Whey proteins ultrafiltration

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. 

Whey protein concentrates (WPC), which are relatively new forms of milk protein products available for emulsification uses, have also been studied (4,28,29). WPC products prepared by gel filtration, ultrafiltration, metaphosphate precipitation and carboxymethyl cellulose precipitation all exhibited inferior emulsification properties compared to caseinate, both in model systems and in a simulated whipped topping formulation (2. However, additional work is proceeding on this topic and it is expected that WPC will be found to be capable of providing reasonable functionality in the emulsification area, especially if proper processing conditions are followed to minimize protein denaturation during their production. Such adverse effects on the functionality of WPC are undoubtedly due to their Irreversible interaction during heating processes which impair their ability to dissociate and unfold at the emulsion interface in order to function as an emulsifier (22). 

The procedure used for the industrial production of acid (isoelectric) casein is essentially the same as that used on a laboratory scale, except for many technological differences (section 4.15.1).The whey proteins may be recovered from the whey by salting out, dialysis or ultrafiltration. 

Industrially, whey proteins are prepared by ultrafiltration or diafiltration of whey (to remove lactose and salts), followed by spray drying these products, referred to as whey protein concentrates, contain 30-80% protein. 

Ultrafiltration/diafiltration of acid or rennet whey to remove varying amounts of lactose, and spray-drying to produce whey protein concentrates (30-80% protein). 

Ion-exchange chromatography proteins are adsorbed on an ion exchanger, washed free of lactose and salts and then eluted by pH adjustment. The eluate is freed of salts by ultrafiltration and spray-dried to yield whey protein isolate, containing about 95% protein. 

In addition to the general decrease in viscosity with increasing temperature, heating milk can also influence its rheology by heat-induced denatura-tion of cryoglobulins and/or other whey proteins. Concentration of milk, e.g. by ultrafiltration, prior to heating results in a greater increase in f/app than in milk heated before concentration. 

Ruegg, M., Moor, U. and Blanc, B. 1977. A calorimetric study of the thermal denatura-tion of whey proteins in simulated milk ultrafiltrate. J. Dairy Res. 44, 509-520. 

Proteins that remain in whey after removing casein from milk are recovered as whey protein concentrates by precipitation with added polyphosphate or other polyvalent anionic compounds, ultrafiltration, ion exchange adsorption, gel filtration, or a combined acid and heat precipitation process. Whey protein concentrates are also manufactured by a combined process involving electrodialysis, concentration, lactose crystallization, and drying (Richert 1975 Morr 1979 Marshall 1982 Anon. 1982 Muller 1982B). 

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... 

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... 

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],... 

Whey protein concentrate. The whey protein used was prepared by ultrafiltration and spray drying. Protein content (N x 6.55) was 68% (dry weight). Lipid content was 7.1% (dry weight). In order to study heat induced aggregation by spectrophotometric methods the turbidity of the dilute protein dispersions was too high. The turbidity of whey protein dispersions is caused by lipids associated with proteins probably in the form of emulsified oil droplets. This fraction was removed by precipitation at pH 4.5 from dispersions made in dist. water and separated by centrifugation at 40 000 xg. 

The three proteins chosen for this study are a mildly produced soy protein isolate, kindly provided by Central Soya, a commercially available sodium caseinate (DMV, Holland) and a whey protein concentrate (WPC) obtained by ultrafiltration (UF) and spray drying of cheese whey. Analysis of the proteins is given in (4) and (11). The present protein products have been investigated , when dispersed in distilled water and in 0.2 M NaCl solution at pH 7 denoted as (0 - 7) and (0.2 - 7), respectively. 

Filtration of small (nano) particles from solvent using a filter with extremely small pores (0.001-0.010 micron) finer than ultrafiltration, not as fine as reverse osmosis. Used for the removal of viruses from plasma protein products. See Yaroshchuk, A.E., Dielectric exclusion of ions from membranes, Adv. Colloid Interface Sci. 85,193-230,2000 Rossano, R., D Elia, A., and Riccio, R, One-step separation from lactose recovery and purification of major cheese-whey proteins by hydroxyapatite — a flexible... 

Concentration of whev proteins. As mentioned earlier, microfiltration can be used to remove bacterias. In addition, they are capable of separating phospholipids, fats and casein fines of sweet whey or sour (acidified) whey. Ultrafiltration of whey has been well proven to provide an array of protein products of diverse compositions and properties. Inorganic membrane filtration can be used at different stages of the process to make whey protein concentrates (WPC) in powder form with a protein content reaching 50%. 

Nilsson JL. EouUng of an ultrafiltration membrane by a dissolved whey protein concentrate and some whey proteins. J. Membr. Sci. 1988 36 147-160. 

Ultrafiltration processing for whey proteins concentration and fractionation, for recovery of lactose from milk and whey, for total milk protein concentration for the production of milk protein concentrate (MFC) or nulk protein isolate (MPl), for milk standardization for continuous mechanized manufacture of cheese and other fermented products, and for production of high-solids milk base for dried milk production. 

Ultrafiltration may be integrated into the cheesemaking process either for partial milk concentration or full milk concentration (Table 22.1), in which cutting and whey drainage are entirely eliminated and 100% of the whey proteins of milk are retained in the cheese matrix [28,75,76], The reduced volume of the liquid pre-cheese and the absence of whey drainage from the curd when UF pre-cheese is used lead to the reduction of rennet requirement by -80% compared to what is usually needed in conventional manufacture of cheese [25,77],... 

Lee, F.Y. and White, C.H., Effect of ultrafiltration retentates and whey protein concentrates on ice cream quality during storage, J. Dairy Sci., 14, 1170, 1991. 

Cabero, M.L., Riera, F. A., and Alvarez, R., Rinsing of ultrafiltration ceramic membranes fouled with whey proteins Effects on cleaning procedures, J. Membr. Sci., 154, 239, 1999. 

Fig. 1 Comparison of the two standard chemicals of a-lac-talhumin and P-lactoglohulin and whey proteins after ultrafiltration (MWCO 30,000) hy RP-HPLC (buffer A/huffer B=70/ 30-35/65 vol.%, gradient time of 15 min).

Lieske, B. Konrad, G. Physico-chemical and functional properties of whey protein as affected by limited papain proteolysis and selective ultrafiltration. Int. Dairy J. 1996, 6(1), 13-31. 

In the manufacture of fresh cheeses, e. g. quark, the pasteurised skim milk is inoculated with micro-organisms (Sc. lactis, Sc. cremoris). To accelerate the thickening, the enzym chymosin is added. After ripening - with a pH value of about 4.6 - the coagulated milk must be pumped through a separator, possibly including an ultrafiltration system, in order to separate the sour whey. The ultrafiltration would separate the whey into 2 phases the permeate (water soluble) and the retentate (protein phase). Finally the quark, retentate, cream, (fruit) preparations, flavourings or spices and herbs are added. 

Ultrafiltration Whey protein concentrate Edible protein ... 

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