Galactomannan properties

Khan MAS, et al. Molecular mechanism of the excellent emulsifying properties of phos-vitin-galactomannan conjugate. J Agric Food Chem 1999 47(6) 2262 2266. 

In describing and interpreting some of the more important properties of plant galactomannans, comparisons will be made with structurally similar polysaccharides, including the closely related glucomannans and galactoglucomannans, and those based on (1 — 4)-/3-D-xylan main-chains (for example, the arabinoxylans) and (1 — 4)-/3-D-glucan main-chains [for example, the amyloids and sodium 0-(carboxymethyl)cellulose]. 

Two fundamental properties determine much of the behavior of polymers the molecular weight and the conformation (molecular shape). Because of the very high viscosities of even dilute solutions of galactomannans, determinations of the molecular weight are technically difficult. 

The patent literature pertaining to the industrial exploitation of guar gum from 1948 to 1962 has been comprehensively collated by Saxena,34 and will not be considered here. Saxena s compilation34 covers more than 70 patents relating to 15 industries, and includes gum extraction and purification, and modification of gum properties. A selection, taken from the literature over the past decade or so, of applications of galactomannans is given in Table VI. It may be seen that guar gum is, indeed, a versatile product. Some of the more im-... 

The chemical and physical properties of the galactomannans are important in their industrial applications. Thus, the ability to imbibe water, to form a thick, mucilaginous paste that is impervious to further water, is utilized by the mining and related industries, both as a method of waterproofing explosives236-258 and as a plugging composi-... 

The linear, but highly branched, molecular structure of the galactomannans is the reason for some specific properties which are quite different from those of the unbranched cellulose-like and water-insoluble mannans and glucomannans. Galactomannans are hydrated in cold water and give stable solutions even in acidic formulas. The interactions of galactomannans with other polysaccharides are the base of a variety of industrial applications. 

Two articles12,423 have been published that discuss the structure, properties, and biochemistry of D-galactomannans. In addition, several other reviews on this group of polysaccharides are available.1,424-428 In this Section, an overall description of D-galactomannans will be given, with inclusion of recent advances made in this field. 

N. Matsudomi, K. Nakano, A. Soma, and Ochi, A. Improvement of gel properties of dried egg white by modification with galactomannan through Maillard reaction, J. Agric. Food Chem., 2002, 50, 4113-4118. 

Doublier, J.-L., and Llamas, G. (1991). Flow and viscoelastic properties of mixed xanthan gum + galactomannan systems. In Food Polymers, Gels and Colloids, Dickinson, E. (Ed.), pp. 349-356. Royal Chem. Soc., London. 

Hui, P. A., and Neukom, H. (1964). Some properties of galactomannans. Tech. Assoc. Pulp and Paper Indus. 47 39-42. 

Robinson, G., Ross-Murphy, S. B., and Morris, E. R. (1982). Viscosity-molecular weight relationships, intrinsic chain flexibility, and dynamic solution properties of guar galactomannan. Carbohydr. Res. 107 17-32. 

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