Whey treatment

The whey proteins, lactalbumin and lactoglobuUn, constitute up to 20 % of the total protein content in milk, which are wasted during the industrial processes and may 

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FIGURE 21.36 Cheddar cheese whey treatment hy conventional electrodialysis and EDBM before final centrifugation. 

Neutral lactase (p-Galactosidase) is an enzyme produced on an industrial scale, which catalyzes the hydrolysis of lactose. Industry utilizes this enzyme in the production of low-lactose dairy products, whey treatment, and fermented lactic products. The goal of this study is to demonstrate that a new colorimetric method to measure the enzymatic activity is adequate for use as a standard method. 

Figure 3.90 Flow schematic of two-stage (UF/RO) membrane process for whey treatment.

Lactase Yeast, mold Delactosed milk and daity products whey treatment and upgrading... 

Integrated membrane process scheme for cheese whey treatment. MF = microfiltration UF = ultrafiltration NF = nanofiltration RO = reverse osmosis. 

New methods of cheese making aim at including the whey proteins in the curd, instead of removing them with the whey. Apart from giving higher yields (12-18%), these processes help to economize on waste water costs or elaborate whey treatments (cf. 10.2.10). 

Casein. Milk contains proteins and essential amino acids lacking in many other foods. Casein is the principal protein in the skimmed milk (nonfat) portion of milk (3—4% of the weight). After it is removed from the Hquid portion of milk, whey remains. Whey can be denatured by heat treatment of 85°C for 15 minutes. Various protein fractions are identified as a-, P-, and y-casein, and 5-lactoglobulin and blood—semm albumin, each having specific characteristics for various uses. Table 21 gives the concentration and composition of milk proteins. 

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. 

Parallel to the activities in the treatment of pernicious anemia were observations in the 1930s that most farm animals had a requirement for an unknown factor beyond the vitamins then known. The lack of this factor became apparent, eg, when chicks or pigs fed a diet with only vegetable protein evidenced slow growth rate and high mortahty. It became apparent that the requited factor, termed animal protein factor, was present in animal sources such as meat and tissue extracts, milk whey, and cow manure. Subsequent to its isolation, it was rapidly shown that vitamin B 2 is the same as animal protein factor. 

Also, pilot plant and laboratory scale anaerobic studies have demonstrated successful treatment of wastewaters of 5,000 to 50,000 mg/L GOD from corn chips containing soluble and colloidal corn starch and protein, cheese whey, organic chemicals, food, bakeiy, breweiy, paper mill foul condensate, paint, and numerous other hazardous anci non-hazardous materials. 

Application Paint recovery Whey processing Biologicals Water treatment Juice processing... 

These assumptions were confirmed by the electrophoresis study of the washed creams. Electrophoresis of purified fat globules is a convenient method to characterize and quantify proteins adsorbed at the oil-water interface [35]. Electrophoretic data indicate that no casein, nor whey proteins, were adsorbed at the surface of raw-milk fat globule. Upon homogenization, caseins adsorbed preferentially at the lipid-water interface. In this case, bound a-lactalbumin accounted for 16% of the total interfacial proteins. Heat treatment also induced the interaction of proteins with the fat globules. The amount of bound proteins (per mg of lipids) for heated raw milk was half that for homogenized milk. 

Reverse osmosis (RO) pressure difference desalination of sea/brackish water concentration of whey and fruit juice waste water treatment... 

Horan, N. T, Biological Wastewater Treatment Systems, John Whey Sons, Chichester, England, 1990, 233. 

The heat treatment leads to whey proteins becoming adsorbed, altering the behavior of the micelle. Dehydration by ethanol, for example, leads to aggregation of the micelles. 

In 1997, the technology was incorporated into Thiokol Corporation s waste treatment facility near Brigham City, Utah (D22204Y, p. A58). This system initially used brewer s yeast and a cheese-whey mixture as nutrient sources. In an effort to reduce costs, these additives were replaced with a carbohydrate by-product. As a result, chemical and nutrient costs dropped by more than 90%, from approximately 1.76 to 0.16 per pound of perchlorate removed (D22204Y, p. A59). 

Hydrogen peroxide is used as a sterilant or preservative for milk and whey it destroys harmful micro-organisms. Any excess hydrogen peroxide left in the milk or whey after treatment can be decomposed to water and oxygen using an enzyme (catalase). 

The hydrolysis of lactose conveys a number of desirable properties to whey—increased sweetness for one. Lactase-treated whey can be used as a sweetener in various foods such as ice cream, bakery products, beverages and corrfectionery. This treatment can save large qrrantities of whey from going to waste and presenting a potential pollution hazard. 

Lactose ciystalhzes easily, so that concentration prior to transportation of whey for treatment can be difficult. Whey is very prone to microbial contamination so that maintenance of hygienic operation conditions is a major processing problem, especially as the lactases are not thermostable and so contamination cannot be prevented by operating at elevated temperatures. 

Despite the huge quantities of whey produced, production is geographically veiy dispersed. Therefore there are few plants with a big enough out-put to allow cost-effective treatment, especially when taking into account transportation costs. 

Other Protein Components. Other protein components In complex food systems and In protein Ingredient preparations may Interfere with or modify gelation reactions. Protein Interaction between whey protein and casein upon heating has a profound Influence on the characteristics of the casein gel structure In cheesemaking. Similarly protein Interactions are Important to meat structures. Protein-protein Interaction between soy and meat proteins has also been demonstrated with heat treatment (28). While concrete Interaction data have not been collected on protein gels formed from protein combinations, gelation properties of whey proteln/peanut flour blends have been Investigated GU) ... 

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