Solubility lactose

A solution of lactose, soluble proteins, minerals, vitamins, and other components... 

Some carbohydrates actively inhibit the crystallization of lactose, whereas others do not. Carbohydrates that are active possess either the /3-galactosyl or the 4-substituted-glucose group in common with lactose, so that adsorption can occur specifically at certain crystal faces (Van Krevald 1969). (3-Lactose, which is present in all lactose solutions [see Equilibrium in Solution (Mutarotation )], has been postulated to be principally responsible for the much slower crystallization of lactose compared with that of sucrose, which does not have an isomeric form to interfere with the crystallization process (Van Krevald 1969). Lactose solubility can be decreased substantially by the pres-... 

Some studies have been made on the effects of other sugars on the solubility of lactose (Nickerson and Moore 1972). At 10 to 18°C, a 14% sucrose solution, comparable to that in ice cream mix, reduces lactose solubility only slightly. However, the data in Table 6.3 show that concentrations of 40 to 70% sucrose reduce the solubility of lactose appreciably—to 40 to 80% of normal. At temperatures near 0°C, the solubility of lactose is reduced by about one-half by saturating the solution with sucrose. 

Percentage of lactose solubility in distilled water at the same temperature. 

Solutions of lactose are capable of being highly supersaturated before spontaneous crystallization occurs. Even then, crystallization may occur only after a considerable period. In general, the supersolubility at any temperature is equal to the saturation value at a temperature 30 °C higher. This is shown by the lactose solubility curves of Figure 6.8. 

Hunziker, O. F. and Nissen, B. H. 1927. Lactose solubility and lactose crystal formation II. Lactose crystal formation. J. Dairy Sci. 10 139-154. 

Sucrose concentration, kg/kg water (2) Lactose solubility, kg/kg water (3) Mole fraction of sugar (4) Activity coefficient (2) x (4)... 

C (rapid heating). Manufactured by the oxidation of lactose or the galactans from wood with nitric acid. When heated with water it forms a soluble lactone. Converted to furoic... 

Action of sodium hydroxide. Boil about 0 2 g. of glucose with 5 of 10% NaOH solution the mixture turns yellow, then brown, and emits the odour of caramel. Fructose, maltose, lactose and soluble starch behave similarly sucrose and ordinary starch do not give colorations. 

Disaccharides, e.g., lactose, which yield galactose upon hydrolysis, will also give the sparingly-soluble mucic acid but in poorer 3deld. This reaction may be employed for the differentiation between certain disaccharides lactose — mucic + saccharic acids sucrose — saccharic acid only maltose — saccharic acid only. 

Saccharic acid. Use the filtrate A) from the above oxidation of lactose or, alternatively, employ the product obtained by evaporating 10 g. of glucose with 100 ml. of nitric acid, sp. gr. 1 15, until a syrupy residue remains and then dissolving in 30 ml. of water. Exactly neutralise at the boiling point with a concentrated solution of potassium carbonate, acidify with acetic acid, and concentrate again to a thick syrup. Upon the addition of 50 per cent, acetic acid, acid potassium saccharate sepa rates out. Filter at the pump and recrystaUise from a small quantity of hot water to remove the attendant oxahc acid. It is necessary to isolate the saccharic acid as the acid potassium salt since the acid is very soluble in water. The purity may be confirmed by conversion into the silver salt (Section 111,103) and determination of the silver content by ignition. 

The ratio of a-lactose [10039-26-6] and P-lactose in dry milk and whey varies according to the speed and temperature of drying. An aqueous solution at equiHbrium at 25°C contains 35% a- and 63% -lactose. The latter is more soluble and sweeter than DL-lactose and is obtained by heating an 80% DL-lactose [63-42-3] solution above 93.5°C, foUowed by drying on a dmm or roUer dryer. Lactose is used for foods and pharmaceutical products. 

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. 

Natural Occurrence of ( — )-proto-Quercitol. Although the dextrorotatory form (12) of proto-quercitol was discovered in acorns more than a century ago by Braconnot (5), who at first thought that it was lactose, the levorotatory form (13) remained unknown until 1961. In that year, Plouvier isolated it from leaves of the tree Eucalyptus populnea the yield was 0.55% (36). The optical rotation of the new compound was equal and opposite to that of the dextro enantiomer, and it was identical to the latter in its crystal form, melting point, solubilities, molecular formula and infrared spectrum. 

Nutrient analysis of stabilized rice bran and its derivatives indicates that it is a good source of protein, dietary fiber and carbohydrates, in addition to several valuable phytonutrients, antioxidants, vitamins and minerals (Table 17.1). SRB and its water-soluble and water-insoluble derivatives contain all the nutrients at different levels. They are gluten and lactose free and do not give rise to any food allergy. 

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... 

Lactose, the milk sugar, is a reducing disaccharide consisting of glucose and galactose moieties. The estimated annual worldwide availability of lactose as a byproduct from cheese manufacture is several million tons [1,2], but only about 400 000 t/a lactose is processed further from cheese whey [3], Non-processed whey is an environmental problem due to its high biochemical and chemical oxygen demand [2], The use of lactose as such is limited by two main factors relatively low solubility of lactose in most solvents and lactose intolerance in human body [1]. 

Osmotic diarrhea results from the intake of unabsorbable but water-soluble solutes in the intestinal lumen leading to water retention. Common causes include lactose intolerance and ingestion of magnesium-containing antacids. 

Few tablets intended for oral administration are totally soluble in aqueous media, but if such a product is needed, then soluble excipients are employed. These include dextrose, lactose, mannitol, and sodium chloride, with the last of these sometimes acting as its own lubricant. Urea may also be used, but due to its known pharmacological effects, it is less desirable than the other soluble compounds cited. 

In a later study [133] the effect of disintegrants on hydrochlorothiazide dissolution from both soluble (anhydrous lactose) and insoluble" (dicalcium phosphate) fillers was compared for different lubricant levels and tamping forces (instrumented Zanasi LZ-64 machine). Statistical analysis of this multivariable study revealed all main factors and their interactions to... 

Lactose is a disaccharide reducing sugar. Unlike the other sugars mentioned, lactose is not particularly soluble. A property that has some use in yeast-containing products is that lactose is not fermented by baker s yeast. 

New technology has been applied to allow more whey to be used. The technology has been applied to convert the lactose into a mixture of dextrose and galactose. These two monosaccharides are both reducing sugars and the mixture is much more soluble than lactose. 

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. 

Vries et al. [3.59] described the development of a stable parenteral dosage form of the cytotoxic drug E 09. E 09 dissolves poorly in water and its solution is unstable. With the addition of 200 mg of lactose per vial containing 8 mg of E 09, an optimum formulation was developed with respect to solubility, dosage of E 09 and length of the freeze drying cycle. DSC studies have been used to select the most effective parameters. The freeze dried product remains stable for 1 year when stored at 4 °C in a dark environment. 

The mucic acid test is now only of historical interest. It depends on the oxidation of galactose or saccharides containing a galactose residue, such as lactose, with nitric acid to yield mucic acid. Mucic acid is highly insoluble in water, while the isomeric dicarboxylic acids yielded by other sugars are soluble. Mucic acid may be identified by its characteristic thallium salt. 

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