Molecular maltodextrins

Sutton [1.15] studied the question of how quickly solutions with certain CPAs (GL, dimethylsulfoxide (DMSO) and others] have to be cooled in order to avoid crystallization. At 100 °C/min concentration of 42.1 % DMSO and 48.5 % for GL are necessary to achieve the glass phase. With a 32.5 % solution of (2R.3R)-(-)butan-2,3-dio, the same effect can be accomplished at = 50 °C/min. In Fig. 1.18 Sutton (Fig. 11 from [1.114]) showed, that polyethylene glycol with a molecular weight of 400 (PEG 400) reduced the critical cooling rate down to approx. 25 °C/min. The addition of PEG 8000 [1.115] improved the protection of lactate dehydrogenase (LDH) by maltodextrins, if maltodextrins with low dextrose equivalents are used. 

Figure 6.10 Effect of CITREM on the molecular and thermodynamic parameters of maltodextrin SA-2 (DE = 2) in aqueous medium (phosphate buffer, pH = 7.2, ionic strength = 0.05 M 20 °C) (a) weight average molar mass, Mw (b) radius of gyration, Ra (c) structure sensitive parameter, p, characterizing die architecture of maltodextrin associates (d) second virial coefficient, A2 or A2, on the basis of the weight ( ) and molal (A) scales, respectively. The parameter R is defined as the molar ratio of surfactant to glucose monomer units in the polysaccharide. The indicated cmc value refers to the cmc of the pure CITREM solution. Reproduced from Anokhina et al. (2007) with permission.

Anokhina, M.S., Semenova, M.G., Belyakova, L.E., Polikarpov, Yu.N. (2007). The modification of the molecular and thermodynamic parameters of the low-DE potato maltodextrin in an aqueous medium through the interactions with anionic small-molecule surfactants. Food Hydrocolloids, 21, 693-703. 

This relative molecular size difference between starch and the hydrolysis sugars gives maltodextrins and corn syrup solids their valuable functional properties for the flavor industry. 

The advantage of using antibiotics, cyclodextrins, maltodextrins and fullerenes as chiral selectors is that the enantioselectivity of the molecular interaction takes place in two places inside the cavity (internal enantioselectivity) and outside the cavity—due to the arrangement, size and type of the radicals, atoms or ions bound on the external chain of the chiral selector (external enantioselectivity) [10]. The thermodynamics of the reaction between the enantiomers and chiral selectors plays the main role in the enantioselectivity of molecular interaction. 

Thermophilic archaeal a-amylases do not differ superficially from other a-amylases in their molecular size and amino acid composition. They are primarily monomeric enzymes with molecular weights of 40-70 kDa.84,88-90 Some of these amylases produce specific maltodextrin products, which are also summarized in Table 7.1. 

Improved stability towards oxidation of spray dried flavor oils was achieved by using a combination of a high-maltose syrup, maltodextrin and a high molecular weight, film-forming polysaccharide, such as starch octenylsuccinate or gum ara-bic.200 201 Emulsification performance of maltodextrins is improved by treatment with octenylsuccinic anhydride and aluminum sulfate. 

The maltose molecule is too small to be fitted conveniently into the molecular barrier hypothesis, but the receptor for this substance functions well with maltodextrins which do have higher molecular weights. The receptor is induced with maltose, a substrate which is doubtless commonly encountered in the diet of enteric bacteria. Biologically the receptor serves for transport of maltose and for chemotaxis to this substrate (72). The data presented in Table IV, especially that pertaining to the ferrichrome receptor, demonstrate convincingly that phage receptors were designed for nutritious substances. 

Maltodextrins of varying molecular weights are plasticized by water and decrease the glass transition temperature. Maltodextrins retard the crystallization of amorphous sucrose and at high concentrations totally inhibit sucrose crystallization (Roos and Karel 1991c). 

The effect of water and molecular weight on the glass transition has been shown on the state diagram for maltodextrins (Figure 7.5). Although T g and are observed individually with maltose (Figure 7.3), the difference between T g and T is... 

Figure 7.5. State diagram for maltodextrins (Reproduced with permission from Roos and Karel, 1991b, Water and molecular effects on glass transitions in amorphous carbohydrates and carbohydrate solutions, J. Food Sci. 56, pp. 1676-1681, Institute of Food Technologists.)...

Figure 7.6. Effect of molecular weight on the glass transition temperature of maltodextrins (Reprinted with permission from Roos and Karel, Phase transitions of mixtures of amorphous polysaccharides and sugars, Biotechnol. Progr. 7, pp. 49-53. Copyright (1991) American Chemical Society.)...

Grattard, N., Salaun, F., Champion, D., Roudaut, G., and Le Meste, M. (2002). Influence of physical state and molecular mobility of fieeze-dried maltodextrin matrices on the oxidation rate of encapsulated lipids. J. FoodSci. 67, 3002 3010. 

The unusual utility of this adsorbent has been demonstrated by its role in the preliminary isolation of isomaltose,maltotriose, maltotetra-086, = and panose > from the hydrolytic products of starch in the preparation of n-xylo-biose, -trio.se, -tetraose, -pentaose, -hexaose, and -heptaose from a partially hydrolyzed xylan in the resolution of bi-molecular dianhydrides of L-sorbose < and D-fructose < > in an improved procedure for the preparation of stachyose and in the preparation of a series of maltodextrins (as high as maltoheptaose) from the partial, acid... 

Icodextrin (rINN) is a maltodextrin glucose polymer with a mean molecular weight of 20kDa, which is broken down to maltose. It is used as an alternative to glucose as the active osmotic agent for peritoneal dialysis. Icodextrin is similar in structure to dextran, but has improved ultrafiltration properties, because it is less well absorbed than glucose. 

It is the amylose component of starch that gives the blue color when KI/I2 solution is added. To study the iodine-iodide color of amyloses of different d.p. values, maltodextrin-amylose molecules, with various avg. d.p. values from 6 to 568 were prepared by Bailey and Whelan [62], using phosphorylase, a-D-glucopyranosyl-1-phosphate, and maltohexaose. The colors of the various sized maltodextrins (1 mg) were observed when 10 1 (w/w) KI/I2 solution was added. The first color to be observed was faint red for avg. d.p. 12 a red-purple color was observed for avg. d.p. 31 a purple color was observed for avg. d.p. 40 and a blue color was observed for avg. d.p. 45. The increase in the blue value was linear as a function of avg. d.p. up to avg. d.p. 60 the absorbance at 645 nm then slowly increased and reached a maximum at avg. d.p. of 400. The intensity of the iodine/iodide color in the low molecular weight range was dependent on the concentration of the iodine. When the concentration of the iodine was increased 10-fold, the intensity was increased 50% [62]. 

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