Production of partially gelatinized cassava starch: Effects of preheating temperature and starch concentration on physicochemical characteristics during the spray-drying process

Abstract

Starch has application in several industrial sectors, such as food, textile, paper, pharmaceutical, among other industries. To meet this demand, native starches have been modified by chemical, physical and enzymatic methods. Cassava is the second source of starch. Furthermore, understanding the effects of spray-drying modification on the structural and physicochemical characteristics of its starch is important. Therefore, this study aimed to evaluate the effects of the main interfering factors in the process of spray-drying on the characteristics of cassava starch, aiming at increasing the industrial applicability of this starch. A Central Composite Rotational Design (CCRD) was employed to assess the experimental data. Experimental design included four factorial points, four axial points and three replicates of the central point. The starch concentration ranges from 5 to 11 % and preheating temperature ranges from 54 to 60 °C. Results showed influence of the variable factors on the characteristics of cassava starch. The processing conditions that allowed obtaining pregelatinized starches with higher viscosity at room temperature, higher resistance to hot and agitation, lower retrogradation tendency, and with partial solubility, desired quality parameters for this product were: 6 % of starch concentration (wet basis) and 60 °C of preheating temperature.