If a reward is processed food, can the project proceed by changing only the packaging?

Yes, you can proceed as a pre-order or funding project.

If only packaging is changed, it is difficult to recognize it as a new product, so you can proceed with a pre-order by structuring additional benefits. 

On the other hand, if you have changed the food item report number, you can be recognized as a new product and proceed with funding. Accordingly, you must submit your newly issued food item manufacturing report or change report.