1996 Volume 1996 Issue 5 Pages 477-482
DSC (differential scanning calorimetry) and X-ray diffraction have been used for study of retrogradation of waxy corn starch. DSC measurments were performed in the temperature ranges of-15 °C to 15°C and 30 °C to 100 °C. For a waxy corn starch solution, a sharp endothermic peak was detected at about 0 °C immediately after gelatinization, and no other endothermic peaks were confirmed. After the solution was retrograded, a re-gelatinization endothermic peak was observed, and the endothermic peak at 0 °C was separated into two peaks. This result and the endothermic peak which is observed in the re gelatinization process were related to each other, and these are regarded as a result of the retrogradation. For refrigerated samples at -18 °C, no endothemic peak to be attributed to retrogradation was detected even after 72 days. X-Ray powder diffraction of the material obtained from the retrograded waxy corn starch solution, by precipitating with acetone, indicated that the diffraction patterns can be attributed to a crystalline B-forms. While, the heat of re-gelatinizetion on the basis of dry starch was approximately constant, this fact suggests that the mechanism of retrogradation may not be influenced by the concentration of solution. From these results, we propose that the waxy corn starch molecular structure can be attributed to gelatinization and retrogradation.
This article cannot obtain the latest cited-by information.
