. The trial using a 2.5-m² filtration surface, could concentrate roselle extract from 4 to 25 g total soluble solids per 100 g, with 100% retention of anthocyanins. No significant damages were observed when comparing concentrate quality with the initial roselle extract.     

超滤法浓缩鳀蒸煮液的数学模型

采用切向流超滤技术浓缩鳀鱼蒸煮废弃液中蛋白质,在前期对超滤压力、进样流速、样品pH 值、操作温度等操作条件研究的基础上,建立超滤数学模型,通过实验获得拟合参数。结果表明：模型理论值曲线与实验值曲线拟合良好,各曲线的相关系数均在0.99 左右,且膜通量理论值和实验值之间的误差较小,范围在0.44%～10.00% 之间。在工业化设计和实践中,可以根据该数学模型预测超滤条件的变化对超滤过程的影响,根据该模型选择最佳的操作条件,有效地控制浓差极化和膜污染。     

DYNAMIC TURBULENCE PROMOTION IN REVERSE OSMOSIS PROCESSING OF LIQUID FOODS

SUMMARY– The phenomenon of concentration polarization operates to reduce the efficiency of solvent-solute separation in the processing of foods by reverse osmosis. The viscous nature of most food concentrates aggravates the problem. Disrupting the boundary layer by mechanically inducing turbulence in the fluid stream improves the permeation efficiency. Flux improvement of up to 3-fold is possible with dynamic turbulence promotion involving plastic spheres moving randomly with the orange juice concentrate. Concentrate (and sphere) movement is pulsed alternately from one end of the membrane flow channel to the other. The spheres are confined within the flow channel to avoid the problem of moving them through the recycling pumps. A net movement of concentrate results when the pump volume is greater in one direction than the other. The permeation rate with dynamic turbulence promotion does not drop off significantly with time. The long-term effects of sphere movement on the membrane surface are not known but are believed not to be serious.     

Coupling of pressure-driven membrane technologies for concentrating,purifying and fractionizing betacyanins in cactus pear (Opuntia dillenii Haw.) juice

An integrated process coupling crossflow micro and ultra or nanofiltration was applied to separate the betacyanins in cactus pear juice (30 °C). Four microfiltration ceramic membranes (0.1–0.2 μm, 1.8–3.3 bar) and 4 ultra/nanofiltration organic membranes (0.2–4.0 kDa, 5–30 bar) were tested. Microfiltration was a first step to remove insoluble solids with low retention of soluble solids. By coupling with enzymatic liquefaction, permeate flux Jp was increased by 2 and the retention of betacyanins was limited. Ultra/nanofiltration was then used for solute separation. Retentions of solutes could be modulated by varying membrane/pressure combinations that favor rather the concentration of all the solutes or rather the purification of the betacyanins with respect to the total dry matter. Retention of individual betacyanins could be a little different which also made possible fractionation. Simulations using simple models allowed to evaluate the interest of the process for concentrating, purifying and fractionating betacyanins with a possible diafiltration step.Industrial relevanceBetacyanins are natural colorants that can be obtained from cactus pear juice, a crop of increasing interest for its agricultural potential in Sahelian regions. The aim of this study was to evaluate a new integrated process based on membrane separation allowing to concentrate or separate betacyanins from other solutes at low temperature and with a limited environmental impact. This process associates a first step to clarify the cactus pear juice by microfiltration after enzymatic liquefaction and a second step to concentrate or purify betacyanins by ultra or nanofiltration. By choosing different membrane/transmembrane pressure combinations in the 2nd step, solute retentions could be modulated in order to favor rather the concentration of all solutes or rather the separation of betacyanins from total soluble solids or even rather the fractionation of betacyanins themselves.     

膜分离技术及其在果汁加工中的应用

介绍了应用于果汁加工中的膜分离过程(微滤、超滤、纳滤、反渗透、电渗析、膜蒸馏)及其分离性能。由渗透通量和截留率表征,在果汁加工中,膜分离技术可用于果汁的澄清、浓缩、脱气、脱苦、脱酸、脱色等。