Food Atlas (20 sheets) Iron and other ingredients. Potatoes contain a lot of starch, protein and colloidal citric acid, lactic acid and potassium salt. Beef is sweet and flat, which can nourish the spleen and stomach, invigorate qi and blood, strengthen bones and muscles and quench thirst. There is a folk saying that "beef tonifies qi and astragalus works". The protein of beef is twice that of pork, but the content of fat and cholesterol is much lower. Potatoes with beef is a very scientific food.