Matrix carbohydrates, polysaccharides

The effects of water on the destruction of the protective food structure in some specific dehydrated foods is probably involved in prevention of lipid oxidation in heated meat systems (Karel, 1986). In systems in which there are both surface lipids and lipids encapsulated within a carbohydrate, polysaccharide, or protein matrix, the surface lipids oxidize readily when exposed to air. The encapsulated lipids, however, do not oxidize until the structure of the encapsulated matrix is modified and/or destroyed by adsorption of water as shown by Simatos and Karel (1988). In some IM meats, muscle may be considered as being encased in or surrounded by a humectant matrix. However, free lipid may be left on the surfaces. The unwarranted overuse of lipids, which often happens in the indirect drying process to improve heat transfer and to prevent burning, is detrimental to the products. Prevention of this structural change is of considerable... 

Besides water, the diet must provide metabolic fuels (mainly carbohydrates and lipids), protein (for growth and turnover of tissue proteins), fiber (for roughage), minerals (elements with specific metabolic functions), and vitamins and essential fatty acids (organic compounds needed in small amounts for essential metabolic and physiologic functions). The polysaccharides, tri-acylglycerols, and proteins that make up the bulk of the diet must be hydrolyzed to their constituent monosaccharides, fatty acids, and amino acids, respectively, before absorption and utilization. Minerals and vitamins must be released from the complex matrix of food before they can be absorbed and utifized. 

Three types of carbohydrate sample have been reported to give data above mass 4000, namely, permethylated polysaccharides, permethylated glycosphingolipids, and naturally acylated forms of a mycobacterial O-methyl-D-glucose polysaccharide. All are hydrophobic, and desorption is probably facilitated by their inability to form strongly hydrogen-bonded aggregates, either with themselves or with the matrix. 

The microorganisms in sewer biofilms are embedded in a matrix of EPS that consists mostly of polysaccharides produced by the bacteria (Characklis and Marshall, 1990). The EPS fraction is the largest organic fraction in the biofilm, i.e., up to about 90% of the total organic content. Only limited studies of the total composition of sewer biofilms in terms of carbohydrates, proteins and humic substances have been undertaken (Figure 3.12). Corresponding information on the composition of anaerobic biofilms in pressure mains does not yet exist. 

Vardi A, Formiggini F, Casotti R, De Martino A, Ribalet F, Miralto A, Bowler C (2006) A stress surveillance system based on calcium and nitric oxide in marine diatoms. PLoS Biol 4 411 119 Vorwerk S, Somerville S, Somerville C (2004) The role of plant cell wall polysaccharide composition in disease resistance. Trends Plant Sci 9 203-209 Vreeland V, Laetsch WM (1990) A gelling carbohydrate in algal cell wall formation. In Adair WS, Mecham RP (eds) Organization and assembly of plant and animal extracellular matrix. Academic, San Diego, CA, ppl 37—171... 

Armstrong attributed the increased resistance of dentin matrix to proteolysis to the blockage of susceptible sites by covalently bound carbohydrate. Later it became clear that the Maillard reaction induces the formation of covalent bonds (cross-links) between protein molecules, accounting for such resistance as well. The presence of non-degradable matrix proteins inhibits mineral dissolution (Chapter 2). In addition, both brown pigments and cross-linked proteins inhibit the production of extracellular polysaccharides by cariogenic streptococci (Kobayashi et al., 1990). 

In addition to their important roles as stored fuels (starch, glycogen, dextran) and as structural materials (cellulose, chitin, peptidoglycans), polysaccharides and oligosaccharides are information carriers they serve as destination labels for some proteins and as mediators of specific cell-cell interactions and interactions between cells and the extracellular matrix. Specific carbohydrate-containing molecules act in cell-cell recognition and... 

One of the important fields where carbohydrate polymer/inorganic hybrids may be successfully applied is bioactive materials, e.g., artificial bones expedient for surgery to accelerate the recovery of living bones. There has been increasing interest in hydroxyapatite (HAp) deposition onto the matrix surface of cellulose or related polysaccharide. HAp is a form of calcium phosphate, a main constituent of the inorganic phase of human bone. This kind of study is also a step on the way to exploitation of new biomimetic mineralization methods. 

M. K. Fatema, H. Nonami, D. R. B. Ducatti, A. G. Gonqalves, M. E. R. Duarte, M. D. Noseda, A. S. Cerezo, R. Erra-Balsells, and M. C. Matulewicz, Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of oligosaccharides and oligosaccharide alditols obtained by hydrolysis of agaroses and carrageenans, two important types of red seaweed polysaccharides, Carbohydr. Res., 345 (2010) 275-283. 

Proteoglycans resemble polysaccharides more than proteins in as much as the carbohydrate makes up as much as 95% of the hiomolecule hy weight. Proteoglycans function as lubricants and structural components in connective tissue, mediate adhesion of cells to the extracellular matrix, and bind factors that stimulate cell proliferation. 

Higher oligosaccharides or polysaccharides possess unfavorable mass-to-charge ratios, preventing their effective resolution in open tubes. The separation of these carbohydrates is possible with capillary gel electrophoresis (CGE). The analytes are selectively retarded by a sieving network (gel or polymer matrix) due to differences in their sizes and structural conformations. 

Carbohydrates and fatty acids are also necessary for rapid and good-quality skin regeneration. The extracellular matrix is made up of glycosaminoglycans and proteoglycans, which are polysaccharides linked to proteins. Omega-6 fatty acids are essential for cell membrane formation. Supplements of linoleic and linolenic acid can be recommended when the patient s blood is not properly balanced. ... 

Confectioneries, such as molasses and other sugar products, may be diluted with water or aqueous buffer prior to SPE. Chocolate, which has a high fat content, will need extraction with hexane or methylene chloride to remove the fat then an aqueous solvent or polar solvent such as methanol may be used to extract the carbohydrate or polysaccharide. The choice of sorbents to recover specific analytes from this matrix would be reversed phase, such as C-8 or C-18. 

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