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United States Department of Agriculture

Agricultural Research Service

Research Project: Postharvest Quality and Processing of Sugarcane and Sweet Sorghum for Sugar and Ethanol Production

Location: Commodity Utilization Research

Title: Improved control of sucrose losses and clarified juice turbidity with lime saccharate in hot lime clarification of sugarcane juice and other comparisons with milk of lime

Authors
item Eggleston, Gillian
item Legendre, Duane -
item Pontif, Kevin -
item Gober, Jessica

Submitted to: Journal of Food Processing and Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 3, 2012
Publication Date: February 1, 2014
Citation: Eggleston, G., Legendre, D., Pontif, K., Gober, J. 2014. Improved control of sucrose losses and clarified juice turbidity with lime saccharate in hot lime clarification of sugarcane juice and other comparisons with milk of lime. Journal of Food Processing and Preservation. 38:311-325.

Interpretive Summary: A comparative factory investigation of adding lime as a suspension in water (milk of lime MOL) or as a solution in hot juice (lime saccharate SACCH) in hot lime clarification of juice at a U.S. sugarcane factory was undertaken. Performance was measured across the 2009 processing season after a preliminary factory study in 2008. SACCH caused lower turbidity in CJs with better control, as well as higher and better controlled CJ pHs which reduced expensive sucrose losses. Although SACCH produces slightly higher mud volumes than MOL, the advantages were greater than the disadvantages.

Technical Abstract: A comparative investigation of adding milk of lime (MOL) versus lime saccharate (SACCH) in hot lime clarification of juice at a U.S. sugarcane factory was undertaken to quantify performance across the 2009 processing season after a preliminary factory study in 2008. SACCH was prepared by adding hydrated lime to hot clarified juice (CJ) in a greater than 1:7 ratio. The lime treatment was added to flash heated juice (FHLJ) to obtain a target CJ pH of 7.3. Samples of FHLJ and CJ were collected six times every 30 min taking into account the retention time of the clarification tank. Results from the preliminary study suggested SACCH caused lower turbidity in CJs with better control, as well as higher and better controlled CJ pHs. Across the 2009 season, SACCH mud volumes tended to be slightly (no significant difference) higher than for MOL but no greater than 8.5%. In 2009, CJ turbidities with SACCH were, generally, lower and better controlled than MOL. Lower median particle sizes in CJs with MOL across the season at least partially explain the higher CJ turbidities with MOL than SACCH. For the same amount of hydrated lime added, SACCH produced a higher pH than MOL and this, generally, allowed SACCH to achieve the target CJ pH better than MOL and reduce sucrose losses from acid inversion. No significantly (P<0.05) extra lime had to be added in the SACCH than MOL treatment and there were no significant differences between the color of either FHLJ or CJ from SACCH or MOL. Overall, the use of SACCH over MOL improved hot lime clarification especially with respect to the achievement and control of target pH values that saved a considerable amount in sucrose losses and improved turbidity values of clarified juices.

Last Modified: 8/29/2014
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