Are gums produced in the factory? Quantification of gums isolated from mixed juice and final molasses

作者：Foxon K. M.^*; Du Clou H.

来源：International Sugar Journal, 2018, 120(1432): 288-295.

• gums
• dextran
• factory hygiene
• mixed juice
• final molasses
• microbial activity

Gummy massecuites in sugar factories are associated with exhaustion problems in pans and inefficient purging in centrifuges. Gums originate in stale cane because of microbial activity during burn/harvest-to-crush delays, especially in the rainy season, but are also thought to be generated by microbial activity within the factory. The proportion of gums generated within the factory is not known. This study investigated the phenomenon of gum formation in the factory by comparing the total amount of gums in mixed juice and in final molasses and considering the fate of gums in a factory. Gums were precipitated with acidified alcohol from weekly composite mixed juice and final molasses samples for a single factory over a period of 35 weeks in 2014. The total gum flows passing the mixed juice and final molasses scales were estimated from gum concentration and weekly flow data. The total amount of gums in the final molasses over the entire 35-week test period was 1 567 tonnes, and was less than the total amount of gums in mixed juice, at 1 655 tonnes. This indicates that overall, gums are not produced in significant quantities between the two sampling points for most of the crushing season. The result also shows that some of the gums measured in mixed juice leave in other factory streams, viz. raw sugar and filter cake for the factory in question. Data from the South African Sugar Terminal were used to estimate that dextran and starch in raw sugar from this factory may have accounted for approximately 40 tonnes of polysaccharides leaving the factory. An increase in gum flow in final molasses above that in mixed juice was only observed in the last few weeks of the season, indicating that some gum production had occurred in the factory during this period. Conditions conducive to gum production may be expected to occur during periods of unsteady operation such as interrupted cane supply. Measures to target and prevent gum production can therefore be justified when factors outside of the factory's control may lead to gum production in the factory.

• 出版日期2018-4