Medium quality ingredient - nutritionally adequate and unlikely to cause any problems
Potato starch in dog food
Potatoes are becoming more popular in dog foods as anti-grain sentiment continues to increase. Potato starch often forms the all important binding agent in grain-free dry foods, without which the biscuits simply wouldn't form.
Unfortunately, while whole potatoes contain a range of healthy nutrients, pure potato starch contains... well, pure starch and many nutritionists still have doubts over whether dogs can digest significant amounts of starches efficiently.