A set of 13 waxy rice genotypes pre

A set of 13 waxy rice genotypes prepared by chemical-induced mutation of rice variety TNG67 and 7
waxy rice varieties widely grown in Taiwan were compared for structural, rheological and retrogradation
characteristics of starches. Wide differences in retrogradation enthalpy (DHret), gel firmness and storage
modulus (G’ret) were observed for 2-week stored gels of 20 starches. Ratio of short-to-long amylopectin
chains was significantly higher (p < 0.05) in starches from mutant genotypes than in commercial varieties.
DHret and G’ret of starch pastes stored over 4 weeks showed stronger correlation with amylopectin
chain-profile compared to those stored for 2 weeks. Amount of long amylopectin chains was correlated
positively (p < 0.05) with DHret and gel firmness. Overall, ratio of short-to-long amylopectin chains
affected almost all the rheological and retrogradation parameters. Results of this study can be useful to
plant breeders and food industry for quality improvement and selection of waxy rice mutants for various
applications.