Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 21, 2005
Publication Date: January 31, 2006
Citation: Bean, S., Chung, O.K., Tuinstra, M.R., Pedersen, J.F., Erpelding, J.E. 2006. Evaluation of the single kernel characterization system (SKCS) measurements of sorghum grain attributes. Cereal Chem. 83:108-113. Interpretive Summary: Sorghum is the third leading cereal grain in the U.S. Traditionally, sorghum is used as animal feed in the U.S. However, worldwide approximately 40% of the world sorghum production is used as human food. An important quality factor in milling, processing, and food quality of sorghum is kernel hardness. Kernel hardness also plays a role in mold and weathering resistance. Traditionally, a wide number of techniques have been used to measure kernel hardness in sorghum. The single kernel characterization system (SKCS) is widely used to measure wheat hardness along with moisture, kernel weight, and diameter. This paper evaluates the use of the SKCS for measuring sorghum hardness, moisture, kernel weight, and diameter. The SKCS is a rapid technique requiring ~ 3 min per sample, and also provides information on the uniformity of grain samples. Thus, the SKCS has the potential to be a valuable tool in assessing sorghum grain and end-use quality.
Technical Abstract: The single kernel characterization system (SKCS) has been widely used in the wheat industry and SKCS parameters have been linked to end-use quality in wheat. The SKCS has promise as a tool for evaluating sorghum grain quality. However, the SKCS was designed to analyze wheat, which has a different kernel structure from sorghum. To gain a better understanding of the meaning of SKCS predictions for sorghum grains, individual sorghum grains were measured for length, width, diameter, and weight by lab methods and also by the SKCS. Kernel weight was highly correlated (r=0.98, slope=1) to weight as measured on an analytical balance. SKCS predictions for kernel diameter were highly correlated to kernel diameter as measured with digital calipers (r=0.94). However, the absolute values between the SKCS and caliper diameter measurements differed by ~20%. The SKCS moisture prediction for sorghum was evaluated by tempering seven samples with varying hardness values to four moisture levels. The moisture contents predicted by SKCS were compared to a standard oven method and while correlated, the SKCS moisture predictions were less than moisture measured by air oven, especially at low moisture content. Finally, SKCS hardness values were compared to hardness measured by abrasive decortication.