Progress 09/14/09 to 09/13/11
Outputs
Progress Report Objectives (from AD-416) Develop a consistent �standard reference samples� to be used for comparison during training and evaluation of musty odors in grain sorghum. Approach (from AD-416) ARS and Kansas State University (KSU) are involved in the research of measuring grain quality characteristics. The parties agree that meeting the objectives of this project will serve to strengthen and enhance the research programs of both entities by furthering the understanding of improved tools and techniques to determine unacceptable odors in grain sorghum and potentially other grains. KSU will conduct research on the impact of �off� odor in sorghum on the chemical, physical and sensory quality of sorghum grain. ARS will provide samples with different degrees of off odors. KSU will study physical and chemical variations between molded and healthy sorghum grain. The project will be conducted as collaboration between ARS and KSU. 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 KSU on this project to determine a means to evaluate for �off odor� and the inherent chemical components that comprise the �off odor(s)�. ARS may share data with GIPSA. The overall collaboration should lead to the development of a sensory panel that may be used in assessing sorghum grain quality using sensory and chemical analyses. Some volatile compounds present in musty sorghum can be linked to musty odor notes, and even differentiated into two groups: �dry� and �wet� musty odor. Musty sorghum with �wet� odor notes seemed to have other off- odor notes stated as earthy/damp or moldy. The presence of these odor notes seemed to indicate a higher grade of deterioration in the grain when compared with the �dry� musty grain samples. The presence of some aromatic compounds (such as pyrazines and methoxybenzenes), in these samples was absent in the �musty, dry� sorghum grain samples. These differences between �dry� musty and �wet� musty sorghum grain, were corroborated by the sensory analysis results. A major finding, however, is that �musty� is musty regardless of whether it is subdivided into wet or dry musty. Both result in a clear sensory description call �musty�. 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.
Impacts
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) Develop a consistent �standard reference samples� to be used for comparison during training and evaluation of musty odors in grain sorghum. Approach (from AD-416) ARS and Kansas State University (KSU) are involved in the research of measuring grain quality characteristics. The parties agree that meeting the objectives of this project will serve to strengthen and enhance the research programs of both entities by furthering the understanding of improved tools and techniques to determine unacceptable odors in grain sorghum and potentially other grains. KSU will conduct research on the impact of �off� odor in sorghum on the chemical, physical and sensory quality of sorghum grain. ARS will provide samples with different degrees of off odors. KSU will study physical and chemical variations between molded and healthy sorghum grain. The project will be conducted as collaboration between ARS and KSU. 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 KSU on this project to determine a means to evaluate for �off odor� and the inherent chemical components that comprise the �off odor(s)�. ARS may share data with GIPSA. The overall collaboration should lead to the development of a sensory panel that may be used in assessing sorghum grain quality using sensory and chemical analyses. Some volatile compounds present in musty sorghum can be associated with musty odor notes, and can be differentiated in two groups: "dry" and "wet" mustiness, that combine to give an overall musty that is evaluated by grain inspectors. Musty sorghum with "wet" odor notes seemed to have other off-odorant notes as earthy/damp or moldy. The presence of these odor notes may indicate a higher grade of deterioration in the grain, compared with the "dry" musty grain samples. The presence in these samples of some aromatic compounds (such as pyrazines and methoxybenzenes) , which were absent in the "musty, dry" sorghum grain samples, corroborated the sensory analysis results. Some references/standards were elaborated using the instrumental aromatic data and the sensory descriptive analysis as the principle potential reference materials for mustiness in grain. These references can allow the USDA inspectors to unify and increase the consistency of the sensory analysis used to grade the sorghum grain. During the next months of the project, new chemicals will be considered (e.g. pyrazines) and used as references. Shelf life study will be continued, and recommendations about references preparation and use can be made. An aspect that needs to be considered for future work is that clean grain samples should be stored in various ways to determine how those storage conditions affect the appearance or disappearance of chemical aromatic compounds over time, and to study the relationship of these compounds with the degradation of the "clean grain odor". Such study would allow recommendations to be made for grain storage. ADODR monitoring is via on-site meetings/discussions, phone calls, emails.
Impacts
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