Application of Membrane Technology in Food Processing

Abstract

Membrane technology has gained momentum in food processing and other areas like desalination, separation, and concentration of enzyme treatment of processed water to remove bacteria and contaminants in the last 30 years. The important techniques of membrane technology include reverse osmosis (RO, hyperfiltration), ultrafiltration (UF), nanofiltration (NF), microfiltration (MF), ion exchange, electrodialysis, and evaporation. The major advantages of the technology are—very little change in nutrition quality, the energy used in reverse osmosis or ultrafiltration is efficiently utilized as there is no phase change and the concentration of the food solution is established by applying high pressure to reverse the direction of the flow. As compared to reverse osmosis, ultrafiltration technique is used to separate the low molecular weight solutes like salts monosaccharides and aroma compounds. In reverse osmosis the pressure applied is 5–10 times that used in ultrafiltration (4,000–8,000 × 103 Pa) is there necessary to overcome this (the term reverse osmosis). Some of the applications of this membrane technology are concentration and purification of fruit juices, enzymes, fermented liquors, and vegetable oils. The milk for example can be converted to many fractions namely whey protein solution, casein solution, protein standardized milk, milk protein concentrate, all types of casein (α, β, γ), caseinate, phophocasein, etc. using technologies of membrane filtration viz. reverse osmosis, ultrafiltration, diafiltration, microfiltration, and electrodialysis. These technologies differ in application selecting the pore size of the membrane suitable for the molecules to be separated and their molecular weight.