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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #236022
Title: Clarification Properties of Trash and Stalk Tissues from Sugarcane

Author
item Eggleston, Gillian
item Grisham, Michael
item Antoine, April

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2009
Publication Date: 1/1/2010
Citation: Eggleston, G., Grisham, M.P., Antoine, A.C. 2010. Clarification Properties of Trash and Stalk Tissues from Sugarcane. Journal of Agricultural and Food Chemistry. 58:366-373.

Interpretive Summary: The effect of the world-wide change from burnt to unburnt (green) sugarcane harvesting on processing has not been fully characterized. Therefore, few solutions to minimize the detrimental processing effects of trash (leaves and tops) have been developed or implemented. Whole-stalks from five commercial Louisiana sugarcane varieties were harvested. Four sample tissues were collected: brown, dry leaves (BL), green leaves (GL), growing point region (GPR), and stalk (S) and juice extracted and clarified. Only GPR and GL juices followed the normal settling behavior of factory sugarcane juice, although GL was markedly slower than GPR. GPR juice aided settling. The quality not the quantity of impurities in the different tissues affected the volume of mud produced. GL and BL increased color, turbidity, and suspended particles in clarified juices with BL worse than GL.

Technical Abstract: The effect of the U.S. and world-wide change from burnt to unburnt (green) sugarcane harvesting on processing, and the use of sugarcane leaves and tops as a biomass source has not been fully characterized. Sugarcane whole-stalks were harvested from the first ratoon crop of five commercial, Louisiana sugarcane varieties (LCP 85-384, HoCP 96-540, L 97-128, L 99-226, and L 99-233). Replicated sample tissues of brown, dry leaves (BL), green leaves (GL), growing point region (GPR), and stalk (S) were separated. Composite juice from each tissue type was clarified following a hot lime clarification process operated by most U.S. factories. Only GPR and GL juices foamed on heating and followed the normal settling behavior of factory sugarcane juice, although GL was markedly slower than GPR. GPR juice aided settling. S juice tended to “thin out” rather than follow normal settling and exhibited the most unwanted upward motion of flocs. Most varietal variation in settling, mud, and clarified juice (CJ) characteristics occurred for GL. The quality not the quantity of impurities in the different tissues affected the volume of mud produced: After 30 min settling, mud volume per unit tissue juice oBrix (% dissolved solids) varied markedly among the tissues (S 1.09, BL 11.3, GPR 3.0, and GL 3.1 ml/oBrix). Heat transfer properties of tissue juices and CJ’s are described. Clarification was unable to remove all BL cellulosic particles. GL and BL increased color, turbidity, and suspended particles in CJs with BL worse than GL. This will make the future attainment of Very High Pol (VHP) raw sugar in the U.S. more difficult. Although optimization of factory unit processes will alleviate extra trash problems, economical strategies to reduce the amount of green and brown leaves processed need to be identified and implemented.