Modification of structural and physicochemical properties of repeated freeze-thawed cycle maize starch

To investigate the effects and mechanisms of repeated freeze-thaw cycles treatment on starch-based foods, structural and physicochemical properties of maize starch granules were investigated under repeated freeze-thaw treatment with 0, 3, 6, 12, 18 and 24 times at -20 degrees C, -40 degrees C and -80 degrees C, respectively. The x-ray crystalline pattern of the maize starch was A-type after freeze-thawing process. Meanwhile, the peak, though, final and setback viscosity, pasting temperature, water holding capacity, transparency and hydrolysis rate of samples significantly (P< .05) increased, while the breakdown decreased with the increase of freeze-thaw numbers. However, the increased freezing temperatures from -80 degrees C to -20 degrees C had non-significantly effects on the structure with the approximate phenomenal and the physicochemical properties like thermal properties, setback, hydrolysis rate, water holding capacity, transparency and syneresis under a same freeze-thaw cycle time.