Functional and physicochemical properties of flours and starches from different tuber crops.

Flours and isolated starches from different potato and sweet potato varieties were evaluated for their physical, functional, pasting, and thermal properties. The flours had higher protein and amylose contents than starches. The L values of the starches ranged from 91.92 (S-2) to 96.42 (S-1); thus, the whiteness of the starch samples was satisfactory. X-ray diffraction mode showed that potato starch could be a special material for crystalline nanomaterials with potential industrial applications. The starches had higher viscosity than flours. Therefore, starches can be used as thickeners in different food products. The flours exhibited high gelatinization temperatures but low enthalpy, which can be attributed to the effects of non-starch components in the flours, such as proteins and lipids. Potato flours and starches exhibited higher amylose contents and pasting characteristics and wider applications in the food industry than sweet potato flours and starches. The purple-fleshed varieties had high antioxidant activity. Therefore, the colorful flours of potatoes and sweet potatoes can be combined with other cereals for the development of functional flours with nutritional applications.