Carbohydrates fractionation

Although the total content of carbohydrate fractions of the three components is similar, as reported by Williams et al., 1990, it was found that protein-rich fractions have a significantly lower glucuronic acid content. Circular dichroism studies conducted on different GA fractions showed that only the AGP and GP components have a secondary structure (Renard et al., 2006). The AGP fraction was isolated by gel filtration chromatography and subjected to deglycosylation with hydrofluoric acid (HF) to separate the protein (Qi et al., 1991). About 400 amino acids were contained by the AGP protein fraction ( 33% are... 

GA is well recognized as emulsifier used in essential oil and flavor industries. Randall et al., 1998, reported that the AGP complex is the main component responsible for GA ability to stabilize emulsions, by the association of the AGP amphiphilic protein component with the surface of oil droplets, while the hydrophilic carbohydrate fraction is oriented toward the aqueous phase, preventing aggregation of the droplets by electrostatic repulsion. However, only 1-2% of the gum is absorbed into the oil-water interface and participates in the emulsification thus, over 12% of GA content is required to stabilize emulsions with 20%... 

Gopal, N. H., Venkataramanan, D., Effect of ethrel on carbohydrate fractions of Coffea arabica L. fruits, Turrialba. 27, 101, 1977. (CA87 97235n)... 

The effect of chemical delignification on the carbohydrate fraction is predominantly that of pH, and it is important therefore to consider separately degradation in alkali and in acidic pulping systems. 

Both in the USA and the EU, the introduction of renewable fuels standards is likely to increase considerably the consumption of bioethanol. Lignocelluloses from agricultural and forest industry residues and/or the carbohydrate fraction of municipal solid waste (MSW) will be the future source of biomass, but starch-rich sources such as corn grain (the major raw material for ethanol in USA) and sugar cane (in Brazil) are currently used. Although land devoted to fuel could reduce land available for food production, this is at present not a serious problem, but could become progressively more important with increasing use of bioethanol. For this reason, it is important to utilize other crops that could be cultivated in unused land (an important social factor to preserve rural populations) and, especially, start to use cellulose-based feedstocks and waste materials as raw material. 

M. Mecozzi and Zs. Papai, Application of curve fitting thin-layer chromatography-flame ionization detection analysis of the carbohydrate fraction in marine mucilage and marine snow samples from Italian seas. J. Chromatogr. Sci. 42 (2004) 268-274. 

Elforts have been made to characterize the nature and content of individual components that are present in the low-molecular-mass fraction of the total mill effluents, which include the spent chlorination and alkali extraction stage liquors [2,4]. Approximately 456 types of compounds have been detected in the conventional bleach effluents, of which 330 are chlorinated organic compounds [22]. The compounds may be lumped into three main groups, namely, acidic, phenolic, and neutral (Table 2). Acidic compounds are further divided into the five categories of acids fatty, resin, hydroxy, dibasic, and aromatic acids. The most important fatty acids are formic and acetic acids. The dominant resin acids are abietic and dehydroabietic acids. Among the hydroxy acids identified, glyceric acid predominates. Dibasic acids such as oxalic, malonic, succinic, and mafic acids are derived from the lignin and carbohydrate fraction... 

What is known for a long-time lipids are depleted in by 5-8%o relative to the bulk biomass. Recently, Teece and Fogel (2007) demonstrated that the carbohydrate fraction of various organisms on average is enriched in by 4.6%c relative to the bulk. Even larger variations are observed for individual amino acids (Abelson... 

The development of chemical, physical, and enzymic methods for investigating the primary structure of the carbohydrate fractions of glycoconjugates has, during the past ten years, allowed the determination of the structures of numerous glycans. In this regard, the combination of the techniques of permethylation and 360-MHz, proton-n.m.r. spectroscopy has afforded real progress in the rapid determination of the primary structures of oligosaccharide chains. 

Figure 18.18. Standard differential scanning calorimetry scan of Georgetown carbohydrate fraction indicating multiple transitions 7) near -23 °C and T-, near 41 °C. Reproduced from DeLapp et al. (2005), by permission of the Soil Science Society of America.

Heating the diffusate in water produced an odor reminiscent of roast beef broth. The diffusate could be separated into amino acid and carbohydrate fractions by ion exchange chromatography and neither produced a meaty odor upon heating, but recombining the subfractions produced a mixture with a "beef-like" odor upon heating. 

Hemicellulose Group of carbohydrates found in the cell wall in more or less intimate contact with cellulose. The hemicelluloses are more soluble than cellulose and much more readily hydrolyzed into sugars. Holocellulose Total carbohydrate fraction of wood remaining after the removal of lignin and solvent extractable substances. 

In these copolymers, the saccharide block is a carbohydrate fraction (0Q or Op) of a glycoprotein (ovomucoid) and the peptide block is a poly(benzyl-L-glutamate) block or a poly(cinnamyl-L-glutamate) block. 

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