Thermodynamic analysis for the hygroscopic behavior of barley seeds (Hordeum vulgare L.)

被引:0
作者
Dias Maia G. [1 ]
Albini G. [1 ]
Teixeira Freire J. [1 ]
机构
[1] Drying Center of Pastes, Suspensions and Seeds, Federal University of São Carlos, Department of Chemical Engineering, Via Washington Luis, Km235, P.O. Box 676, São Carlos, 13565-905, SP
关键词
Barley; Differential entropy of sorption; GAB equation; Net isosteric heat; Thermodynamic analysis;
D O I
10.11301/jsfe.17.131
中图分类号
学科分类号
摘要
Sorption isotherms aid the analysis of different classes of water to determine the energy required to remove this moisture from seeds. The goal of the present study was to determine and analyze the sorption isotherms for barley seeds. Qualitative and quantitative thermodynamic analysis was performed by GAB model parameters and by calculating the net isosteric heat and differential entropy of sorption. The GAB model successfully described the experimental data. The monolayer equilibrium moisture decreased from 0.092 kg・kg-1 to 0.057 kg・kg-1 as the temperature increased from 15 to 50°C. The net isosteric heat of sorption for the monolayer calculated by the GAB equation parameters exhibited good agreement with that calculated by the Clausius-Clapeyron equation, with values of 2433.0 and 2233.7 kJ・kg-1, respectively. Environmental conditions may have affected the formation of the adsorption sites within the seeds endosperm when compared with literature data. The use of empirical models to fit sorption isotherms may mischaracterize the thermodynamic analysis of the monolayer. © 2016 Japan Society for Food Engineering.
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页码:131 / 138
页数:7
相关论文
共 21 条
[1]  
Briggs D.E., Malts and Malting (Blackie Academic & Professional), (1998)
[2]  
Kunze W., Technology Brewing and Malting (VLB), (2004)
[3]  
Kiranoudis C.T., Maroulis Z.B., Tsami E., Marinos-Kouris D., Equilibrium moisture content and heat of desorp-tion of some vegetables, J. Food Eng., 20, pp. 55-74, (1993)
[4]  
Vemuganti G.R., Pfost H.B., Chung D.S., Burroughs R., Some Properties of Cereal Grains, Food Legumes and Oil-Seeds (Hygroscopic, Thermal, Physical) Affecting Storage and Drying (Food & Feed Grain Institute), (1980)
[5]  
Sun D., Woods J.L., Low temperature moisture transfer characteristics of barley: Thin-layer models and equilibrium isotherms, J. Agric. Eng. Res., 59, pp. 273-282, (1994)
[6]  
Basunia M.A., Abe T., Adsorption isotherms of barley at low and high temperatures, J. of Food Eng., 66, pp. 129-136, (2005)
[7]  
Neagu C., Tofan C., Borda D., Mathematical models for moisture sorption isotherms of barley and wheat, J. Agroalimentary Proc. and Techs, 15, (2009)
[8]  
Anderson R.B., Modifications of the Brunauer, Emmett and Teller equation, J. Am. Chem. Soc., 68, pp. 686-691, (1948)
[9]  
Thitisaksakul M., Jimenez R.C., Arias M.C., Beckles D.M., Effects of environmental factors on cereal starch biosynthe-sis and composition, J. Cereal Sci, 56, pp. 67-80, (2012)
[10]  
Langmuir I., The adsorption of gases on plane surfaces of glass, mica and platinum, J. Am. Chem. Soc, 40, pp. 1361-1403, (1918)