title: Effect of annealing temperature on gelatinization of rice starch suspension as studied by rheological and thermal measurements.
abstract: The effect of annealing temperature (Ta) on the rheological behavior of 10 wt % rice starch suspension was investigated by the dynamic viscoelasticity, the differential scanning calorimetry (DSC), and the amount of leached out amylose and the swelling ratio of starch suspension. The rheological behaviors of the annealed samples are classified into three types in terms of Ta: Ta1, 48 and 55 degrees C, which are much lower than the gelatinization temperature, Tgel (=62 degrees C); Ta2, 58, 60, and 62 degrees C, which are almost the same as Tgel; and Ta3, 65, 68, 70, and 73 degrees C, which are much higher than Tgel. For the samples annealed at Ta2, the onset temperature of the storage and the loss moduli, G' and G'', increased with increasing T(a), and G' and G" in the temperature range from 65 to 90 degrees C gradually increased though smaller than those for the nonannealed sample, the control. This can be understood by the partial gelatinization; i.e., the leached out amylose prevents further amylose from leaching out. The rheological property of the samples annealed at Ta1 is not so different from that of the control, and the samples annealed at Ta3 are almost gelatinized. The rheological behavior of starch suspension can be controlled by Ta.
authors.affiliation: Department of Food Science and Nutrition, Nara Women's University, Kitauoyanishi-machi, Nara 630-8263, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Tsutsui
authors.forename: Keiko
authors.initials: K
authors.lastname: Katsuta
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Matoba
authors.forename: Makoto
authors.initials: M
authors.lastname: Takemasa
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Nishinari
mesh_terms: D000688:Amylose / Q000737:chemistry; D004548:Elasticity; D005782:Gels / Q000737:chemistry; D006358:Hot Temperature; D012275:Oryza / Q000737:chemistry*; D012212:Rheology; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D005782:Gels; D013213:Starch; D000688:Amylose