Ultrafiltration, cheese

K. marxianus var. fragilis which utilizes lactose, produces a food-giade yeast product from cheese whey or cheese whey permeates collected from ultrafiltration processes at cheese plants. Again, the process is similar to that used with C. utilis (2,63). The Provesteen process can produce fragiUs yeast from cheese whey or cheese whey permeate at cell concentrations ia the range of 110—120 g/L, dry wt basis (70,73). 

Ultrafiltration. Membranes are used that are capable of selectively passing large molecules (>500 daltons). Pressures of 0.1—1.4 MPa (<200 psi) are exerted over the solution to overcome the osmotic pressure, while providing an adequate dow through the membrane for use. Ultrafiltration (qv) has been particulady successhil for the separation of whey from cheese. It separates protein from lactose and mineral salts, protein being the concentrate. Ultrafiltration is also used to obtain a protein-rich concentrate of skimmed milk from which cheese is made. The whey protein obtained by ultrafiltration is 50—80% protein which can be spray dried. 

Membrane-retained components are collectively called concentrate or retentate. Materials permeating the membrane are called filtrate, ultrafiltrate, or permeate. It is the objective of ultrafiltration to recover or concentrate particular species in the retentate (eg, latex concentration, pigment recovery, protein recovery from cheese and casein wheys, and concentration of proteins for biopharmaceuticals) or to produce a purified permeate (eg, sewage treatment, production of sterile water or antibiotics, etc). Diafiltration is a specific ultrafiltration process in which the retentate is further purified or the permeable sohds are extracted further by the addition of water or, in the case of proteins, buffer to the retentate. 

J. L. Maubois, "AppHcation of Ultrafiltration to Milk Treatment for Cheese Making," in Ref. 27. 

The largest industrial use of ultrafiltration is the recovery of paint from water-soluble coat bases (primers) applied by the wet electrodeposition process (electrocoating) in auto and appliance factories. Many installations of this type are operating around the world. The recovery of proteins in cheese whey (a waste from cheese processing) for dairy applications is the second largest application, where a... 

Ultrafiltration (UF) is used for the separation and concentration of macromolecules and colloidal particles. Ultrafiltration membranes usually have larger pore sizes than RO membranes, typically 1 to 100 nanometer (nm). Operating pressures are generally low (30-100 psig). Applications include electropaints, gray water, emulsions, oily wastes, and milk, cheese, and protein processing. 

Processes for crystallization of lactose are well established, with production generally limited to a few large plants. Although a variety of cheese wheys and whey ultrafiltrates can be used for lactose production, sweet whey or ultrafiltrates are preferred (Woychik 1982). The crystallization process has three basic steps ... 

Rash, K. E. and Kosikowski, F. V. 1982. Influence of lactic acid starter bacteria on enteropathogenic Escherichia coli in ultrafiltration prepared Camembert cheese. J. Dairy Sci. 65, 537-543. 

Krause et al. (44) extensively studied the derivatization with DBS, proposed by Chang et al. (76), since DBS reacts with both primary and secondary amines and amino acids at room temperature, leading to stable products detectable in the visible region with high sensitivity. In particular they developed a method for the analysis of BAs, together with the AA, in cheese, seasonings, rice wine, and ham. The deproteinized samples (by ultrafiltration or acidification with TCA) were derivatized with an automated precolumn method and analyzed by RP-HPLC-UV. The DBS derivatization was successively applied to study the occurrence of BAs and free AA in raw-milk cheese (detection at 436 nm). They found that the proportions of free AA and BAs relative to the total amount fell into three broad groups that were independent of the type and ripeness of the cheese (77). 

Ultrafiltration is a French originated process that uses a membrane filtering system. In its raw form, whey contains protein, lactose, ash, and some minerals. This should not surprise anyone since whey is the bi-product of cheese or casein production from milk. The original ultrafiltration method separated the ash and lactose from the whey protein resulting in a product providing about 35-70% protein. As the process improved the protein, content was elevated to up to 80% -86.5% protein content. Ultrafiltration provides a decent product with... 

Because of the challenging environment in which ultrafiltration membranes are operated and the regular cleaning cycles, membrane lifetime is significantly shorter than that of reverse osmosis membranes. Ultrafiltration module lifetimes are rarely more than 2-3 years, and modules may be replaced annually in cheese whey or electrocoat paint applications. In contrast, reverse osmosis membranes are normally not cleaned more than once or twice per year and can last 4-5 years. 

Figure 6.22 Simplified flow schematic showing the traditional cheese production method, and two new methods using ultrafiltration to increase the recycle of useful product...

The second whey separation process uses both ultrafiltration and reverse osmosis to obtain useful protein from the whey produced in the traditional cheese manufacturing process. A flow schematic of a combined ultrafiltration-reverse osmosis process is shown in Figure 6.23. The goal is to separate the whey into three streams, the most valuable of which is the concentrated protein fraction stripped of salts and lactose. Because raw whey has a high lactose concentration, before the whey protein can be used as a concentrate, the protein concentration must be increased to at least 60-70% on a dry basis and the lactose content... 

Figure 6.23 Simplified flow schematic of an ultrafiltration/reverse osmosis process to extract valuable components from cheese whey...

Although whey protein products have several food uses, the lactose contained in the permeate is less valuable, and many plants discharge the permeate to a biological wastewater treatment plant. A few plants recover lactose as dry lactose sugar, as shown in Figure 6.23. Some plants also ferment the lactose concentrate to make ethanol. An introduction to membrane ultrafiltration in cheese production is given by Kosikowski [26],... 

Ultrafiltration Liquid Microporous membrane with pressure gradient Separation of whey from cheese... 

Fukumoto, L.R., Li-Chan, E., Kwan, L., and Nakai, S. 1994b. Isolation of immunoglobulins from cheese whey using ultrafiltration and immobilized metal affinity chromatography. Food Res. Int. 

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