Science Buddies: "Ask an Expert"

Recently I've learned how to extract DNA from vegetables.
When me and my class were in the lab, we were devided into teams.
My team used red sweet pepper/ bell pepper.
Every team that used the peppers, got bad results- the DNA came out as red dots instead of white strings.
However, the teams that used onions or cucumbers got perfect white strings.
I wanted to ask- did it happen for a reason? or was there just a problem with the peppers?

This is not normal, the pepper may have been the problem, its DNA may have changed due to exposure to chemicals or various infections!!!!