I froze some leftover cabbage a few weeks ago to use up with mash as bubble and squeak, well I defrosted it today and some of it had gone purple, just like purple cabbage but I've never bought the purple kind only green. I didn't use it in case it was some kind of nasty bacteria.
Any ideas what happened? I've tried google but no luck. 
Retiring and living frugally in money from downsizing after years of stress
