Equilibrium sorption isotherms and thermodynamic properties of starch and gluten
A modification of the GAB isotherm (Guggenheim-Anderson-De Boer) is proposed in order to correlate the sorption data for water activities higher than 0.9. The proposed isotherm retains the desirable properties of the GAB isotherm, i.e. good fitting in the range of aw between 0.05 and 0.80, and also...
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1999
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02608774_v40_n4_p287_Viollaz http://hdl.handle.net/20.500.12110/paper_02608774_v40_n4_p287_Viollaz |
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paper:paper_02608774_v40_n4_p287_Viollaz2023-06-08T15:22:28Z Equilibrium sorption isotherms and thermodynamic properties of starch and gluten Adsorption isotherms Drying Moisture Sorption Starch Thermal effects Thermodynamic properties Isosteric heat Food processing Solanum tuberosum A modification of the GAB isotherm (Guggenheim-Anderson-De Boer) is proposed in order to correlate the sorption data for water activities higher than 0.9. The proposed isotherm retains the desirable properties of the GAB isotherm, i.e. good fitting in the range of aw between 0.05 and 0.80, and also provides a noticeable improvement in the fitting quality for high values of aw, by introducing a new term with an additional constant. Sorption data for native potato starch and gluten at different temperatures (2 °C, 20 °C, 40 °C and 67 °C) were well correlated for the whole aw range. For starch at 67 °C, the values of the constants of the proposed equation do not follow the same tendency obtained for lower temperatures, suggesting that the structure of the material could be changed due to the high temperature. The proposed isotherm can be of interest in the area of drying given that there are few isotherms that accurately represent sorption data at different temperatures in the zone of high aw. Also, it can be useful to predict other thermodynamic functions. In addition, a new procedure is proposed to determine the isosteric heat by using a second order polynomial for representing the variation of moisture as a function of temperature at a fixed water activity. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02608774_v40_n4_p287_Viollaz http://hdl.handle.net/20.500.12110/paper_02608774_v40_n4_p287_Viollaz |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Adsorption isotherms Drying Moisture Sorption Starch Thermal effects Thermodynamic properties Isosteric heat Food processing Solanum tuberosum |
| spellingShingle |
Adsorption isotherms Drying Moisture Sorption Starch Thermal effects Thermodynamic properties Isosteric heat Food processing Solanum tuberosum Equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| topic_facet |
Adsorption isotherms Drying Moisture Sorption Starch Thermal effects Thermodynamic properties Isosteric heat Food processing Solanum tuberosum |
| description |
A modification of the GAB isotherm (Guggenheim-Anderson-De Boer) is proposed in order to correlate the sorption data for water activities higher than 0.9. The proposed isotherm retains the desirable properties of the GAB isotherm, i.e. good fitting in the range of aw between 0.05 and 0.80, and also provides a noticeable improvement in the fitting quality for high values of aw, by introducing a new term with an additional constant. Sorption data for native potato starch and gluten at different temperatures (2 °C, 20 °C, 40 °C and 67 °C) were well correlated for the whole aw range. For starch at 67 °C, the values of the constants of the proposed equation do not follow the same tendency obtained for lower temperatures, suggesting that the structure of the material could be changed due to the high temperature. The proposed isotherm can be of interest in the area of drying given that there are few isotherms that accurately represent sorption data at different temperatures in the zone of high aw. Also, it can be useful to predict other thermodynamic functions. In addition, a new procedure is proposed to determine the isosteric heat by using a second order polynomial for representing the variation of moisture as a function of temperature at a fixed water activity. |
| title |
Equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| title_short |
Equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| title_full |
Equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| title_fullStr |
Equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| title_full_unstemmed |
Equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| title_sort |
equilibrium sorption isotherms and thermodynamic properties of starch and gluten |
| publishDate |
1999 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02608774_v40_n4_p287_Viollaz http://hdl.handle.net/20.500.12110/paper_02608774_v40_n4_p287_Viollaz |
| _version_ |
1768541986159067136 |