Comparison of cane and beet sugar macromolecules in processing

The major macromolecules in sugar processing include colorant and polysaccharides, along with minor amounts of protein, soluble lignin, colloidal silicates and possibly calcium complexes. These high molecular weight components negatively affect sugar processing and have been implicated in the inclusion of color in crystals, formation of color on storage, processing problems, and final product quality issues, such as turbidity and acid beverage floc. It has long been accepted that the high molecular weight components are the most difficult to remove during refining. However, it is also of interest to note that the transfer of color (from syrup to crystal) is much higher in cane sugar processing than in beet sugar processing. White beet sugar, with color of 20-30 IC, can be boiled from 2000-3000 IC color syrup, but only from about 200 IC with cane syrup. In chromatographically separated beet molasses extract, the color of the syrup can be as high as 5000-7000 IC and still produce a 30-50 IC sugar. What is the reason for this? This paper presents recent studies comparing beet sugar and cane sugar colorant and polysaccharide. The results indicate that beet and cane colorant are fundamentally different: Beet colorant tends to be produced during processing, mainly from alkaline degradation of invert and melanoidin formation, while cane colorant enters the process in the cane juice as plant pigments associated with polysaccharide, and changes very little in process, due to the milder conditions associated with cane processing.