Industrial Utilization of Polysaccharides
Polysaccharides (excluding starch and its derivatives) are used commercially (for food and cosmetics and industrially) in their natural or modified state. The usefulness of most commercial polysaccharides is based on their capacity to alter the basic properties of water. In addition, polysaccharides have related secondary functions, such as emulsification, suspension, stabilization, encapsulation, flocculation, film forming, binding, and coating. Polysaccharides also play important roles in controlling the texture of foods as well as their flavour, appearance, and color. Polysaccharides have numerous functions in consumer products from increasing viscosity in food products to preventing the redeposition of soil in detergents. Subsequently, the solubility of polysaccharides in cold water is an important commercial property. Because of the wide range of functional characteristics exhibited by polysaccharides and the variations in operating and process conditions encountered, the combinations of polysaccharides are often used to obtain a desired functionality. Polysaccharides, both natural gums and derivatives, are classified as speciality chemicals as opposed to commodity chemicals. They are used as thickening and sizing agents in industrial applications.[1]
Bacterial Polysaccharides
This chapter discusses bacterial polysaccharides. The bacterial polysaccharides make up a group of polymers in which the structural variation is almost unlimited, and unusual sugars are often the components of these polymers. Some bacterial polysaccharides are commercially important and produced industrially. Most of the bacterial polysaccharides are antigenic and some are used as vaccines. A majority of the bacterial polysaccharides show high immunological specificity and are produced by only one type, one species, or one group of bacteria. These polysaccharides are generally composed of oligosaccharide repeating units. Other bacterial polysaccharides do not show this specificity but may be elaborated by bacteria belonging to different groups or families. In addition to the polysaccharides proper, bacteria also produce other polymers in which carbohydrates are main components. Also a considerable number of monosaccharides have been identified as the components of bacterial polysaccharides and the number is increasing. Bacterial classification is complicated and is frequently changed. Lastly, even if structures have been assigned to only a small number of the bacterial polysaccharides, it nevertheless seems possible to make some generalizations concerning the frequency of different structural elements. [2]
Other Plant Polysaccharides
This chapter discusses important sources of polysaccharides and their molecular constitutions. Two associated plant polysaccharides are the D-fructo-furanans and β-D-glucans containing mixed linkages. The association of lignin with polysaccharides through chemical linkages as well as in the form of physical incrustation is of profound economic importance in relation to the digestion of feedstuffs by ruminants and the exploitation of carbohydrate resources through enzymatic breakdown. Pectic substances or pectins have long been considered to include diverse types of polysaccharide structure based on appropriately linked units of D-galacturonic acid, D-galactose, and L-arabinose and are, like the hemicelluloses, of great economic importance. The capacity of a plant to assemble numerous sugar residues in an orderly matter must in some measure reflect certain genetic characteristics of the species concerned. The relationships of the hemicelluloses and pectic substances in primary cell walls to the polysaccharides available in abundance from tissues in developed, mature plant stuffs are interesting because the same economy of use of relatively few sugars linked in a limited number of ways is observed throughout. The presence or absence of minor structural features in a purified, homogeneous (or at least not demonstrably heterogeneous) polysaccharide preparation is of limited significance in the cases in which the isolation of the polysaccharide requires lengthy and involves physical and chemical extraction procedures.[3]
Hypoglycemic Potential of Polysaccharides of the Leaf Extract of Telfairia occidentalis
Context: Telfairia occidentalis Hook (Cucurbitaceae), a popular vegetable in West Africa, has been reported to have antidiabetic property. But the active components are not yet known.
Aims: This study was carried out to determine the hypoglycemic potentials and the antidiabetic property of polysaccharides of the leaf of Telfairia occidentalis.
Place and Duration of Study: Hypertension and Cardiovascular Physiology Research Laboratory; School of Pharmaceutical Sciences, University Sains Malaysia, Penang, Malaysia, between June 2013 and October 2013.
Methodology: The dried plant material was macerated with water and extracted with ethyl acetate to obtain ethyl acetate and aqueous residue fractions. To obtain the crude polysaccharides, the plant material was boiled with water. Ethanol (96%) was added to the extract. The precipitate obtained was successively washed with ethanol (99%), ether and acetone. Crude proteins were obtained by ammonium sulphate precipitation. The various fractions (250 and 500mg/kg) were orally administered to normoglycemic and STZ-induced diabetic rats. Blood glucose was evaluated with a glucometer at 0, 1, 2 and 4 hours, after administration. Glibenclamide (4mg/kg) was used as the positive control. Column chromatography and HPLC analyses of the aqueous residue and crude polysaccharides were carried out.
Results: None of the fractions at the two dose levels affected blood glucose concentration of the normoglycemic rats. However, the aqueous residue and crude polysaccharides significantly (p=0.05) reduced glucose level at 4 hours in the diabetic rats from 100% at 0 hour to 74.28 and 60.87% at 4 hours, respectively. Based on the column chromatography and HPLC profiles, the hypoglycemic activity of the aqueous residue and crude polysaccharides fractions could be attributed to their carbohydrates content.
Conclusion: Polysaccharides from the leaf of Telfairia occidentalis possess hypoglycemic activity and have the potential of being useful in the management of diabetes. Further work needs to be done to characterize the active polysaccharides.[4]
Characterization of Organic Manures for Polysaccharides, Microbial Biomass and Humic Substances
Soil organic matter (SOM) is an important indicator of soil quality as it determines many soil characteristics such as nutrient mineralization, structural stability and water holding capacity. An understanding of different bio-chemical processes undergoing inside the conventional sources of organic matter, which are used for farm management regarding improvement of soil structure which rely on organic carbon input as organic carbon is the main binding force between soil particles. Farm yard manure (FYM), poultry litter (PL) and municipal solid waste compost (MSWC) were characterized in an incubation experiment for six months in a completely randomized design (CRD). This study was carried out in 2011 at Department of Soil Science and SWC, PMAS Arid Agriculture University, Rawalpindi. Organic matter fractionation, total organic carbon (TOC), total polysaccharide content (TPC) and microbial biomass carbon (MBC) were determined. Results showed that PL has significantly highest values for all of the parameters except humic acid as compared to other manures. Results showed that TOC, MBC and humic acid decreased, fulvic acid remained unchanged and TPC increased significantly with incubation period. Interaction of manures and days showed that PL at 180 days had significantly highest contents of TOC and TPC. MBC content and humic acid were significantly highest at 0 and 30 days, respectively. Fulvic acid was highest at 30, 120, 150 and 180 days in PL. Correlation analysis showed that TPC was positively and significantly correlated with fulvic acid (0.732), TOC was negatively correlated with humic acid (-0.295) and positively correlated with MBC (0.668). These results suggested that the PL was better among other manures under study regarding TOC, TPC and MBC.[5]
Reference
[1] Sandford, P.A. and Baird, J., 1983. Industrial utilization of polysaccharides. In The polysaccharides (pp. 411-490). Academic Press.
[2] KENNE, L. and Lindberg, B.E.N.G.T., 1983. Bacterial polysaccharides. In The polysaccharides (pp. 287-363). Academic Press.
[3] Stephen, A.M., 1983. Other plant polysaccharides. In The polysaccharides (pp. 97-193). Academic Press.
[4] Eseyin, O.A., Sattar, M.A., Rathore, H.A., Ahmad, A., Afzal, S., Lazhari, M., Ahmad, F. and Akhtar, S., 2014. Hypoglycemic potential of polysaccharides of the leaf extract of Telfairia occidentalis. Annual Research & Review in Biology, pp.1813-1826.
[5] Bashir, K., Ali, S. and Ijaz, S.S., 2015. Characterization of organic manures for polysaccharides, microbial biomass and humic substances. Journal of Experimental Agriculture International, pp.532-539.
