Polysaccharide importance, industrial

The editorial policy of the publication will continue in its past form. To quote from Volume I It is our plan to have the individual contributors furnish critical, integrating reviews rather than mere literature surveys, and to have the articles presented in such a form as to be intelligible to the average chemist rather than only to the specialist. Invitations will be extended to selected research workers to prepare critical reviews of special topics in the broad field of the carbohydrates, including the sugars, polysaccharides and glycosides. It is also the intention to include biochemical and analytical developments in the carbohydrate field as well as critical reviews of important industrial advances. 

Polysaccharides were the first group of polymers considered. Dextrans, polymers of glucose synthesized from sucrose, are Important Industrial polysaccharides ( ) ... 

Much of the earlier work on selective reactivity was motivated by the preparation and study of polysaccharides of industrial importance. It appears that more effort may have been exerted in this field than in that of monomeric chemistry. 

There are many kinds of natural biodegradable polymers. They are classified into three types according to their chemical structures, i.e., polysaccharides, polypeptides/proteins and polynucleotides/nucleic acids. Among them, polysaccharides, such as cellulose, chitin/chitosan, hyaluronic acid and starch, and proteins, such as silk, wool, poly( y-glutamic acid), and poly(e-lysin), are well known and particularly important industrial polymeric materials. 

An important group of enzymatically derived polymers is polyesters. In nature, they hold the fourth place after the three major biomacromolecules (nucleic acids, proteins, and polysaccharides). Important polyesters are poly(ethylene terephthalate) (PET), poly(butylene succinate) (PBS), poly(e-caprolactone) (poly(e-CL)), and poly(lactic acid) (PLA) (see Fig. 3.40). The former two are industrially produced via polycondensation and the latter two via ROP. Additionally, enzymes can be used to hydrolyze ester bonds, which offers the possibility to recycle commercially used materials, for example, PET [52]. 

Notwithstanding the chemical differences (alcohol groups in guaran, carboxyl groups in xanthan, and partially esterified carboxyl groups in pectin) these three polysaccharides in combination with chitosan in the microspheres appear to be able to bring chitosan into solution. This is particularly interesting if one considers the solubility of these three polysaccharides in water and their important applications in the food and pharmaceutical industries. 

The objective of the project described is to obtain insight in the relation between the chemical fine-structure of polysaccharides from soy bean cell walls and their functional properties in industrial products and how they effect processing. Soy meal is of great importance in the feed industry. The application of the (modified) soy bean cell wall polysaccharides as a food additive will be investigated. The obtained knowledge of the polysaccharide structures will also be used in studies concerned with the improvement of the in vivo digestibility of these polysaccharides. 

Dextran is the first microbial polysaccharide produced and utilized on an industrial scale. The potential importance of dextran as a structually (and property) controlled feedstock is clearly seen in light of the recent emphasis of molecular biologists and molecular engineers in the generation of microbes for feedstock production. Dextran is employed as pharmaceuticals (additives and coatings of medications), within cosmetics, as food extenders, as water-loss inhibitors in oilwell drilling muds and as the basis for a number of synthetic resins. 

In both their industrial and biological functions, the 3-dimensional characteristics of carbohydrates are important. Many of these stereochemical features are described for carbohydrates in the classic text by Stoddart (2). The inqportance of stereochemistry is underscored by the unique chemical and physical properties of the individual sugars, many of which are configurational isomers. Stereochemistry also plays a role in detentlining the properties of polysaccharides. Molecular shape is as significant for the properties of an industrially modified starch as it is for the recognition of one particular blood type and the rejection of others. 

GELLAN. The extracellular, anionic, linear polysaccharide from Pseudomonas elodea, is called gellan in its deacylated form. It is industrially important because of its ability to form cation-dependent gels. Its tetrasaccharide repeating motif (A-B-C-D) is given below ... 

Another potentially important fermentation is that producing butyric acid. The process is used industrially on only a small scale at present and details have not been disclosed. Many derivatives of butyric acid are used industrially the benzyl, methyl, octyl and terpenyl esters are used in the perfumery and essence trade and amyl butyrate, bornyl and isobornyl butyrates have been described as plasticizers for cellulose esters. Moreover vinyl butyrate is a possible ingredient of polymerizable materials. The mixed acetic and butyric acid esters of polysaccharides are also coming into favor. Cellulose acetate butyrate is marketed as an ingredient of lacquer and is less inflammable than the pure acetate. Dextran (see below) acetate butyrate may have similar uses. 

The bulk of potato tubers is made up of parenchyma cells that have thin, non-lignified, primary cell walls (Reeve et al., 1971 Bush et al, 1999, 2001 Parker et al., 2001). Unless stated to the contrary, potato cell walls refers to parenchyma cell walls. These walls and their component polysaccharides are important for a number of reasons they form part of the total intake of dietary fiber, influence the texture of cooked potato tubers and form much of the waste pulp that is produced in large amounts by the potato starch industry when starch is isolated. The pulp is usually used as cattle feed, but potentially could be processed in a variety of ways to increase its value (Mayer, 1998). For example, the whole cell-wall residues could be used as afood ingredient to alter food texture and to increase its dietary-fiber content, or cell-wall polysaccharides could be extracted and used in a similar way or for various industrial applications (Turquois et al., 1999 Dufresne et al, 2000 Harris and Smith, 2006 Kaack et al., 2006). 

In addition to being necessary for all forms of life, biopolymers, especially enzymes (proteins), have found commercial applications in various analytical techniques (see Automated instrumentation, clinical chemistry Automated instrumentation, hemtatology Biopolymers, analytical techniques Biosensors Immunoassay) in synthetic processes (see Enzyme applications, industrial Enzyme applications in organic synthesis) and in prescribed therapies (see Enzyme applications, THERAPEUTICS IMMUNOTHERAPEUTIC AGENTS Vitamins). Other naturally occurring biopolymers having significant commercial importance are the cellulose (qv) derivatives, eg, cotton (qv) and wood (qv), which are complex polysaccharides. 

Introduction. Today nitrocellulose is one of most important derivatives of cellulose used in industry and commerce, and a major product of the chemical industry. Its wide and manifold applications are due mainly to its extraordinary physical properties. Thus a protective coating of nitrocellulose varnish, a nitrocellulose film or a tube of smokeless powder — all are characterized by relatively high elasticity and mechanical strength. These properties are a direct consequence of the microstructure of cellulose, which is composed of highly oriented long-chain molecules of polysaccharide. Not only nitrocellulose, but also other derivatives of cellulose, such as other esters and ethers, demonstrate similar characteristics. 

This subject has been of continuing interest for several reasons. First, the present concepts of the chemical constitution of such important biopolymers as cellulose, amylose, and chitin can be confirmed by their adequate chemical synthesis. Second, synthetic polysaccharides of defined structure can be used to study the action pattern of enzymes, the induction and reaction of antibodies, and the effect of structure on biological activity in the interaction of proteins, nucleic acids, and lipides with polyhydroxylic macromolecules. Third, it is anticipated that synthetic polysaccharides of known structure and molecular size will provide ideal systems for the correlation of chemical and physical properties with chemical constitution and macromolecular conformation. Finally, synthetic polysaccharides and their derivatives should furnish a large variety of potentially useful materials whose properties can be widely varied these substances may find new applications in biology, medicine, and industry. 

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