Fructose spectroscopic studies

The specific volumes and coefficients of refraction have been calculated for aqueous solutions of sucrose at several temperatures. Self-diffusion coefficients have been reported for sucrose, sodium D-glucuronate, and 2-amino-2-deoxy-D-glucose hydrochloride in aqueous solution. The triboluminescence (i.e. luminescence caused by mechanical stress) of crystalline mono- and di-saccharides has been studied this phenomenon was shown by some sugars (e.g. sucrose and D-glucose) but not by others (e.g. cellobiose and D-mannose). An e.s.r. spectroscopic study of D-glucose, D-mannose, D-galactose, D-fructose, and methyl... 

These are some examples of the use of i.r. spectra in the analysis and identification of carbohydrates in foods and natural products. Very often, these spectroscopic techniques are complementary to others, such as the study of aldobiouronic acids obtained by hydrolysis of peach-gum polysaccharides by their optical rotations and their i.r. spectra.100 However, the i.r. results appear to be sufficiently reliable to be used in the detection of traces of fructose and glucose, and to determine the d.e. (dextrose equivalent) of corn syrups, as well as the quantitative carbohydrate content in different products.101... 

The keto tautomer has been isolated in crystalline form for a number of D-fruc-tose-A -alkylanilines and the structure was unequivocally confirmed by IR and solid-state NMR spectroscopic data, " as well as by X-ray diffraction studies. " The ability of D-fructose-A -alkylanilines to crystallize spontaneously in the acyclic keto form is unprecedented among six-carbon reducing carbohydrates, and is matehed only by ribulos- and xylulos-amines, " which themselves are the Amadori rearrangement products. This phenomenon may be explained on the basis of an interplay of the hydrophobic effect and crystal-packing forces, given that many D-fruetose-A -alkylanilines still crystallize in the p-pyranose form, and for the majority of those which crystalhze in the keto form, the acyclic tautomer constitotes a minor eonstituent in equilibrated solutions. 

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