Water absorption and starch gelatinization in whole rice grain during soaking
Hydration of rough rice grain in hot water as a function of time was studied at temperature range 25-90 °C. A simple model which considers simultaneous unsteady-state water diffusion and first-order irreversible water-starch reaction phenomenon, was used to evaluate the kinetics parameters from expe...
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| Autores principales: | , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00236438_v40_n2_p313_Bello |
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| Sumario: | Hydration of rough rice grain in hot water as a function of time was studied at temperature range 25-90 °C. A simple model which considers simultaneous unsteady-state water diffusion and first-order irreversible water-starch reaction phenomenon, was used to evaluate the kinetics parameters from experimental curves. The values of the diffusion coefficients and reaction rate constants were between 1.40×10-11 and 9.36×10-11 m2 s-1 and 2.29×10-10 and 3.72×10-5 s-1, respectively. Both parameters followed a Arrhenius-type equation with distinct activation energies below and above a break temperature of 60 °C. It was 25.4 and 289.3 kJ mol-1 for the activation energies of diffusion and reaction, respectively, below 60 °C. Above this temperature the respective values of the activation energies of diffusion and reaction were 30.0 and 16.6 kJ mol-1. This break temperature was in agreement with the gelatinization temperature determined experimentally. © 2005 Swiss Society of Food Science and Technology. |
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