2011 Annual Report
GIPSA request ARS to conduct research on the impact of “off” odor in sorghum on the chemical, physical and sensory quality of sorghum grain. GIPSA agrees to award ARS resources to conduct the above research and provide samples with different degrees of off odors. ARS agrees to study physical and chemical variations between molded and healthy sorghum grain. ARS will provide a sub-award to Kansas State University to complete supplemental work to obtain chemical and sensory traits.
The project will be conducted as collaboration between GIPSA-ARS. A major criterion for evaluating sorghum grain quality is odor. Both domestic and international customers are very adept in their ability to detect “off odor” in sorghum grain. If an “off odor” exists a red flag immediately is raised and the quality of the sorghum is suspect. ARS would benefit by collaborating with GIPSA on this project to determine a means to evaluate for “off odor” and the inherent chemical components that comprise the “off odor(s)”. The collaboration may lead to the development of a sensory panel for GIPSA that may be used in assessing sorghum grain quality using sensory and chemical analyses.
Some references/standards were elaborated using the instrumental aromatic data and the sensory descriptive analysis as principal tools. These references will allow the USDA inspectors to unify and increase consistency in the sensory analysis used to grade sorghum grain. With these references, new criteria can be used for grading grain, if the secondary odor notes (“dry” or “wet” musty odor) are considered. Following the panelist recommendations, clean grain was used as the basis to prepare the references. Geosmin (0.1 ug/kg) and 1,2-dimethoxybenzene (100 ug/kg), and 3-octanone (100 ug/kg) and 1,2,4-trimethoxybenzene (100 ug/kg), were the chemical compounds chosen to reproduce the musty-wet and musty-dry odor notes respectively.
Progress of project was monitored via email.