Dynamic Rheological, Thermal, and Structural Properties of Starch from Modified Cassava Flour (MOCAF) with Two Cultivars of Cassava

The objectives of this study were to investigate alteration in the starch properties of modified cassava flour from two different local cassava cultivars from Indonesia at different fermentation times, provide structural information for starch molecules, and characterize the dynamic rheological and thermal properties. Resistant starch, non-resistant starch, and total starch levels in the cassava cultivars were also evaluated. Changes in the starch properties of Cimanggu and Kaspro (local cultivars of cassavas from Indonesia) were compared following different fermentation times (0, 12, and 24 hours). The properties of starch from modified cassava flour were influenced by the fermentation time, although both cassava varieties showed the same general characteristics. Their levels of resistant starch, non-resistant starch, and total starch were 33.28% to 51.74%, 20.51% to 23.72%, and 53.81% to 72.25% (g/100 g dry sample), respectively. The starch granules for the non-fermented samples were oval, polygonal, and round shapes; however, during fermentation, the starch granules became more porous and developed cracks of various sizes. The starches of both varieties showed an onset temperature between 67.85 and 70.17 °C, a peak temperature of 69.33 °C to 71.62 °C, and an end set temperature of 68.62 °C to 70.95 °C, with enthalpy values ranging from 1.25 mJ/mg to 1.74 mJ/mg.