Sugar-alcohol determination

Polarimetric analysis of sorbitol and mannitol in the presence of each other and of sugars is possible because of their enhanced optical rotation when molybdate complexes are formed and the higher rotation of the mannitol molybdate complex under conditions of low acidity (194). The concentration of a pure solution of sorbitol may be determined by means of the refractometer (195). Mass spectra of trimethylsilyl ethers of sugar alcohols provide unambiguous identification of tetritols, pentitols, and hexitols and permit determination of molecular weight (196). 

Tomiya, N., Suzuki, T., Awaya, J., Mizuno, K., Matsubara, A., Nakano, K., and Kurono, M., Determination of monosaccharides and sugar alcohols in tissues from diabetic rats by high-performance liquid chromatography with pulsed amperometric detection, Anal. Biochem., 206, 98, 1992. 

KATONA, Z.F., SASS, P., MOLNAR-PERL, I., Simultaneous determination of sugars, sugar alcohols, acids, and amino acids in apricots by gas chromatography-mass spectrometry, J. Chromatogr., 1999, 847, 91-102. 

ADAMS, M.A., CHEN, Z., LANDMAN, P., COLMER, T., Simultaneous determination by capillary gas chromatography of organic acids, sugars, and sugar alcohols in plant tissue extracts as their trimethylsilyl derivatives, Anal. Biochem., 1999, 266, 77-84. 

Determination of neohesperidine DHC by HPLC Determination of sugar alcohols... 

In theory the fermentation could be followed equally satisfactorily by measuring the alcohol content of the solution. In fact, however, alcohol determinations are much slower and more complicated than density determinations, so they are seldom, if ever, used. It is possible for the fermentation to stop—successive density determinations showing the same value—while there is some sugar left in the solution, although this is not normal behavior for fermentations. It is good practice to analyze for low levels of sugars in all wines when they have apparently completed their fermentations. 

After benzoylation, it was possible to analyze together the food substances of varying chemical structures, such as alcohols, esters of 4-hydroxybenzoic acid, phenolic antioxidants, saccharides, and sugar alcohols. The method allowed the determination of these substances in different matrices by the same analytical procedure, using the same cleanup. The preservatives were separated on an RP-18 column. Acetonitrile-water (50 35) or acetonitrile-water-butylmethyl ether (110 35 40) were used as mobile phases. Detection was UV at 230 nm (71). 

Quality control and analysis in the agro-food industry by the low resolution NMR was reviewed by D. N. Rutledge [83], in which NMR method is described as faster, more precise, simpler and cheaper technique than those traditionally used. For on-line monitoring of wine fermentation, EtOH and sugar alcohol beverage and fermenting musts were determined to a precision of 0.005-0.1% for EtOH and 4 8g/L for sugar by low resolution NMR [84]. 

While structural information on complexes of molybdenum(VI) and tungsten(VI) with sugar alcohols is available for solid-state as well as for solution species, crystal stmctures have not been determined so far for the corresponding complexes with aldonic and aldaric acids (compare O Sect. 3.2), that is, the following stmctural description is based solely on NMR spectroscopic data. 

Remark All substances with vicinal diol groups (sugars, sugar alcohols, glycosides etc.) yield a yellow-green fluorescence with this reagent. In order to determine which zones are produced by sugars the plate can be sprayed later with... 

These difficulties may be overcome by the method of Johnson and Sieburth (1977), who combined several well-known reactions of carbohydrates to gain specificity in the determination. Their spectrophotometric assay included reduction of free monosaccharides to sugar alcohols with KBH4, periodate oxidation and subsequent determination of the liberated formaldehyde with 3-methyl-2-benzothia olinone hydrazone hydrochloride. Since only one compound is actually determined (formaldehyde), the problems associated with varying responses of different sugars are eliminated. 

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