MOISTURE SORPTION STUDY ON NIGERIAN FOODS: MAIZE and SORGHUM |
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| Authors: | PA SOPADE ES AJISEGIRI |
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| Affiliation: | Food Technology Section Department of Applied Sciences University of Technology, P.M.B. Services, Lae, Papua New Guinea;Department of Agricultural Engineering Federal University of Technology, Minna, Nigeria |
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| Abstract: | Adsorption-desorption behavior of maize and sorghum between aw= 0.10–0.98 at temperatures of 20, 25 and 40C was studied. the grains exhibited type II sorption isotherm. the sorption data were analyzed using six sorption models and the coefficients of determination were between 0.6965–0.9994. the Caurie model gave the poorest fit and the Henderson model the best. Some models were better for adsorption than for desorption. the GAB and BET monolayer moisture contents were not significantly (p > 0.05) different. Monolayer values were temperature-dependent with activation energy from 1.36–10.08 MJ/mol and the maize monolayer values exhibited the highest sensitivity to temperature. Heat of sorption was obtained by applying Claussius-Clapeyron equation to the sorption isotherms at the three temperatures. the heat of sorption decreased with an increase in moisture content and an exponential equation was used to describe the relationship. the processing and storage consequences of this information were discussed. |
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