Reviewing fundamental and essential works of traditional membrane systems, advanced functional membranes are discussed with both organic and inorganic ones. Furthermore, for development of new field of membrane science and technology, electro-and photoactive functional membrane whose transporting guests are electron (hole) and photon, are described with several examples ; such as various devices of functional molecule incorporating conducting polymer membrane, ultrahigh anisotropic conducting polymer membrane, photoemission energy controllable membrane superlattice of quantum functional semi-conducting conjugating polymer multilayers membrane. These pioneering membranes shall play big drama of membrane science and technology in the future.

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The Gross Domestic Product (GDP) of Japan has become the second largest, after that of the USA, in the world. Therefore, it is necessary that Japan develops its original technologies instead of following and improving those developed in other counties.
Recently, it has been said that the collaboration of industry, academic and government is essential in order to attain this target. Fortunately, in the area of membrane science and technology development for food processing, these three groups as mentioned above have been collaborating for the last 15 years.
In this paper it will be discussed what the characteristics of the industry, academic and government are, and how they can collaborate better. Also the history of the collaborative research association of membrane technology for food processing will be described which was promoted by the ministry of agriculture, forestry and fisheries, and the membrane research circle of food which is a non-governmental organization.

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Membrane filtration systems : Microfiltration (MF), Ultrafiltration (UF), Nanofiltration (NF), Electro-dialysis (ED), Bi-polar (BP), and Vapor permeation (VP) in Japanese brewing industry are reviewed. Some of them have been successfully applied to the brewing industry for developing value-added new products, reducing production cost and have been researched as alternative processes to traditional ones. MF with non-heat bacteria elminating process for Japanese rice wine and draft beer, NF for decolored soy sauce and ED for low salt soy sauce have been indispensable porocesses and the consumption of those brewing products has been steadily increasing these 30 years. In refining raw soy sauce and soy sauce lees, plate & frame modules of MF & UF have been successfully used in place of diatomaceous earth filtration. They are compared each other with the energy consumption. The ratio of permeate volume (P) and total energy consumption (E) : P/E is proposed to selecting the best filtration module for recovery of soy sauce from the lees. ED/BP membrane system has been experimentally investigated for desalting soy sauce. VP with activated carbon adsorbent has been under development for recovery and concentration of alcohol vapor which is aerated and exhausted from the fermented soy sauce moromi-mash. These membrane systems related to the advanced soy sauce manufacturing are summarized schematically.

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In order to estimate the effects of fouling layer and osmotic pressure on the performance of membrane separation system quantitatively, the concentration polarization equation and the membrane transport equation based on nonequilibrium thermodynamics are applied to membrane processes for liquid foods, and new mathematical models are proposed. The efficiency of the membrane processes could be expressed by the new models precisely. By using these models, some membrane processes for food industry are optimized and their feasibility evaluation is described.

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It goes back for 25 years in 1972, low pressure reverse osmosis (RO) membrane was developed in USA. Since that time, this low pressure RO membrane has been made rapid progress in producing of semiconductor-grade water in Japan. On the other hand, in USA and Europe, the low pressure RO membrane has been greatly developed for desalination of brackish water and refinement or condensation in food processing.
Later we will explain the latest information of the low pressure composite RO membranes, especially in respect of the forefront of the ultra low pressure RO membrane which was developed for saving the energy and in respect of the module for food processing or vessel structure.

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In the early stage of membrane technology in the food industry, the technology was so immature that applying the technology into the food industry caused many troubles to be solved. Some of the membrane plants were forced to shut down because the troubles could not be solved.
Fortunately most of the troubles were eventually resolved or tamed anyhow. Thus, these days, the membrane technology has been used for many fields in the food industry.
Nowadays, how to operate the membrane plant effectively becomes more important. Operation management system of it consists of two parts : the one built in the plant as hardware and the other built up after installation of it as software. Key points of them were reviewed.

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Protein recovery performance by anion-exchange interaction was compared between a functionalized porous hollow-fiber membrane and a bead-packed column under identical conditions. The membrane exihibited higher flow rate than the column. Protein dynamic binding capacity of the membranes was constant irrespective of flow rate and higher than that of the column. These facts indicate that functionalized porous hollow-fiber membranes will be effective for high-speed protein recovery from large volume of biological fluids. Protein recovery performance of the functionalized hollow-fiber membrane was also evaluated in a module form. Flow rate and protein binding amount of the module increased linearly with the number of fibers in the module. This lineality between the module and the single hollow fiber is favorable to scaling-up for protein recovery.
Hydrophobic ligands, such as phenyl and butyl groups, were appended to a grafted polymer chain on a pore surface of a porous polyethylene hollow-fiber membrane with pore size of 0.2 μm. Favorable kinetics, wherein an increasing flow rate provides an increasing binding rate of protein, were also observed. High elution percentage of protein was attained by control of the hydrophobic-ligand site on the grafted polymer chain.

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New types of cation-exchange membranes were prepared by grafting acrylic acid to substrates such as microporous polyethylene and homogeneous poly [1- (trimethylsilyl) -1-propyne] by the use of plasma graft polymerization technique. Ethylenediamine was immobilized by the electrostatic force in the ion exchange membranes as the carrier of CO₂ and the facilitated transport of CO₂ through the grafted membranes was studied. The obtained membrane showed remarkably high selectivity of CO₂ over N₂ and high CO₂ permeance. The newly prepared membrane was also stable. Membrane having tertiary amine group which has an affinity for CO₂, was also prepared by plasma grafting of 2- (N, N-dimethyl) aminoethyl methacrylate. It was suggested that the membrane acts as a fixed reaction site membrane under the water-containing condition. Furthermore, an approximate solution on the facilitated transport of CO₂ through a liquid membrane containing primary or secondary amine has been developed. The effect of chemical equilibrium constant on CO₂ permeance was quantitatively clarified by the simulation based on this approximate solution.

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The preparation process of poly (phenylene sulfone) (PPSO) hollow-fiber membrane has been developed. PPSO membrane has extremely high durability against heat, oxidizing chemicals, and solvents. The membrane modules have been fabricated with potting resin and casings resistant to heat, chemicals, and solvents. The preparation procedure was briefly mentioned and the characteristics of the PPSO membranes were showed with some experimental results.

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