|Gateuil, Audrey -|
|Fenger, Julie-Anne -|
|Jackson, Windell -|
|Waguespack, Jr, Herman -|
|Blackwelder, Nathan -|
Submitted to: International Sugar Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 12, 2013
Publication Date: July 1, 2013
Citation: Eggleston, G., Viator, R., Gateuil, A., Fenger, J-A., White, P., Jackson, W., Waguespack, Jr, H., Blackwelder, N. 2013. Effects of seasonal variations of sugarcane stalk and extraneous matter quantity and quality as they affect recoverable sugar, starch, and fiber: Part 1. International Sugar Journal. 115(1375):477-487. Interpretive Summary: There is presently a trend to manufacture high quality raw sugars for supply to refineries, as well as a trend to use sugarcane leaves and tops for biomass. Strategies to improve the quality of raw sugar will require attention to cane quality factors as well as process manipulations. This study was undertaken to ascertain seasonal cane supply variations in juice quality parameters that affect raw sugar manufacture across the Louisiana 3-month processing season. The maturity characteristic of the cane variety plays a critical role in seasonal variation of quality parameters, especially starch. Overall, for starch and fiber quality parameters studied the type of tissue had the strongest effect, followed by variety, then date of harvest; the varietal effect was greatest in the stalk than other tissues. This suggests that breeding programs could include quality parameters as selection criteria.
Technical Abstract: Raw sugar quality is dependent on the quality of the incoming cane supply across the processing season which, in turn, is greatly affected by the quantities and types of non-stalk tissues present. This study was undertaken to ascertain seasonal cane supply variations in juice quality parameters that affect raw sugar manufacture across the LA 3-month processing season (late September to December) in 2009 and 2010. Across both seasons, the maximum air temperature decreased with little difference in the season average values (~23.3 °C), but there was consistently higher rainfall in 2009 (13.7 mm) compared to 2010 (1.8 mm). Juice was extracted from separated stalk (S), growing point region (GPR or top), green leaf (GL) and brown leaf (BL) tissues of three commercial sugarcane varieties: HoCP 96-540, L 99-226 and L 99-233, at least five times between Sept and Dec. For all three varieties across harvest dates, the average total trash value (GPR + GL + BL) was 20.6%. The most popular LA variety HoCP 96-540, still had relatively high levels of total trash until late Nov, which can be mostly attributed to the GPR, GL, and BL levels remaining relatively high. There was a significant (P<.05) harvest date by varietal interaction for stalk theoretical recovery of sugar which increased across the season. The maturity characteristic of the variety played a critical role in seasonal variation of quality parameters, especially starch. Compared to early and mid-maturing varieties, L 99-226 and HoCP 96-540, respectively, which mostly delivered starch to the factories in green leaves, the later maturing variety L 99-233 delivered starch mostly in the stalk after mid Oct. Thus blowing off trash in the field or at the factory for L 99-233 would help little to control starch levels after mid October. The greatest (P<.05) variation in the effect of harvest date on starch concentration was in the stalk; there was also a very strong varietal effect on starch. In contrast, the least varietal variation in juice quality parameters occurred in the GPR. Fiber did not vary considerably across the season for all varieties. Overall, for all parameters studied the type of tissue had the strongest effect, followed by variety, then date of harvest; the varietal effect was greatest in the stalk than other tissues. This suggests that breeding programs could include quality parameters as selection criteria.