Stephania Imbachi-Ordonez, Gillian Eggleston, Alexa Triplett and Lenn Goude
Audubon Sugar Institute, LSU Agricultural Center, St. Gabriel, Louisiana, USA; simbachiordonez@agcenter.lsu.edu
Crystal elongation is unwanted since it reduces crystallization rates and leads to higher molasses production with higher purities, centrifugation problems, and higher sucrose losses. Sucrose crystal elongation usually occurs because growth in certain directions is inhibited by an impurity rather than accelerated. Elongation can be caused by some polysaccharides, e.g., dextran, and shorter-chain oligosaccharides, e.g., kestoses. Since sugarcane processing seasons in Louisiana (LA) have been lengthened in recent years because of increased sugarcane tonnage, sugarcane has been crushed both earlier and later in the season. In the early 2022 season, many of the LA cane factories had unusual crystal elongation, even though Haze dextran was not high in concentration and dextranase did not alleviate the problem. The weather was dry and relatively warm. The severe crystal elongation (up to 7.9-fold elongation) was associated with microbial deterioration, indicated by lower fructose/glucose ratios and much higher-than-normal fructan in molasses, plus low juice pH. Dextran was confirmed not to be responsible for the elongation. Fructan (short and/or long chains of fructose) concentrations were higher inside the elongated crystals compared to normal crystals. A few oligosaccharides (trisaccharides) were found in elongated crystals that were strongly related to the elongation and fructan values of the crystal, and one was tentatively identified as levan triose. Further research is ongoing to identify and confirm if they cause elongation, and if other molecules also contribute.