|GATEUIL, AUDREY - Agro Paris Tech|
|JACKSON, WINDELL - American Sugar Cane League|
|WAGUESPACK, JR., HERMAN - American Sugar Cane League|
|BLACKWELDER, NATHAN - American Sugar Cane League|
Submitted to: Sugar Bulletin
Publication Type: Research Notes
Publication Acceptance Date: 8/16/2010
Publication Date: 9/10/2010
Citation: Eggleston, G., Viator, R., Gateuil, A., Jackson, W., Waguespack, Jr., H., White, P., Blackwelder, N. 2010. Seasonal variations on sugarcane trash quantity and quality that directly concern factory processors and refiners. Sugar Bulletin. 88(12):22-27.
Technical Abstract: In sugar manufacture, there is a trend in the United States and worldwide to produce very high purity (VHP) and very low color (VLC) raw sugars for vertical integration from the field to the refinery. New refineries in Louisiana (LA) are expected to be operational in the next few years. One of these refineries requests lower ash concentrations in the VHP/VLC sugar for liquid sugar manufacture and short, medium, and long-term refinery strategies. Great variations in the color and quality of raw and VHP/VLC sugars exist mostly because of the range in quality of the cane supply (Muir and Eggleston, 2009, SIT paper #960). Strategies to control the quality of the cane supply will largely depend on the quantity, quality, and type of sugarcane trash (green and brown leaves plus top) processed at factories, which, in turn, will strongly be affected by seasonal variations. This study was undertaken to ascertain the variations in juice quality parameters that affect VHP/VLC manufacture and refining across the LA 3-month processing season (late Sept to Dec) in 2009. Across the season, air temperature decreased and there was consistent rainfall especially in Dec. Juice was extracted from separated stalk (S), growing point region (GPR or top), green leaf (GL) and brown leaf (BL) tissues of three popular sugarcane varieties (HoCP 96-540, L 99-226 and L 99-233), six times between Sept and Dec 2009. For all three varieties, total trash decreased across the season but GL levels were consistently higher in HoCP 96-540, and by Dec total trash was lowest in L 99-226. As expected, theoretical sugar recovery and juice purity values of stalks increased across the season. In the U.S., premiums for low color in sugar are paid on color measured at pH 8.5 whereas the rest of the world measures ICUMSA color at pH 7.0. In this study, color at pH 8.5 accentuated varietal differences in juice more than at pH 7.0 and was also more sensitive to GPR and GL colorants that are responsible for causing the color of raw, VHP/VLC and affinated sugars (Muir and Eggleston, 2009, SIT paper #960). There was a strong varietal difference for starch. Unlike in previous years with an older variety, starch processed at LA factories now increases up to the end of Nov and decreases in Dec. This suggests the need for breeding programs to include quality parameters as selection criteria. Fiber did not vary considerably across the season for all varieties. Ash was highest in all tissues at the beginning of the season (Oct 9), decreased in the middle of the season then increased again at the end of the season. Leaf moisture, juice extraction, and tissue pH variations are also discussed.