Functionality of Tuber Starches

Abstract Root and tuber crops form an important part of the diet in many tropical belts and are rich in starch; cassava and sweet potato being widely used for starch extraction. Unlike cereal starches, these starches show a wide range of property and are hence used in food and industry. Modified starches from these crops are becoming more important. Until recently, only cassava and sweet potato starches were studied in detail, but of late, the other tuber starches have been subjected to lot of investigations. In this chapter, extraction, properties, uses, and modifications have been described in detail. Among the physicochemical properties, granule size and shape and structural properties studied by XRD and molecular analysis, amylose content, and structure are very diverse among the starches. Wide variation in swelling characteristics and solubility patterns and thermal properties determined by differential scanning calorimetry indicates not only the effect of origin but also the environmental and processing conditions. Viscosity, pasting, and rheological features also exhibit a similar trend. Digestibility, another important attribute in food applications, has been investigated in detail. Various modifications—physical, chemical, and enzymatic—have been carried out on these starches to suit to different applications and discussed.