

Spots on cannellini beans
I made lunch last night. I washed some leaves with water and added cannellini beans from a can, tuna from a can and some chopped walnuts. I put some salt and pepper last night and then added olive oil and distilled vinegar this morning.
When I opened the container at lunch time I noticed all those dark spots on the beans. Any ideas why they look like this? They looked fine when I rinsed them yesterday