Casein production

Southward, C. R. (2010).Casein products, http //nzic.org.nz/ChemProcesses/dairy/3E.pdf. Accessed Sept. 24, 2010. 

It is essential to consider the physico-chemical properties of each WPC and casein product in order to effectively evaluate their emulsification properties. Otherwise, results merely indicate the previous processing conditions rather than the inherent functional properties for these various products. Those processing treatments that promote protein denaturatlon, protein-protein Interaction via disulfide interchange, enzymatic modification and other basic alterations in the physico-chemical properties of the proteins will often result in protein products with unsatisfactory emulsification properties, since they would lack the ability to unfold at the emulsion interface and thus would be unable to function. It is recommended that those factors normally considered for production of protein products to be used in foam formation and foam stabilization be considered also, since both phenomena possess similar physico-chemical and functionality requirements (30,31). 

The properties of many dairy products, in fact their very existence, depend on the properties of milk proteins, although the fat, lactose and especially the salts, exert very significant modifying influences. Casein products are almost exclusively milk protein while the production of most cheese varieties is initiated through the specific modification of proteins by proteolytic enzymes or isoelectric precipitation. The high heat treatments to which many milk products are subjected are possible only because of the exceptionally high heat stability of the principal milk proteins, the caseins. 

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... 

Induction of milk proteins appears to involve increased transcription of the appropriate genes. Levels of mRNA for casein increase substantially [66,69,74-77] (Fig. 6), though to a lower extent than the increase in casein production, suggesting that an increased rate of translation of mRNA (or possibly decreased protein degradation) may also be important. The increased levels of mRNA may be partly due to decreased degradation as well as increased transcription [74]. 

Despite the many consumer and wood gluing uses mentioned here, an estimated 75% of casein production went into paper coatings until World War II (4). Casein use for adhesives reached its peak in 1973, at about 121 million dry pounds (5). Today, very little casein glue is used by household consumers, paper coaters, and plywood manufacturers. In 1986, nearly all U.S.-casein adhesive production was used by the door manufacturing industry, where the total volume was less than 10 million pounds. 

Due to the economic incentives for conversion of skim milk to powdered lowfat milk in the United States and Canada, nearly all of the casein used by U.S.-adhesives manufacturers comes from overseas. Casein has, at various times, been imported from 20 different countries. Australia, New Zealand, Uruguay, France, Norway, Holland, Ireland, and Argentina are probably the most important producers in the Western World today. The worldwide nature of casein production leads to a wide range in product quality. 

However, the procedures used in the dairy industry, rennet and acid casein, have the disadvantages to produce large volume of chemical effluents due to the addition of bases and acids during treatments, and to generate inherent risk linked to handling, stocking, and transportation of concentrated bases and acids. In acid casein production, milk pH is decreased to the isoelectric point of the casein by addition of strong acid (hydrochloric, sulfuric, nitric, lactic, etc.). H" " concentration of milk is increased... 

FIGURE 21.16 Processes for casein and caseinate production. (Adapted from Mulvihill, D.M., Caseins and caseinates Manufacture. In Fox, P.F., Ed. Developments in Dairy Chemistry, Vol. 4, Elsevier Applied Science Publishers, London, 1989, pp. 97-129.)... 

Lactose is a natural disaccharide consisting of galactose and glucose and is present in the milk of most mammals. Commercially, lactose is produced from the whey of cows milk whey being the residual liquid of the milk following cheese and casein production. Cows milk contains 4.4-5.2% lactose lactose constitutes 38% of the total solid content of milk. 

The use of ED with a monopolar membrane for protein separation and acid caseinate production and in bioreactors for organic acid production is a well-proven technology with huge operating systems worldwide. Such ED is applied to different food systems, which include (Bazinet, 2004)... 

Buckets, plastics Buoys and floats, plastics Caps, plastics Carafes, plastics Casein products, molded for the trade... 

Lactose, a cheap and abundant carbohydrate by-product of cheese and casein production, can be oxidized to lactobionate and 2-ketolactobionate (1-carboxylactu-lose) (Figure 4) which are intermediates in the preparation of biodegradable surfactants. 

Figure 3 Allergenicity of cow s milk casein and of enzymatically modified cow s milk casein products. (1) Cow s milk casein (2) a-chymotryptic hydrolysate of casein (3,4) EPM products without Met enrichment (5) EPM product with Met incorporation (6,7) FPLC fractions of EPM products (8) commercial hypoallergenic formula.

Water-Soluble Proteins. Historically, several water-soluble plant and animal proteins have been used as adhesives, both industrially and in conservation work. Currently, only the milk-based casein products are in significant industrial use. Casein glues have also been used in conservation work, but formulations designed for high water resistance could be difficult to reverse. Plant proteins, especially those from legumes such as soybeans and peanuts, have been used industrially, some until fairly recently. Presumably at least some forms of plant protein glues would be reversible enough to be of interest to conservators. 

Milk (casein) products used as fining agents in cider and wines... 

Whey is a by-product of cheese or casein production and has several uses including encapsulation. 

Southward CR. Casein products chemical processes in New Zealand. New Zealand New Zealand Dairy Research Institute 1998. p. 1-13. 

Plastics. Journal for the manufacture and application of processed or chemically fabricated materials with special consideration of artificial silk and other man-made fibers, of vulcanized, devulcanized (reclaimed) and synthetic caoutchouc, guttapercha etc. as well as substitute materials, of celluloid and similar cellulose products, of man-made leather and leather fabrics (linoleum), of resins, casein products etc. 

Decanters in casein production will often have a centripetal pump discharge to combat foam, and axial flow, as well as clean-in-place systems. Lactose production uses a double-lead conveyor, with on-the-beach rinsing, and a reslurry rinse solids collector, as well, again, as CIP. 

About 50 years ago, the major uses of casein were in technogical appUcations, but nowadays casein products are regularly used as food additives, for example as ingredients that enhance some physical properties of foods, such as whipping, foaming, water binding, thickening and emulsification and nutritional properties. 

NeoCryl BT-207, a water-based acrylic emulsion, is a viable alternative to natural casein products that have been predominantly used in this market. Historically, adhesive formulators have faced major difficulties when replacing natural casein-based adhesives for bottle labeling applications. Manufacturers of synthetic polymers struggled to match the full performance range and benefits of casein. However, due to issues with supply constraints, consistent quality and the price volatility of casein, there is a real need to find a synthetic alternative. 

In 1985 and 1986 the casein sources which played a significant role in the adhesive industries were New Zealand, Australia, France, Ireland, Uruguay, Russia, and Poland. Argentina, one of the major suppliers to the adhesive industry in the 1960s and 1970s, has cut its casein production to the point that Argentine casein comprised less than 1% of the casein imports in 1985, and none in 1986 and 1987. ... 

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