scholarly journals Moisture sorption isotherms of castor beans. Part 2: Thermodynamic properties

2016 ◽  
Vol 20 (8) ◽  
pp. 757-762 ◽  
Author(s):  
André L. D. Goneli ◽  
Paulo C. Corrêa ◽  
Gabriel H. H. de Oliveira ◽  
Ana P. L. R. de Oliveira ◽  
Roberto C. Orlando
Keyword(s):  
Thermodynamic Properties ◽  
Water Sorption ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Agricultural Products ◽  
Salt Solutions ◽  
Abstract Knowledge ◽  
Differential Enthalpy ◽  
Moisture Sorption Isotherms ◽  
Humidity Environment

ABSTRACT Knowledge on the water sorption within agricultural products is extremely important for decision making during post-harvest procedures. In order to improve this knowledge, thermodynamic properties regarding water sorption provide useful data. Thermodynamic properties of castor beans, related to sorption, were determined. Static gravimetric technique under different conditions of temperature (25, 35, 45 and 55 ± 1 °C) was used. Saturated salt solutions in the range of 37-87% ± 2% were utilized to create the required controlled humidity environment. After the sorption procedure, differential enthalpy, differential entropy and Gibbs free energy of this process were calculated and decreased with increased values of equilibrium moisture content.

Moisture sorption isotherms of chitosan-glycerol films: Thermodynamic properties and microstructure

2018 ◽  
Vol 22 ◽  
pp. 170-177 ◽  
Author(s):  
Micheli L. Monte ◽  
Matheus L. Moreno ◽  
Janaina Senna ◽  
Leonardo S. Arrieche ◽  
Luiz A.A. Pinto
Keyword(s):  
Thermodynamic Properties ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Moisture Sorption Isotherms

Moisture sorption isotherms and thermodynamic properties of Jack pine and palm wood: Comparative study

2014 ◽  
Vol 56 ◽  
pp. 200-210 ◽  
Author(s):  
Sahbi Ouertani ◽  
Soufien Azzouz ◽  
Lamine Hassini ◽  
Ahmed Koubaa ◽  
Ali Belghith
Keyword(s):  
Thermodynamic Properties ◽  
Comparative Study ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Jack Pine ◽  
Moisture Sorption Isotherms

scholarly journals Modelling the moisture sorption isotherms of Roselle (Hibiscus sabdariffa L.) in the temperature range of 5–35 °C

2013 ◽  
Vol 61 (6) ◽  
pp. 1769-1777 ◽  
Author(s):  
Jitka Langová ◽  
Donludee Jaisut ◽  
Ratiya Thuwapanichayanan ◽  
Charotorn Phowong ◽  
Jiří Štencl ◽  
...  
Keyword(s):  
Moisture Content ◽  
Water Sorption ◽  
Structural Changes ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Ambient Air ◽  
Point Of View ◽  
Hibiscus Sabdariffa ◽  
Adsorption And Desorption ◽  
Moisture Sorption Isotherms

Water sorption tests of Roselle (Hibiscus sabdariffa L.) carried out under laboratory conditions are presented together with mathematical analyses of the moisture sorption isotherms (MSI’s). Moisture equilibrium data for adsorption and desorption of water from Roselle powder were investigated at near ambient air temperatures in the range of 5 and 35 °C and water activity (Aw) ranging from 0.11 to 0.97. The manometric method has been used for water sorption tests. Models for MSI’s are exponential equations. Coefficients of determination are 0.998 and 0.996 (for adsorption and desorption at 5 °C, respectively), 0.998 and 0.999 (for adsorption and desorption at 20 °C, respectively), and 0.998 and 0.999 (for adsorption and desorption at 35 °C, respectively). The equilibrium moisture content (EMC) of Roselle samples increased with an increase of Aw at a constant temperature both for adsorption and desorption. Adsorption curve equates to desorption curve at higher temperatures of tests carried out. Critical values of EMC of samples tested corresponding to the Aw equal to 0.6 were between 13.401% moisture content wet basis (MC w.b.) and 15.934% MC (w.b.) for moisture adsorption and desorption, respectively. These values are useful for storing conditions optimisation from point of view microorganisms grow and structural changes analyses. Crystal structure changes were observed during adsorption and desorption in the microscope, too. It was found out glass transition in dependence on the water content of samples tested.

Moisture Sorption Isotherms, Thermodynamic Properties, and Glass Transition of Pears and Apples

2012 ◽  
Vol 30 (13) ◽  
pp. 1397-1406 ◽  
Author(s):  
Nadia Djendoubi Mrad ◽  
Catherine Bonazzi ◽  
Nourhène Boudhrioua ◽  
Nabil Kechaou ◽  
Francis Courtois
Keyword(s):  
Glass Transition ◽  
Thermodynamic Properties ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Moisture Sorption Isotherms

Thermodynamic Analysis of Water Vapour Sorption of Edible Starch Based Films

2003 ◽  
Vol 9 (2) ◽  
pp. 115-121 ◽  
Author(s):  
M. A. Bertuzzi ◽  
M. Armada ◽  
J. C. Gottifredi
Keyword(s):  
Water Sorption ◽  
Corn Starch ◽  
Gravimetric Method ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Sorption Process ◽  
Water Vapour Sorption ◽  
Bet Model ◽  
Moisture Sorption Isotherms ◽  
High Amylose

Moisture sorption isotherms of high amylose corn starch (HACS) films at 5, 25, 35 and 45 °C within an approximate water activity ( aw) range of 0.11-0.85 were obtained using a static gravimetric method. HACS films fitted a type III BET model at all temperatures studied. Water sorption process in high amylose based films was exothermic within the range of water activities investigated. There was a continuous decrease of the affinity between film sorbed structure with moisture as water content increased. Negative values of Δ G in the whole range of moisture content studied were indicative of a spontaneous process. The entropy curve exhibited a well-defined minimum corresponding at the completion of the monolayer.

scholarly journals Moisture sorption isotherms and thermodynamic properties of whole black peppercorns (Piper nigrum L.)

LWT ◽  
2015 ◽  
Vol 64 (1) ◽  
pp. 177-188 ◽  
Author(s):  
Pratheeba Yogendrarajah ◽  
Simbarashe Samapundo ◽  
Frank Devlieghere ◽  
Sarah De Saeger ◽  
Bruno De Meulenaer
Keyword(s):  
Thermodynamic Properties ◽  
Sorption Isotherms ◽  
Moisture Sorption ◽  
Piper Nigrum ◽  
Moisture Sorption Isotherms
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