I have a WHOLE can too, you don't have to switch to a brand new food ASAP, but you can feed it to your other fish. I do that with betta foods I don't like.
Wheat Flour is the 1st ingredient. But that's why it floats so well.
TetraBetta Plus = wheat flour #1
TetraBetta = wheat flour #1
TetraMin Tropical Granules = 3 types of pellets, fish meal is the 1st ingredient, rest are starches, soy, potato, rice, corn etc..
Some people have fed their bettas this food and they've lived 2-3 years.
Stick with the food you have for now.
Routine water change schedule is what you should develop first.