Reducing sugars compound separation

Polarimetry The determination of sucrose and reducing sugars in fruit and fruit products by polarimetry is an AOAC recommended method. The polarimeter measures the rotation of plane polarized light caused by a solution containing an optically active compound. Separate measurements for the quantification of sucrose and reducing sugars can be made with the Clerget-Hertzfeld double-polarization method. 

The C-4 position of maltose can be modified in a similar way. Maltose, being a reducing sugar, usually has to have C-1 protected. C-1 is often protected by forming the 1,2-0-isopropylidene derivative. It has been obtained in a 33% yield and represented one of four isopropylidene compounds that were formed [111]. These compounds had to be separated on a silica-gel column. The 1,2-isopropylidene maltose is then reacted with 1,1-dimethoxy benzaldehyde to give the 4, 5 -benzili-dene derivative (reaction 4.116). The other free hydroxyl groups are protected by benzoylation, and the C-4 -0 bond is selectively cleaved to produce the free C-4 ... 

The above chemicals can be obtained by fermentation (qv) of other sugars. However, some compounds require sucrose as a unique feedstock. Examples are the polysaccharides dextran, alteman, andlevan, which are produced by specific strains of bacteria (48,54—56). Dextrans are used to make chromatographic separation media, and sulfated dextran derivatives are used as plasma extenders (41). Levans show promise as sweetness potentiators and, along with alteman, have potential as food thickeners and bulking agents in reduced-caloric foods (55,56) (see Carbohydrates). 

---