Fungal infected sorghum grains are not suitable to use in food products and have reduced germination rates. While there are commercial sorting systems that can remove sorghum grains having severe discolorations due to fungal damage, many fungal damaged grains cannot be removed by these systems as the fungi may only cause minor discolorations in the form of several tiny spots on the surface of the grain. To address this issue an improved electronic-optical sorting system was developed to identify and remove sorghum kernels that have both large discolorations and several tiny spots. The system uses a color image sensor and digital processor programmed to detect most types of fungal damaged sorghum. Results indicate that nearly 100% of the grains with large discolorations and 90% of the grains with tiny spots can be separated from clean sorghum with only a 10% error rate on the clean sorghum. The throughput of the system is approximately 30 kg/hr. The sorting system can be used to improve the sorghum quality of food products and seed germination rates and might also be used for other grains or pulse crops for which seeds with localized spots need to be removed.
Contact Tom Pearson, telephone 785-776-2729, email Thomas.Pearson@ars.usda.gov
Article was originally published in The Center for Grain and Animal Health Research (CGAHR)'s Research Kernels November Edition Part Two.