title: Moisture Sorption and Thermodynamic Properties of Vacuum-Dried Capsosiphon fulvescens Powder.
abstract: The moisture sorption isotherms of vacuum-dried edible green alga (Capsosiphon fulvescens) powders were determined at 25, 35, and 45°C and water activity (a w) in the range of 0.11~0.94. An inversion effect of temperature was found at high water activity (>0.75). Various mathematical models were fitted to the experimental data, and Brunauer, Emmett, and Teller model was found to be the most suitable model describing the relationship between equilibrium moisture content and water activity (<0.45). Henderson model could also provide excellent agreement between the experimental and predicted values despite of the intersection point. Net isosteric heat of adsorption decreased from 15.77 to 9.08 kJ/mol with an increase in equilibrium moisture content from 0.055 to 0.090 kg H2O/kg solids. The isokinetic temperature (T β) was 434.79 K, at which all the adsorption reactions took place at the same rate. The enthalpy-entropy compensation suggested that the mechanism of the adsorption process was shown to be enthalpy-driven.
authors.affiliation: Department of Food Science and Engineering, Daegu University, Gyeongbuk 38453, Korea.
authors.forename: Li
authors.initials: L
authors.lastname: Zuo
authors.affiliation: Department of Food Engineering, Mokpo National University, Jeonnam 58554, Korea.
authors.forename: Jong-Whan
authors.initials: JW
authors.lastname: Rhim
authors.affiliation: Department of Food Science and Engineering, Daegu University, Gyeongbuk 38453, Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
keywords: Capsosiphon fulvescens; moisture sorption; thermodynamic properties; vacuum-dried