KINETIC ANALYSIS OF HYDRATION AND GELATINIZATION PROCESSES DURING PARBOILING OF PADDY FOR END POINT ESTIMATION

摘要

Kinetic data on the progress of hydration and gelatinization processes, obtained duringsoaking of paddy and pressure steaming of hydrated paddy were used to fit to kinetic equations in orderto develop a predictive model for estimation of end point for paddy parboiling process. Experimental datawere produced from moisture measurement during soaking of paddy in isothermal conditions at threetemperatures (40, 50 and 60oC), and chemical measurement of degree of gelatinization during steaming atdifferent pressures i.e., 1-3 bar; for two local paddy varieties.Models tested for hydration kineticmodeling are Peleg equation, exponential equation and second order diffusion equation, whereas modeltested for gelatinization kinetic is the first order reaction equation.Based on the calibrated model the timefor reaching 30% of moisture content during hydration for chokuwa paddy was estimated as 2.1 h at 40?C, whereas steaming timeat 1 bar was estimated as 60 minutes.