I think tpu does come in food safe formulations. For a gasket that isn’t coming into contact with food, and wouldn’t regularly be washed anyway, I wouldn’t really have concerns. Especially if you can design the gasket thin enough to reduce the number of layer lines.

I’d have more concerns if the printed part came into direct contact with the food. Anything you’d want to put into a dishwasher is completely out of the question; thermoplastics don’t handle the high temps gracefully