Is a 1045 carbon steel katana ok for cutting fruit and if so what type of would you be able to cut?

A 1045 carbon steel katana is not the right tool for cutting fruit, or for any kitchen cutting task. It's a sword, and kitchen knives are specially designed for food prep. Swords also have a unique curve and geometry tailored to combat, which makes them ill-suited for precise cutting. Additionally, using swords in a kitchen can be hazardous, as they are not made for cutting food and could cause serious injuries.

If you're looking for a versatile and safer tool for cutting fruit, consider investing in a good quality chef's knife or utility knife. These knives are designed for kitchen use, are easier to handle, and come in a variety of shapes and sizes for various tasks.