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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #342144

Title: Quality attributes of sweet sorghum for the large-scale production of bioproducts: A 1 year comparison of commercial hybrids and a cultivar

Author
item Eggleston, Gillian
item Wartelle, Lynda
item Zatlokovicz Iii, John
item Petrie, Eric
item Cole, Marsha
item St Cyr, Eldwin

Submitted to: Sugar Tech
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2017
Publication Date: 6/1/2018
Citation: Eggleston, G., Wartelle, L., Zatlokovicz III, J., Petrie, E., Cole, M., St Cyr, E. 2018. Quality attributes of sweet sorghum for the large-scale production of bioproducts: A 1-year comparison of commercial hybrids and a cultivar. Sugar Tech. 20(3):347-356.

Interpretive Summary: Quality and processing attributes of sweet sorghum are critical to the development of a largescale industry for the manufacture of biofuels and bioproducts. Two commercial sweet sorghum hybrids 105 and 106, later and earlier maturing, respectively, were compared to a popular Top 76-6 cultivar, for agronomic, quality, and processing attributes at two maturity stages. Overall, the hybrids processed similarly to the cultivar and had the additional advantages of having low starch and no side stalks.

Technical Abstract: Quality attributes of sweet sorghum affect the industrial processing of this biomass into biofuels and bioproducts. In a one year study, two commercial sweet sorghum hybrids 105 and 106, late and early maturing, respectively, were compared to inbred, later-maturing Top 76-6 cultivar, for quality attributes at the soft dough (SD) and hard dough (HD) maturity stages. Crops were grown in South Louisiana, and juice was extracted from topped whole-stalks by roller milling. Crop biomass yields varied (P<0.05) with 105 > Top 76-6 > 106, with hybrid 106 containing markedly more auxiliary seed-head/stalk (side-branch tillers) compared to none in hybrid 105 and only 0.5% in Top 76-6 at HD. For the three genotypes, the stalk contributed between 63.8 to 86.5% of the fresh weight biomass which decreased from SD to HD. The growth parameters of crop yield, and stalk biomass, height, wet weight, first internode diameter, and to a lesser degree hardness of the last internode were strongly, negatively correlated with both soluble and insoluble starch in the raw juice. This suggested that increased growth/maturity of the genotypes tended to reduce starch. Overall, except for significantly (P<0.05) lower mode values in the hybrids compared to Top 76-6, there were little statistical differences in starch granule size parameters. Further studies are now warranted to ascertain environmental effects on quality.