The application of cassava and sweet potatoes flour for bakery product is presented in Figure 3. Each flour show give the bakery product that cannot swell well. Swelling power and solubility properties may influence the characteristics of bakery product. Flour which have lower swelling power and solubility cause the bakery product will not swell well. Tropical tubers flour do not have gluten, moreover it cannot provide a stabilizing network for retention of gas during baking. To meet the demanding technological needs of today, the properties of starch are modified by physical or chemical methods. Starch modification is conducted to evaluate one or some of the short comings, which will enhance its versatility and satisfy consumer demand.