Colourants - Recovery

In Recovery the sugar contained in rejected affination syrup and refined syrup is crystallized and melted in the affination melter. During crystallization, colourants with high affinity to crystal will be incorporated in the recovered sugar and sent back to the beginning of the refining process. Recovery operation is not eficient, on colourants separation point of vue, as the more prejudicial colourants are not completely separated and sent to residual syrup, molasses.

In Recovery section syrups and massecuites present a brix between 80º and 92º. Colour formation, due to Maillard reaction, melanoidins may be formed in massecuites (in boiling and crystallizers) and in molasses storage due to their higher concentration and impurities present. These compounds will give a dark brown colour to these products and can provoke foam formation during boilings.This reaction of colour formation can happen at high velocity causing explosions. Any storage recipient of massecuites and molasses must be ventilated and with the security devices to minimize consequences of possible explosions.

Chromatogram and ELS diagram of molasses are presented in Figures 1 and 2 (Bento et al, 1997).
Sugar produced in Recovery section is returned to Affination. Colourants integrated in this sugar will influence affination liquor quality.

Figure 1 - Chromatrogram at 330 nm of Molasses

Figure 2 - ELS of Molasses

Bibliography
Bento L.S.M., (2008) Colourants throgh sugar production and refining,

SPRI Conference; Zuckerindustrie, March, April 2008

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