Gelatinization Characterization of Rice Starches

米澱粉的糊化特性

賴鳴鳳(Vivian M. F. Lai) ； 呂政義(Cheng-Yi Lii)

《中央研究院化學研究所集刊》 47期 (2000/08) Pp. 55-64

https://doi.org/10.6522/BICAS.2000.47.6

並列摘要

The thermal properties during gelatinization of 33 wt% starches were analyzed by DSC with various heating rates (β= 5-15 °C/min). By using 11 varieties of starches from indica, japonica and waxy rice, the roles of amylose content and granular property during gelatinization were investigated. The average onset (T_o), peak (T_p) and conclusion (T_c) temperatures for gelatinization of the starches wetted for 24 h were in the ranges of 56.4-71.1 °C, 61.4-74.9 °C and 68.8-82.0 °C, respectively. The average gelatinization temperature range (GT) appeared to be: indica (10.1-13.0 °C) ≤ japonica (12.8-14.6 °C) ＜ waxy variety (17.8-19.7 °C), contrary to the order for peak-shape index (S = ∆H/GT). And , the enthalpy changes (∆H) of gelatinization for all starch systems ranged from 10.2 to 14.6 J/g. Amylose content (AM%) and water solubility showed significantly negative correlations with GT or ∆H, but not with T_o, T_p and T_c; while swelling power did positively with GT. The heating- rate dependencies of the thermal parameters (dT_o/dβ, dT_p/dβ, dT_c/dβ, dGT/dβ, d∆H/dβ and dS/dβ) and their calculated values as 13 = 0 (T_(o0), T_(p0), T_(c0), GT_0, ∆H_0 and S_0) appeared to change with starch variety. Values of dT_p/dβ, GT_0, and S_0 were also significantly correlated with AM% and swelling power. Generally. the lower the heating rate used in DSC analysis, the more significant was the correlation between GT and AM% or water solubility, or between thermal parameters. However, higher heating rates, such as 15°C/min, would be more suitable for observation of AM% effects on ∆H.