Lactose removal from whey

Some individuals are unable to metabolise lactose and are lactose intolerant. This is because they lack the enzyme lactase that is needed to metabolise lactose. Lactose intolerance is common in those parts of the world where humans do not consume any dairy products after weaning. In practice this means in Asia, which means that most of the world s population might be lactose intolerant. It is possible to produce lactose removed skim milk. Another approach with lactose is to hydrolyse it to its constituent monosaccharides. As well as avoiding lactose intolerance this allows a syrup to be produced from cheese whey. These syrups are offered as an ingredient for toffees and caramels. 

Whey, Reduced Lactose, occurs as either a liquid or a dry product. It is the substance obtained by the selective removal of lactose from whey. Removal of lactose is accomplished by physical separation techniques such as precipitation, filtration, or dialysis. The acidity of Reduced Lactose Whey may be adjusted by the addition of safe and suitable pH-adjusting ingredients. The final product is pasteurized. 

It is possible to produce lactose-removed skim milk. Another approach with lactose is to hydrolyse it to its constituent monosaccharides. As well as avoiding lactose intolerance this allows a syrup to be produced from cheese whey, and these syrups are offered as an ingredient for toffees and caramels. 

Definition Substance obtained by removal of lactose from whey as fluid, cone., or dried Uses Food additive, binder Regulatory FDA 21CFR 135.110, 135.140,... 

Buttermilk. Buttermilk is drained from butter (chum) after butter granules are formed as such, it is the fluid other than the fat which is removed by churning. Buttermilk may be used as a beverage or may be dried and used for baking. Buttermilk from churning is - 91% water and 9% total sohds. Total sohds include lactose [598-82-3] 4.5% nitrogenous matter, 3.4% ash, 0.7% and fat, 0.4%. Table 17 gives the U.S. specifications for dry buttermilk (DBM) and whey. 

Following ultrafiltration of whey, the permeate passes over a reverse osmosis (qv) membrane to separate the lactose from other components of the permeate. Reverse osmosis can be used to remove water and concentrate soHds in a dairy plant, giving a product with 18% soHds and thus decreasing the difficulty of waste disposal. Concentration of rinse water gives a product with 4—5% total soHds. Proper maintenance of the membrane allows for use up to two years. Membranes are available for use up to 100°C with pH ranges from 1 to 14 the usual temperature range is 0—50°C. 

Whey protein concentrates (WPC) are produced by a variety of processing treatments to remove both lactose and minerals (20) as indicated in Figure 5. Even though it would be highly desireable to remove most of the lactose and minerals in these processes, it is not practical from an economic standpoint and thus most of these products only range in protein content from 35 to 50 %.The major objective of most of these processes is to produce a WPC with minimal protein denaturation in order to obtain a product with maximum protein solubility and functionality. However, from a practical consideration this objective is not readily obtainable, and thus most WPC products commercially available exhibit variable whey protein denaturation and functionality (20). 

Manufacture of crystalline lactose from permeate derived by ultrafiltration of lactic casein whey presents special problems because of the low pH, high lactate concentration, and high calcium and phosphate concentrations (Hobman 1984). Research at the New Zealand Dairy Research Institute has led to a pilot-scale process whereby calcium phosphate complexes are partially removed before evaporation by an alkali and heat treatment to precipitate them, followed by centrifugation to clarify the treated permeate. Removal of about 50% of the calcium is sufficient to avoid problems during evaporation. 

A general, recent trend has been to apply the principles of ion exchange to the purification of whey or lactose solutions. Anionic and cationic exchange resins are used to remove impurities from the solution, which can then be condensed and crystallized or spray-dried directly. Ahlgren (1977) and Delaney (1976) have reviewed developments... 

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). 

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... 

With the objective of increasing calcium and lactose content of MF retentate in addition to micellar casein whUe maximizing whey protein depletion. Nelson and Barbano [114] developed a multistage MF process that removed -95% of whey protein from skim milk. They reported that the MF retentate produced from this process contained soluble minerals, NPN, and lactose similar to the original milk. This was accomplished by using the permeate from the UF of the MF permeate to diafilter the MF retentate after achieving a concentration factor of 3 in the MF. Aside from the recovery of native micellar caseins, they showed that the process enabled the production of whey protein stream (UF retentate) with protein content similar to that of commercial WPC. 

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