Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: December 12, 2002
Publication Date: August 1, 2003
Citation: Eggleston, G., Grisham, M.P. 2003. Oligosaccharides in cane and their formation on cane deterioration. In: Eggleston, G., Cote, G.L., editors. Conformational Studies of Oligosaccharides. ACS Symposium Series 849. Washington, DC: ACS Publications. p. 211-232. Interpretive Summary: The deterioration of sugarcane in the field or at the factory is a major concern to the sugarcane industry. Sugarcane deterioration not only causes large economic losses for the growers and processors, but can seriously affect the running of the factory, and reduce the quality of the final, processed product, raw sugar. Oligosaccharides (short-chain sugars) are a direct and sensitive measurement of cane deterioration and can affect processing. For the first time, where most oligosaccharides occur in the cane plant is reported. In the U.S., especially Louisiana, sugarcane is now being mostly harvested into shorter pieces than long stalks. By monitoring oligosaccharide formation it was shown that deterioration occurs earlier and faster in the shorter cane pieces than the long stalks and that burning the cane in the field accelerates deterioration. However, if the time between harvesting and processing the short length cane is kept to within 14 hours, there will be no worse affect on factory processing. This work will impact scientists, giving them a way to better confirm cane deterioration, and also sugarcane growers and processors by letting them know how to better harvest, handle and store cane, in order to reduce deterioration.
Technical Abstract: Cane deterioration in the field, factory storage pile, or during factory milling processes has become a major technical concern in recent years, especially in those areas where mechanical harvesting of billeted sugar cane has increased. Not all deterioration products advocated as cane deterioration indicators impact future factory processing, but certain oligosaccharides directly impact processing by interfering with sucrose crystallization. Oligosaccharides are present in the cane before deterioration, with the tops (leaves and growing point regions) of the cane containing markedly more maltose, 1-, 6-, and neo-kestoses than the stalks. Chemical, enzymatic, and microbial reactions are all involved in cane deterioration and can cause the formation of oligosaccharides. The major oligosaccharides formed on deterioration are: 1-, 6-, and neo-kestoses (GF2), nystose (GF3), and kestopentaose (GF4) isomers, as well as those formed as acceptor products from the action of dextransucrase in Leuconostoc bacterial strains, mainly isomaltotriose, isomaltotetraose, leucrose, and palatinose. Mannitol is also formed on cane deterioration by mannitol dehydrogenase also from Leuconostoc bacteria, and its rate of formation is higher than for oligosaccharides or ethanol and it is known to increase the viscosity of cane process streams. This paper reviews the effect of cane harvest method and storage time on oligosaccharide formation, as well as the use of HPAEC-PAD to simultaneously detect oligosaccharides and oligosaccharide isomers, mannitol, and ethanol - all cane deterioration products.