Effect of date syrup on pasting, rheological, and retrogradation properties of corn starch gels

The effect of date syrup on pasting, rheological, and retrogradation properties of cornstarch gels was investigated using an HR-2 Discovery Rheometer equipped with a pasting cell and parallel plate geometry. Pasting and rheological measurements were made on 6% (dry basis) corn starch with different levels of date syrup (starch:syrup; 1:0, 1:1, 1:2, or 1:3). The pasting measurements showed that addition of the date syrup increased the pasting temperature with increasing date syrup levels versus controls. Rheological measurements showed that peak viscosity and elastic modulus (G') increased with increases in date syrup (1:2-1:3) but this decreased at 1:1 versus control. Changes in elastic modulus as a result of cold storage for 1-wk decreases with increases in date syrup concentration. This suggested that the date syrup could be an effective sweetener in reducing starch gel retrogradation during cold storage.