What types of food can you think of that might lead to pleasure? Let me begin with the one that is probably the last on your list a possible toy.
Ice cubes or ice cream with some whipped cream are perfect for a foreplay. A cube can be left in the belly button, for instance, and your partner is not allowed to move while it melts, or you are not allowed to touch him or her during that time, as part of a game. Or, you can lick ice-cream off of his or her body, adding the contrast of the cold cream and your warm tongue to the foreplay.
As for penetration itself, there are quite a lot of fruits and vegetables that can be inserted. A year ago, I would have also listed salami here, as well, a young girl passed away due to an infection she got while masturbating with salami. Needless to say, that proper cleaning and/or a condom on the food is highly suggested in any case to avoid infection. Besides, if you use a peeled banana, a condom is the only way to make sure that it would not break into the vagina or asshole.
So, what else can be used for penetration besides banana? Cucumber and zucchini are also perfect choices, even though you need to be careful with zucchini, as it can be prickly at the base.
Be creative and use everything you can, to spice up your sex life with various foods!