HADPBy Bento, Luis San Miguel
Posted on 2007-07-23 Last edited on 2009-09-24
Invert sugars, present in sugar solutions, when in high alkalinity conditions, form compounds of strong colour, named HADP (Hexoses Alkaline Degradation Products). This formation may happen during Clarification, during extraction, and in Carbonatation, in the refining process (Bento, 1999), where sugar solutions are mixed with calcium hydroxide.
HADP spectrum at pH 9
ELS diagram of HADP
In the next figure it is presented the UIV variation of HADP (Bento, 2002). UIV is the Indicator Value in the UV spectrum.As it is observed, this curve presents a minimum at 262nm. The expression UIV means the IV in the UV radiation zone and represent the quotient between the solutions absorvancies at pH 9.0 and pH 3.0, between 220nm e 330nm.
UIV curve of HADP
In the next figure it is presented the HADP chromatogram obtained by sucrose chromatography (Bento, 1994). In this chromatogram it is observed that HADP are divided in two groups. The first one eluted with the less polar eluent (propanol-1) at 19min of Rt, and a second one with 62min of Rt, eluted with methanol. This result shows that HADP present a group of compounds with some degree of hydrophobicity, eluted with the less polar eluent, and another group of more polar compounds.
Sucrose Chromatogram of HADP
Bento L.S.M., 1994, Separation of sugar colourants using sucrose crystals in chromatographic columns,
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