Organic Brussel sprouts strange white substance, Help
Just bought lots of Organic Brussel sprouts from the store, got home was beginning to prepare them. Noticed a white substance, some spots had white tiny "chunks" which turn to nothing when you touch it and just powdery on other spots inside of the leaves. I have pulled off at least 6 leaves and it's like this beneath each one.... I was thinking powdery mildew but it's multiple leaves in.... not sure what this is or if it's safe to consume after cleaning them to the best of my ability. Please help
What I am seeing on the sprout looks like feeding injury from a true bug. Maybe harlequin bug or stink bug. The damage comes from the piercing mouth parts that are stabbed into the leaf followed by the feeding, which is the sucking out of the contents of the cells. This feeding obviously is going to kill the cells. If some extra juice was pushed out after the bug finished feeding and left, it may dry as a white powder. The little halo around the feeding wound is another indication that this is very likely bug feeding injury.
What I see in your pictures does not look like a fungal or bacterial pathogen. I don't know of any viruses that would cause that kind of problem either. From what I know of plants, I would say the feeding injury is the most likely problem and it shouldn't be toxic or contagious for you to eat the sprouts.
If you would like a more definite confirmation that this is feeding injury, you may want to take a sample in to your local office of NC Cooperative Extension. There is one in every county. If you aren't sure where yours is located type in the name of your county followed by .ces.ncsu for example johnston.ces.ncsu in the web browser address line and it should take you to the website for your county office.
I hope this has been of some help.