Effects of Five Drying Methods on the Properties of Sour Cassava Starch

In order to explore the effects of different drying methods on the properties of sour cassava starch (SCS), which were processed from cassava starch by lactobacillus fermentation, and then dried under five drying methods including hot air drying (HA), heat pump drying (HP), vacuum freeze drying (VF), spray drying (SD) and sun-drying (S). The properties of SCS were determined, and the comprehensive score was evaluated by coefficient of variation method. The results showed that the SCS processed by HA, with the highest span value of 2.36, had the lowest clarity, blue number and oil retention of 21.57%, 8.96 and 1.74 g/g, respectively. The SCS dried by HP had the lowest specific area of 351.83 m2/kg, had the highest bulk density, water separation and retrogradation of 0.87 g/m, 33.02% and 74.89%, respectively. The product dried by VF, with the lowest bulk density, repose angle and water separation of 0.73 g/mL, 37.49° and 4.64%, respectively, with the highest clarity. Blue number and water-holding ability of 27.03%, 19.64 and 1.43 g/g, respectively, as well as the highest solubility. The SCS processed by SD had the highest specific area, repose angle and oil retention of 407.43 m2/kg, 54.11° and 2.33 g/g, respectively. However, it had the lowest retrogradation of 67.00%. The SCS dried by S, with the lowest span value and water-holding ability of 1.73 and 1.08 g/g. Comprehensive score results indicated that the SCS dried by VF, SD, S, HA and HP, with the comprehensive score of 0.60, 0.38, 0.18, −0.50 and −0.64, respectively. In summary, the best properties of SCS products could be obtained by VF, followed by SD, and then by S, HA and HP were the worst.