Lactose properties

Rajah KK, Blenford DE, eds. The ALM Guide to Lactose Properties and Uses. The Hague The Association of Lactose Manufacturers, 1998. 

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. 

Uses of lactose production by appHcation include baby and infant formulations (30%), human food (30%), pharmaceuticals (25%), and fermentation and animal feed (15%) (39). It is used as a diluent in tablets and capsules to correct the balance between carbohydrate and proteins in cow-milk-based breast milk replacers, and to increase osmotic property or viscosity without adding excessive sweetness. It has also been used as a carrier for flavorings. 

Disaccharides like maltose, lactose, and trehalose are used for their similarity to sucrose, but with differences in some properties, such as sweetness, melting point, or hygroscopicity. 

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

X-ray diffraction studies are usually carried out at room temperature under ambient conditions. It is possible, however, to perform variable-temperature XPD, wherein powder patterns are obtained while the sample is heated or cooled. Such studies are invaluable for identifying thermally induced or subambient phase transitions. Variable-temperature XPD was used to study the solid state properties of lactose [20], Fawcett et al. have developed an instrument that permits simultaneous XPD and differential scanning calorimetry on the same sample [21], The instrument was used to characterize a compound that was capable of existing in two polymorphic forms, whose melting points were 146°C (form II) and 150°C (form I). Form II was heated, and x-ray powder patterns were obtained at room temperature, at 145°C (form II had just started to melt), and at 148°C (Fig. 2 one characteristic peak each of form I and form II are identified). The x-ray pattern obtained at 148°C revealed melting of form II but partial recrystallization of form I. When the sample was cooled to 110°C and reheated to 146°C, only crystalline form I was observed. Through these experiments, the authors established that melting of form II was accompanied by recrystallization of form I. 

Many surface area studies have investigated various properties of excipients. The relationship between excipient grades, flow properties, particle sizes, and surface areas have been studied. Fast-flo lactose is manufactured to contain larger particles (approximately 50 jim) than hydrous lactose (approximately 20 /zm) [23], This has been done to improve the flow properties of the fast-flo... 

The range of application of shear cell testing methodology is seen in Tables 2-6. Table 3 relates the flow properties of mixtures of spray-dried lactose and bolted lactose. These mixtures, in combination with the excipients tested, cover a broad range of flow. Tables 4 and 5, for example, show lot to lot variations in the flow properties of several materials, and Table 6 shows the variation in flow properties of bolted starch, sucrose, and phenacetin at different relative humidities (RH). Figure 8 presents the yield loci of sucrose at four different consolidation loads. Also shown in the figure are the shear indices determined at each consolidation load. 

Table 10 Properties of Compacts of Mixtures of Spray-Dried Lactose and Sucrose...

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. 

Lactose, trehalose and maltose have equally lyoprotectant properties, while liposomes with sucrose showed an increase in size. 

Field Pea Flour in Other Baked Products. When McWatters (44) substituted 8% field pea flour and 4.6% field pea concentrate for milk protein (6%) in baking powder biscuits, sensory attributes, crumb color, and density of the resulting biscuits were adversely affected. No modifications were made in recipe formulation when pea products were incorporated. The doughs were slightly less sticky than control biscuits that contained whole milk. This might be due to lack of lactose or to the different water absorption properties of pea protein or starch. Panelists described the aroma and flavor of these biscuits as harsh, beany and strong. Steam heating the field pea flour improved the sensory evaluation scores, but they were never equivalent to those for the controls. 

Zhou, Q., Armstrong, B., Larson, I., Stewart, P. J., Morton, D. A. V. Improving powder flow properties of a cohesive lactose monohydrate powder by intensive mechanical dry coating. J. Pharm. Sci., 99, 2010, 969-981. 

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