2.2.2. Stress relaxation behavior
Stress relaxation tests were performed using the texture analyzer. Cylindrical starch gel sections (20 mm diameter × 10 mm high) prepared according to the Section 2.2 were compressed to 25% of their original height using a 40 mm aluminum cylindrical probe at the speed of 2.00 mm/s. After compression the force values were then collected over a period of 120 s during which the probe position was kept unchanged. To determine the texture components the generalized Maxwell model with three elements was then used to analyze stress relaxation data. Most relaxation curves can be fitted by this model with two or three exponential terms (Peleg & Pollak, 1982). Maxwell model can be written as follows: