Maltodextrins, complexation

Table 14.1 Maltodextrin complexes with the transport protein of maltose (from Quiocho 1989) (reproduced with kind permission from the International Union of Pure and Applied Chemistry). K

A similar protocol was used in novel complexes of different solid forms of Furosemide (I and II) with maltodextrin or pCD in [37,105]. Remarkable examples were the furosemide—maltodextrin complexes, where it was not possible to characterize them by spectroscopic methods. Taking into... 

The presence of a thermodynamically favourable interaction between protein and polysaccharide is commonly associated with a marked decrease in protein surface activity at the air-water or oil-water interface (see Figures 7.5b and 7.15). There is a slower decay in the surface tension for complexes in comparison with the pure protein, and also higher values of the tension in the steady state. Data establishing these trends have been reported for the following biopolymer pairs in aqueous media legumin + dextran and legumin + maltodextrin (Antipova and Semenova,... 

The main components of the membrane of the enantioselective, potentiometric electrode are chiral selector and matrix. Selection of the chiral selector may be done accordingly with the stability of the complex formed between the enantiomer and chiral selector on certain medium conditions, e.g., when a certain matrix is used or at a certain pH. Accordingly, a combined multivariate regression and neural networks are proposed for the selection of the best chiral selector for the determination of an enantiomer [17]. The most utilized chiral selectors for EPME construction include crown ethers [18-21], cyclodextrins [22-35], maltodextrins 136-421, antibiotics [43-50] and fullerenes [51,52], The response characteristics of these sensors as well as their enantioselectivity are correlated with the type of matrix used for sensors construction. 

The action of chlorine in alkaline media is much slower than that of bromine. Lewin29 reported that the rate of oxidation of D-glucose at pH 9.8 by hypobromite is 1360 times higher than that by hypochlorite at the same pH. For cellulose, the ratio is much smaller (33 to 1). The complexity of the latter system is, however, revealed by the variability of this ratio over the pH range of 8-13 at pH 6-7, the action of hypochlorite is actually slightly faster than that of hypobromite. Maltodextrins and starch have been oxidized with alkaline sodium hypochlorite. The resulting oxidized polysaccharide formed stable complexes with calcium cations.30... 

M. Floor, A. P. G. Kieboom, and H. van Bekkum, Preparation and calcium complexation of oxidized polysaccharides. 1. Oxidation of maltodextrin and starch with alkaline sodium-hypochlorite, Starch-Starke, 41 (1989) 348-354. 

Duan, X., Hall, J. A., Nikaido, H., and Quiocho, F. A. (2001). Crystal structures of the maltodextrin/maltose-binding protein complexed with reduced oligosaccharides Flexibility of tertiary structure and ligand binding./. Mol. Biol. 306, 1115-1126. 

Many interactions are of a pure chemical nature and may result from the presence of aldehydes and their reactivity toward amino and thiol groups of proteins. Another frequently occurring type of interaction is the formation of hydrogen bonds between food compounds and polar flavor components such as alcohols. Starch, starch-derived maltodextrins, and (3-cyclodextrin are able to form inclusion complexes with many flavor components. Many other interactions, although of great influence on flavor perception, are of a physical nature and therefore not mentioned in this chapter. 

A rather widespread family of proteins, found in the periplasmic space of gramnegative bacteria, complexes certain small molecules and allows them to be transported through the cell wall or activate chemotaxis. Each of these functions involves a consecutive interaction with specific membrane proteins. The molecules transported are amino acids, sulfate, mono- and oligosaccchrides. In this way ABP complexes L-arabinose (K 0.98 x 10 M), and MBP (maltodextrin-binding protein) complexes maltose (ATj 35 x 10 M) and maltodextrins. It is in this series that are found the strongest possible bonds between sugars and proteins. The dissociation rate ( i 1.5 s ) is indicative of the upper limit of the ionic transport rate. Hydrogen bonds... 

The transport protein which we have just described complexes an entire family of maltodextrins. The thermodynamic and kinetic parameters are shown in Table 14.1. It is remarkable that there are so few variations from maltose to cyclodextrins. The first three complexes in the table were obtained in the crystalline state. 

Specificity is a property of monocomponent systems and it occurs when the method is free of interference. Selectivity is related to the complexity of the matrix and it occurs when not more than one ion (molecule) interferes in determination. Enantioselectivity is a relatively new term introduced for the assay of enantiomers.257258 An analytical method is enantioselective when it can discriminate between enantiomers. Enantiospecificity is an extreme case of enantioselectivity. It is possible to create the conditions for a highly enantioselective analysis, and in this case enantiospecificity can also occur. For example, a maltodextrin with dextrose equivalence (DE) of 4.0 to 7.0 was used in capillary zone electrophoresis as a stationary phase for the separation of the enantiomers,259 and also in the design of a potentiometric, enantioselective membrane electrode.260 The method for capillary zone electrophoresis is enantioselective, as it is for the potentiometric method. 

Carmine is achieved by the complexing of cochineal extract with calcimn and aluminium. It can be standardised with maltodextrin or lactose and sold as carmine lake products of different concentrations and different shades of pink through red and violet to blue. Carmine is insoluble in water and acids, but soluble in alkali. By dissolving carmine lake in aqueous potassium, sodium and ammonium hydroxide, water-soluble powders and solutions can be made. Carmine has high colour intensity and is therefore more cost-effective than cochineal extract. 

Cyclodextrin glycosyllransferases [EC 2.4.1.19] share family 13 with alpha-amylases, although the latter are formally classed as hydrolases [EC 3.2.1.1], The CGTases utilize starch, maltodextrins, and a-maltosyl fluoride to synthesize cyclic compounds of six, seven, or eight a-(l -a 4)-linked glu-copyranose units as well as related noncyclic dextrins. The Bacillus circulans strain 251 enzyme complexed with acarbose shows an active-site structure... 

All industrial biotechnological production processes use complex cultivation media which consist of agricultural by-products (beet or cane molasses, corn-steep liquor, cottonseed meal, whey permeate, peanut floiu-, soybean meal, distillation residues, etc.). In addition polysaccharides (starch, dextrose, malt extract, maltodextrins, etc.) and proteins (e.g. caseinate, yeast autolysates, etc.) are used as energy sources for the microorganisms and cells. These systems... 

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