Is blending food a physical or chemical change?

For the purposes of a basic chemistry course, blending food is a physical change since it typically involves only a change in particle size to create a mixture.

There are cases where blending food causes chemical changes, for instance when mixing the ingredients to make muffins. In this case, the baking soda and acid combine to produce carbon dioxide (among other things), and certain protein substances in the flour combine chemically to form gluten.

In the simplest case, however, the blending of food is a physical change.