How to remove smell from plastic lid

After washing them, fill them with a mild bleach solution (one tablespoon for each cup of water) and let them out in the sun exposing the stain for a whole day. Make sure children and animals cannot reach the containers with bleach.

There used to be a product called Cascade Plastic Booster that you could add to your dishwasher that would remove the stains. It's no longer sold but its main ingredient was benzoyl peroxide at 5%, which you may buy in most drugstores.

I agree with Paul on this one. Glass, freezable containers are your best bet. I like to use the smaller glass bowls that Pyrex puts out. (just search for "freezer safe glass food storage") They are a good size for 1-2+ portions, and come with flexible air tight lids. Perfect for freezing or refrigerating. Just check the label to make sure you are picking out a glass container that can handle freezing. As an added bonus, glass containers are great to microwave in, as the glass is virtually inert, and does not impart any weird flavors(or chemicals) to the food.