Plant gums monosaccharides

Polysaccharides are polymers made up of many monosaccharides joined together by glycoside bonds, and include cellulose, starch, vegetable mucilage and plant gums. 

V. Pitthard, P. Finch, GC MS analysis of monosaccharide mixtures as their diethyldithioacetal derivatives Application to plant gums used in art works, Chromatographia, 53, S317 S321 (2001). 

In chromatographic techniques, qualitative identitication of organic binders requires quantitication of species obtained from the original polymeric materials amino acids from proteins, fatty acids from drying oils, or monosaccharides in plant gums. 

Figure 5. Predominant monosaccharides found in plant gums shown in their a configurations.

C5H10O5, Mr 150.13. d-A. mp. 159-160°C, [a]n -175- -105° (H2O) l-A. mp. 160°C, [a]o +190- +105 (HjO). Monosaccharide of the aldopen-tose series. d-A. occurs only rarely in nature in bacterial polysaccharides. l-A. is frequently found in nature in plants, gums, hemicelluloses, pectins, bacterial polysaccharides, in the form of glycosides, glycocon-jugates, and heteropolysaccharides. l-A. is isolated from dried beet pulp. Aloe, and gums. ... 

Heteroglycans polysaccharides composed of two or more different monosaccharide residues, e.g. pectins, plant mucilages, plant gums and mucopolysaccharides. 

When a plant is wounded there often exudes from the opening a viscous, sticky fluid which tends to cover and seal the incision. On drying in air the fluid thickens and hardens to a brittle, translucent, glassy mass. These exu-udates, plant gums, are in deciduous plants, often composed of polysaccharides. They are practically always highly branched structures (D in Fig. 1) composed of two to five types of monosaccharides. Almost all exu-... 

Table 4.34 Basic monosaccharide composition of plant gums and mucilages (% w/w).

Interest in the genetic engineering of both plants and micro-organisms for the production of tailor made amylose, amylopectin and/or starches has also been reported. Furthermore, investigations on the enzymatic modification of starch and its major components, for example the introduction of additional branches composed of glucose and/or other monosaccharides and/or uronic acids as well as amino acids or peptides, to produce carbohydrates of possibly comparable functionality to galactomannans, pectin, gum arable, etc., has been initiated. Also studies on the metabolic fate of carbohydrates in food, the biosynthesis of starch, the fine structure of starch from different sources, the effect of electrolytes on the gelatinization of starch and the development of enzymic methods for starch analyses are still active. 

Polysaccharides are made from linking multiple monosaccharide units. These long chain molecules are known as starch in the plant system and glycogen in the animal system. Starch polysaccharides primarily contain a-glucans. These include amylose, amylopectin, modihed starches, and resistant starches. Fiber, also known as nonstarch polysaccharides (NSP), primarily contains components derived from the plant cell wall such as cellulose, hemiceUulose, and pectin. Other polysaccharides include gums and hydrocoUoids. 

The polysaccharides obtained from higher plants may be classified as homopolysaccharides (starch and cellulose) made up of a large number of monosaccharides of the same type, and heteropolysaccharides (mucilage, gum and pectin) made up of a large number of monosaccharides of different types. 

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