I thought that powder coating was for metals only?? Maybe you mean a baked-on finish? I'm not too clear on this, but I do know that if you are touching up by using a different method from the original finish, it's going to show. You might have to prime them and paint them entirely.

Perhaps someone else will be able to offer an opinion, or will have done this before themselves...

MDF can be powder coated , but it will be very difficult to paint after depending on the type of cure that was used , some use a UV cure that make it nearly impossible to paint on after

Integra Doors, Greer, SC makes custom powder coated cabinet doors. It is a very durable finish that doesn't yellow. If your doors really are powder coated, then the only way to paint them is by sanding them completely. I doubt that they are powder coated though. Integra Doors is the only custom door maker that is doing powder coating of mdf cabinet doors - and they opened in Sept 2015.

I would suggest trying to find the manufacturer of the cabinetry, then order a touch up kit. Look at the side of drawers, sometimes the maker is stamped on drawer box. Or maybe a sticker inside the sink base. Trying to match up a finish can be tricky if not done by the manufacturer.

guys, post is four years old. I'm sure your advice is timeless, but the rest of us like a chance to see the newer threads too...