A-Lactose

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. 

Lactose, and the lactose ia substances such as milk and whey, has been hydroly2ed commercially by enzymes to yield products that can be tolerated physiologically much more easily by people who have a lactose iatolerance (40—42). 

In bacteria, accumulation of substrates against a concentration gradient can occur through two main classes of transport systems (see [30] for a summary). The prototype of the first class of transporters is the /3-galactoside permease of Escherichia coli (see [31]). It is a relatively simple system involving only a single membrane-bound protein. It catalyzes a lactose-H symport. Other transporters... 

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]. 

Prior to the first hydrogenation batches, the supported ruthenium catalysts were reduced in the autoclave under hydrogen flow at 200°C for 2 hours (10 bar H2, heating/cooling rate 5°C/min). As the catalyst had been reduced, a lactose solution saturated with hydrogen was fed into the reactor rapidly and the hydrogen pressure and reactor temperature were immediately adjusted to the experimental conditions. Simultaneously, the impeller was switched on. This moment was considered as the initial starting point of the experiment. No notable lactose conversion was observed before the impeller was switched on. 

WjU 4-0-/ -D-Galactopyranosyl-a-D-glucopyranose, monohydrate (a-lactose, monohydrate) LACTOS01, 10 30 453... 

Ludipress a-Lactose monohydrate, povidone, crospovi-done BASF... 

I. Vrasidas, J. Kemmink, R. M. J. Liskamp, and R. J. Pieters, Synthesis and Cholera Toxin binding properties of a lactose-2-aminothiazoline conjugate,... 

Figure 7.14 The reaction of an amine-containing dendrimer with mono(lactosylamido) mono(succinimidyl)sub erate results in the attachment of a lactose unit via an amide bond.

Studies of small bowel transit time have demonstrated a great variability both within and between individuals. When the hydrogen breath test was performed under fasting conditions, using 10 ml of lactulose, the coefficient of variation amounted to 18%. Di Lorenzo et al. [129] showed that variations under fasting conditions are partly accounted for by the phase of the migrating motor complex at the intake of test solution. Moreover, when a lactose-containing meal was used, the coefficient of variation was reduced to 4% [130],... 

Fig. 7 Relation of tablet crushing strength and surface area of selected size fractions of anhydrous a-lactose, which had been compressed at 37.5 mPa. Data are shown for initial size fractions of (A) 24-32 /am, (B) 32-63 /am, (C) 63-100 /am, (D) 100-160 /am, (E) 160-200 /am, and (F) 250-315 /am. (Data adapted from Ref. 51.)...

Flow behavior of powders is also of interest in direct compression. It is generally accepted that the flow rate initially increases with particle size, achieves a maximum in the range of 100-400 /um, and then decreases [85]. An excipient that has been well characterized is lactose, which undergoes particle fragmentation when compacted. For a-lactose monohydrate, it has been shown that the... 

Goppert (G7) recommended in 1917 that lactose should be replaced by other sugars in the diet of galactosemics and that a lactose-free diet should be given from as early an age as possible. These 2 principles have formed the basis of all attempts at treating galactosemia. 

Fischer then examined the lactose yeast in the same manner as he did the Frohberg yeast and found it to contain both an invertin-like enzyme and a lactose-cleaving enzyme, which he termed lactase. From these results he concluded that the first step in the fermentation of lactose, as for the fermentation of sucrose and maltose, is the hydrolysis of the disaccharide to mono-sacharide. From this observation, he drew the landmark conclusion that he considered it most unlikely that any polysaccharide (the term included di-saccharides) can be fermented without first being hydrolyzed to hexose (31). 

The influence of -lactose on the growth of crystals of a-lactose has recently been analyzed by Visser and Bennema (68). The a- and (3-lactoses 4a and 4b are disaccharides composed of a galactose and an a- or (3-glucose moiety linked... 

FIG. 7. Maximum axial disintegrating pressure vs. disintegration time of dicatcium phosphate and lactose tablets containing 2% super disintegrants. (O) Dicalcium phosphate r = 0.92, p < 0.05, significant correlation (A) Lactose r = 0.81, p < 0.05, significant correlation. (Replotted from Ref. 27). 

The factors affecting the Maillard reaction include temperature, time, moisture content, concentration, pH, and nature of the reactants. - It has been shown that, out of 21 amino acids, glycine, lysine, tryptophan, and tyrosine provide the most intense browning when exposed to five saccharides, especially a-lactose. The Maillard reaction is also responsible for the decreased availability of lysine in proteinaceous foods. 

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