CHANGES WITH RETROGRADATION OF MECHANICAL AND TEXTURAL PROPERTIES OF GELS FROM VARIOUS STARCHES

Gels were prepared from various starch species at three different conc entrations for each starch species. The gels were stored at 5 degrees C for 1 to 30 days, and characterized in terms of mechanical parameter s measured by a compression-decompression test. Compression work and r upture force increased gradually with storage period. Resiliency and c ompressibility increased and decreased, respectively, most significant ly in the first 5 to 10 days. Changes in mechanical properties of the gels during storage were different among starch species. Changes in te xtural properties of the gels during storage were evaluated using thre e-dimensional representation of the gels through factor analysis of in strumental data and calculation of factor scores. The gels were also e xamined for degree of gelatinization using an enzymatic method. From a regression analysis of those data, the relationship of the change in degree of gelatinization to change in mechanical properties was observ ed. Resiliency was found to be the most correlative property.