In all honesty, the food thing is more germaphobia (properly mysophobia) than OCD. The two can go hand in hand, such as in the commonly known handwashing OCD, but they are not necessarily conjoined. Many germaphobes will obsess over it, and develop OCD symptoms, but a lot of OCD has nothing to do with cleanliness. Much OCD behaviour centers around turning things on and off, to make sure they're off.
A friend of mine would cook her breakfast, and found herself getting to work later and later because she'd have to go back home to make sure the stove was off. Three or four times. She just couldn't be sure. It was beginning to get bad, and the first thing she did was outwit herself - she had me disconnect the stove for her, and got those microwave breakfast sandwiches. Then she got a new stove she felt she could trust, and I rerouted the gas line so there was an accessable valve right beside the stove that she could shut off. After that workaround though, she started obsessing about the water faucets.
That's when she got some help. She's a lot better now. Still shuts off the gas for the stove when she's done cooking, though.
Can't be too careful!