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Starch changes in cassava flours made from parenchyma (peeled root) cooked either in steam or in boiling water and stored at 57C or 2207C for 24 h were studied using differential scanning calorimetry (DSC), wide-angle X-ray diffraction and iodine binding capacity. The storage temperature of cooked parenchyma did not have a significant effect on starch retrogradation. For storage at 57C, flour from steam-cooked parenchyma presented a slightly higher melting enthalpy of retrograded starch and crystallinity compared to that of parenchyma cooked in boiling water. When stored at 2207C, the cooking procedure had no significant effect on the melting enthalpy of retrograded starch, crystallinity and blue value index (BVI). The water content in cooked parenchyma stored at 57C influenced the extent of retrogradation. The cooking method and the storage temperature are important parameters that might influence the physicochemical and functional properties of cassava flours.

-Deformability modulus, hardness, cohesiveness and adhesiveness of cassava dough reconstituted from precooked flour were evaluated using a lubricated compression test and texture profile analysis. Cassava parenchyma processed under different cooking conditions and left at either -5ºC or -20ºC for 24 h was used to make flour, which was reconstituted into dough. As temperature decreased to -20ºC during the storage period of cooked parenchyma, deformability modulus, hardness and cohesiveness of dough increased significantly. The temperature during the storage period was the most important factor affecting the textural properties of cassava dough.

The characteristics of the texture of cassava dough were evaluated using the stress–relaxation test and texture profile analysis. Cassava parenchyma processed under different cooking times, 15 or 18 min, and stored at either −5 or −20C for 24 h was used to produce the dough. Two stress–relaxation models, Maxwell and Peleg, were fitted to the experimental data. Both models were validated for quantifying the relaxation behavior; but the Maxwell model best fitted the experimental data. Dough samples from the parenchyma cooked for 18 min and stored at −20C showed the lowest elastic moduli, viscosities, initial compressive relaxation modulus and hardness values. It was concluded that higher cooking times and lower temperatures during the storage period increased the degree of retrogradation of starch granules, affecting the textural properties of cassava dough. PRACTICAL APPLICATIONS There are new and growing industries in cassava‐producing countries that use fresh cassava roots in order to produce high added‐value products like croquettes, fried chips or snacks. Cassava dough is an intermediate product for making cassava croquettes, which is a stick‐fried food well positioned in the Colombian market. The study of the rheologic and textural behavior of cassava dough is important for processing improvements in the cassava croquette industry. The results of this investigation showed that stress–relaxation test and texture profile analysis were sensitive to identify changes related to different processing conditions; in addition, the higher cooking times and lower temperatures during the storage period decreased the stiffness of cassava dough, affecting its handling in a following process.

The influence of water (60-70%) and salt (1-2%) content on the viscoelastic properties of cassava dough, reconstituted from cooked flour, was studied using a controlled strain rheometer. Reconstituted cassava dough behaved as a solid-like material with the storage modulus (G¢) predominant over the loss modulus (G 00 ). As the water content was increased, G¢ decreased and G 00 increased; but tan d was practically independent of the water content. This behaviour suggested that water had plasticising effects, but probably did not change dough structure. The effect of salt content on the dynamic rheological properties of cassava dough was not significant, except for G 00 values at water contents close to 60%.