Lactose component

Figure 2 An ordered mixture and a co-spheronized formulation. The active drug particles are of the same size, while the lactose components are of very different size in the two formulations.

The different states and transitions for the lactose component in milk were described by Vuataz (2002) and can be used for better control of drying and storage. 

Milk consists of 85—89% water and 11—15% total soflds (Table 1) the latter comprises soflds-not-fat (SNF) and fat. Milk having a higher fat content also has higher SNF, with an increase of 0.4% SNF for each 1% fat increase. The principal components of SNF are protein, lactose, and minerals (ash). The fat content and other constituents of the milk vary with the animal species, and the composition of milk varies with feed, stage of lactation, health of the animal, location of withdrawal from the udder, and seasonal and environmental conditions. The nonfat soflds, fat soflds, and moisture relationships are well estabhshed and can be used as a basis for detecting adulteration with water (qv). Physical properties of milk are given in Table 2. 

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. 

Nutritional Value of Milk Products. Milk is considered one of the principal sources of nutrition for humans. Some people are intolerant to one or more components of milk so must avoid the product or consume a treated product. One example is intolerance to lactose in milk. Fluid milk is available in which the lactose has been treated to make it more digestible. The consumption of milk fat, either in fluid milk or in products derived from milk, has decreased markedly in the 1990s. Whole milk sales decreased 12% between 1985 and 1988, whereas the sales of low fat milk increased 165%, and skimmed milk sales increased 48% (35). Nutritionists have recommended that fat consumed provide no more than 30 calories, and that consumption of calories be reduced. Generally, a daily diet of 2000—3000 cal/d is needed depending on many variables, such as gender, type of work, age, body responses, exercise, etc. Further, there is concern about cholesterol [57-88-5] and density of fat consumed. Complete information on the nutritive value of milk and milk products is provided on product labels (36) (see also Table 4). 

Compressed tablets that are composed of several layers require specially adapted presses designed with several fed hoppers. For a two-layer tablet, one granulation is first fed to a die and partially compressed into a soft tablet. The second granulation is added, and the total die components then are compressed fiiUy. Such procedures are used when the tablet ingredients may be incompatible, which requires separate granulations. If needed, a layer of inert ingredient, eg, lactose, is inserted between the two. 

Lactose occurs in milk, mainly free, but to a small extent as a component of higher oligosaccharides. Cow and goat milks contain about 4.5% lactose human milk contains about 7.0%. Lactose is used as an excipient in tablets to provide bulk and rapid disintegration. It is also used in some food products where it contributes body with only about 40% the sweetness of sucrose and enhances colors and flavors. 

Whey concentration, both of whole whey and ultrafiltration permeate, is practiced successfully, but the solubility of lactose hmits the practical concentration of whey to about 20 percent total sohds, about a 4x concentration fac tor. (Membranes do not tolerate sohds forming on their surface.) Nanofiltration is used to soften water and clean up streams where complete removal of monovalent ions is either unnecessary or undesirable. Because of the ionic character of most NF membranes, they reject polyvalent ions much more readily than monovalent ions. NF is used to treat salt whey, the whey expressed after NaCl is added to curd. Nanofiltration permits the NaCl to permeate while retaining the other whey components, which may then be blended with ordinaiy whey. NF is also used to deacidify whey produced by the addition of HCl to milk in the production of casein. 

Diafiltration If a batch process is run so that the permeate is replaced by an equal volume of fresh solvent, unretained solutes are flushed through the system more efficiently. A major use of UF is fractionation, where a solvent, a retained solute and an unretained solute are present. An example is whey, containing water, protein, and lactose. If the retention of protein is I and the retention of lactose is 0, the concentration of protein in the retentate rises during UF. The ratio of protein to lac tose rises, but the feed concentration of lactose is unchanged in retentate and permeate. Diafiltration dilutes the feed, and permits the concentration of lactose to be reduced. Diafiltration is used to produce high-purity products, and is used to fractionate high-value products. R is always 0 for eveiy component. 

Entries 7, 8, and 10 describe so-called Idnetically controlled syntheses starting from activated substrates such as ethyl esters or lactose. In two reaction systems it was possible to demonstrate that ionic liquids can also be useful in a thermodynamically controlled synthesis starting with the single components (Entry 11) [39]. In both cases, as with the results presented in entry 6, the ionic liquids were used with addition of less than 1 % water, necessary to maintain the enzyme activity. The yields observed were similar or better than those obtained with conventional organic solvents. 

The carbohydrates in rice bran are made up of the cell wall components such as polysaccharides, oligosaccharides, hemicelluloses, starch and some sugars. The health benefits of rice bran polysaccharides and hemicelluloses are discussed under phytochemicals of rice bran below. It is lactose-free and gluten-free. The water-soluble non-starchy polysaccharides, oligosaccharides and hemicelluloses are concentrated in the water-soluble fraction of rice... 

As with urine, saliva (spumm) is easy to collect. The levels of protein and lipids in saliva or spumm are low (compared to blood samples). These matrices are viscous, which is why extraction efficiency of xenobioties amoimts to only 5 to 9%. By acidifying the samples, extraction efficiencies are improved as the samples are clarified, and proteinaceous material and cellular debris are precipitated and removed. Some xenobioties and their metabohtes are expressed in hair. Hair is an ideal matrix for extraction of analytes to nonpolar phases, especially when the parent xenobioties are extensively metabolized and often nondetectable in other tissues (parent molecules of xenobioties are usually less polar than metabolites). Hair is a popular target for forensic purposes and to monitor drug compliance and abuse. Human milk may be an indicator of exposure of a newborn to compounds to which the mother has been previously exposed. The main components of human milk are water (88%), proteins (3%), lipids (3%), and carbohydrates in the form of lactose (6%). At present, increasing attention is devoted to the determination of xenobioties in breath. This matrix, however, contains only volatile substances, whose analysis is not related to PLC applications. 

Some data fitting results are displayed in Figures 12.1 and 12.3. The general conclusion is that both models describe the behaviours of the main components, lactose and lactitol very well, both for sponge nickel and ruthenium catalysts. In this respect, no real model discrimination is possible. Both models also describe equally well the behaviour of lactobionic acid (D), including its concentration maximum when the reversible step is included (ks) (Figure 12.3). 

Milk components Rat Lead absorption Lactose-hydrolyzed milk does not increase lead absorption, but ordinary milk does Bell and Spickett 1981... 

Observations of person-to-person differences in the metabolism of drugs and consequently in drug kinetics and response led to the concepts of pharmacogenetics. The same principal concepts apply to the genetic variability in the reaction to food components (e.g., lactose intolerance) or to environmental toxins (e.g., carcinogens). These fields often are termed ecogenetics and toxicogenetics . 

Brew, K., Shaper, J.H., Olsen, K.W., Trayer, I.P., and Hill, R.L. (1975) Cross-linking of the components of lactose synthetase with dimethylpimelimidate. J. Biol. Chem. 250, 1434-1444. 

Lactose is normally encountered as a component of any skim milk that is used in bakery products. Small quantities of crystalline lactose are sometimes used in baked goods. If a product is made with too much lactose then a metallic taste appears. The amount of lactose that can be consumed without this taste appearing varies between individuals. 

Milk powder contains several useful components, namely protein and lactose. Lactose is a reducing sugar that undergoes the Maillard reaction to produce flavour and colour. The proteins as well as participating in the Maillard reaction have useful emulsifying abilities. These benefits are only obtained if the lactose is dissolved and the proteins dissolved or dispersed. 

Another reason for the reduced use of milk powder is the availability of substitute ingredients such as lactose, whey powder or syrups and speciality milk powder replacers. The speciality milk powder replacers are produced by the dairy industry from milk or whey components, combining them to produce a product that will act as a substitute for milk powder but is less expensive. 

The major component of whey is lactose, and while there various uses for the protein in making protein concentrates these leave a surplus of lactose. Impure grades of lactose have been available to the food industry for some time. They are relatively successful in biscuits as a raw material for the Maillard reaction to produce pleasant colours and flavours. 

One of the bars to the use of lactose as a food ingredient is its limited solubility. This can be overcome by enzymatically splitting the lactose to its component monosaccharides dextrose and galactose. These monosaccharides are much more soluble than lactose but can still undergo the Maillard reaction. If the lactose is split into its constituent monosaccharides, whey can be condensed to a relatively stable high solids syrup. These syrups tend to carry some cheese flavour notes but, where used appropriately, can contribute beneficial colours and flavours in biscuits. 

Direct connections between observed toxicity and formulation components is uncommon and it is usually assumed that vehicles and other nontest chemical components are innocuous or have only transitory pharmacological effects. Historically, however, this has certainly not been the case. Even lactose may have marked toxicity in individual test animals (or humans) who are genetically incapable of tolerating it. 

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