cooked in crockpot for 8+ hours on low with enough beef stock with salt, pepper, garlic powder and onion powder to cover them. Stirring twice. When I spooned them out some were black. They were purchased from Publix, they were clean & recleaned and they were in date. I tased the normal color ones and they were delicious. I fed some to my dog she loved them. This was my first time cooking them in a crockpot did I do something wrong? Can I eat them or should I toss them out? Thank you in advance.