A study of the retrogradation process in five Argentine rice starches

ITURRIAGA L.; LOPEZ DE MISHIMA B.; AÑÓN M.C.

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2010 vol. 43 p. 670 - 674

0023-6438

Rate of the retrogradation process of five new argentine genotypes rice starches with different amylase contents and gelatinization temperatures during storage at 4.5 _ 0.5 _C was studied using differential scanning calorimetry (DSC). Significant differences were not found among transition temperatures, i.e., T0 (onset temperature), Tp (peak temperature) and Tc (conclusion temperature), of non-waxy genotypes when studied using DSC. An increased retrogradation enthalpy (DH, mJ/mg) with the storage time occurred with all non-waxy samples. The waxy genotype, W4109, did not show a retrogradation peak for the period under study. Genotypes with high total amylose content (TAM) retrograded more than those with lower content. The kinetic parameters ‘‘k’’ and ‘‘n’’ were evaluated using the Avrami model appearing to be related to the water-soluble amylose (SAM) content. Relationship between the retrogradation degree (%R) and the water-insoluble amylose (IAM) content was found. Gelatinization temperature of the starch (TG) seemed to affect the retrogradation rate