How does the Soybean Mosaic Virus effect food quality?
The soybean mosaic virus is transmitted in infected seed and is spread by aphids as they feed. The major symptom is a dark discoloration of the seed coat, which can range from dark brown to a deep black in color. One of the characteristics is the “bleeding hilum” or tear-stain effect from the virus. This is a localized discoloration which spreads from the hilum outward onto the seed coat. The name “tear-stain” comes from the appearance of the staining as if someone had dropped a tear onto the hilum which then spread outward onto the seedcoat. The reason that food processors will not accept SMV-infected soybeans is that the blackening of the seed coat can result in small black specks appearing in tofu or other such products once processing is completed. These specks are not harmful, but may give consumers the idea that the processing was not done properly or that some type of contaminant is present in the products. Most food-grade beans have light hilums for this reason when compared to
