2.2.3. Cold-water viscosity of starch gels
The prepared starch pastes (Section 2.2) were poured into aluminum plates and transferred to an upright freezer set at −18 °C and kept overnight. The frozen gels were then freeze-dried in a freeze dryer (Dena Vacuum, Tehran, Iran). The pressure during freeze drying was maintained at 7 × 10−2 mbar or below. Afterward, the dried samples were milled and sieved through a 120-mesh screen sieve to obtain powders of similar particle size. The native corn starch was also used without being subjected to pasting after being sieved using a sieve with the mesh size 120. The cold water viscosity of the powders of corn starch gels and the native corn starch was then determined using a Rapid Visco Analyzer (RVA) (Starch Master2, Perten, Australia). An aliquot amount (3.00 g, dry basis) of the resultant powders was added to 25.00 g distilled water and mixed in a RVA canister in order to prevent lumps. Samples were then run in the RVA where they were mixed at 160 rpm (using the RVA paddle) and viscosity was recorded for 15 min at 25 °C. Viscosity-mixing time graphs indicating cold water viscosity were captured and then analyzed.