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Vitázek, I., and J. Havelka. "Sorption isotherms of agricultural products." Research in Agricultural Engineering 60, Special Issue (2014): S52—S56. http://dx.doi.org/10.17221/35/2013-rae.
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The aim of the paper is to expand the theory of sorption and equilibrium moisture contents as well as to present the methodology of developing two types of sorption isotherms – I and II. The attention is also paid to the importance of the isotherms in the thermodynamics of drying and in the process of storage of agricultural products. Presented methodology of obtaining the isotherms is based on selected equations of the theory of adsorption and on the results of experimental measurements of equilibrium moisture content. Definition of the new isotherm II is introduced as dependence of equilibrium moisture content dry basis on time at constant temperature, constant relative moisture of the ambient air and stable biological properties (e.g. germination). The results show following graphic dependences: isothermal distort plane; sorption isotherm I of maize grains at various temperatures; moisture loss rate in dependence on time and sorption isotherm II. These theoretical dependences supported by experimental measurements broaden the scope of the theory of sorption and may be successfully applied in long-term storage of maize grains.
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Setyawan, N., Clarissa, E. Y. Purwani, and A. Budiyanto. "Moisture Sorption Isotherm Characteristic of Composite Flour (Cassava, Rice, Sorghum, and Sago) at Various Fitting Models." IOP Conference Series: Earth and Environmental Science 1024, no. 1 (2022): 012053. http://dx.doi.org/10.1088/1755-1315/1024/1/012053.
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Abstract Cassava, rice, sorghum, and sago flour can be mixed into composite flour. The properties of composite flour easily absorb water, so it is necessary to know the isotherm sorption through various models, such as Brunauer-Emmet-Teller (BET), Oswin, Hasley, Henderson, Caurie, Chen-Clayton and Guggenheim, Anderson, and Boer (GAB). Information on the sorption properties of foods is of great importance in food dehydration, especially in the quantitative approach to predicting the shelf life of dried foods such as flour. This research aims to determine the sorption isotherms of composite flour experimentally and evaluate the suitability of various mathematical models for fitting the isotherms. Samples were stored at 28 ± 2 ° C with various water activity conditions (aw 0.05-0.97). The results showed that the moisture sorption isotherm of composite flour followed the sigmoid type II behavior frequently found in dry food products. The behavior of composite flour (Formula A and C) equilibrium moisture in the study was satisfactorily described by means of the moisture sorption isotherm of Oswin model with MRD value respectively is 5.64 and 4.93. While the behavior equilibrium moisture for other flour (Formula B and D) was precisely depicted by means of the moisture sorption isotherm of Chen Clayton model with MRD value respectively is 5.08 and 3.39.
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Zhou, Z., and K. P. Zubarev. "The use of sorption and excess sorption isotherm in the mathematical modeling of the unsteady-state heat and humidity regime of the building envelope." Journal of Physics: Conference Series 2131, no. 5 (2021): 052072. http://dx.doi.org/10.1088/1742-6596/2131/5/052072.
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Abstract In the given article the development of the moisture transfer equation based on the theory of moisture potential is considered. The task of combined heat and moisture transfer is one of the most complicated tasks in the building thermal physics field. The classical equations of moisture transfer by K.F. Fokin representing the transfer of moisture under the action of partial transfer potentials - the gradient of the partial pressure of water vapor and the gradient of humidity F - are listed. The possibility of uniform accounting of the combined water vapor transfer on the basis of the moisture potential F is described. The sorption isotherm for aerated concrete is constructed in accordance with the experiment carried out in a desiccator with an aqueous solution of sulfuric acid. A new equation of moisture transfer which takes into account moistening with vaporous moisture in the sorption zone of moisture and liquid moisture in the excess sorption zone of moisture is derived. In order to simplify the work with the obtained equation a new value of the relative potential capacity is introduced. A graph construction of sorption and excess sorption isotherms which are obtained using an analytical expression for the relative potential capacity is proposed. In the sorption zone of humidification the sorption and excess sorption isotherms coincide with the classical sorption isotherm. Meanwhile, in the excess sorption zone of humidification the sorption and excess sorption isotherms depend on temperature.
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Mitrevski, Vangelce, and Cvetanka Mitrevska. "Mathematical modelling of moisture sorption isotherms of some fruits." INTERNATIONAL JOURNAL OF THERMAL-FLUID ENGINEERING AND MODERN ENERGETICS 1, no. 1 (2022): 74–82. http://dx.doi.org/10.51558/2831-0527.2022.1.1.74.
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The moisture sorption isotherms of some fruits namely pear and quince were determined at 15, 30, 45 and 60oC over a range of water activity from 0.110 to 0.920 using the standard, static-gravimetric method. The experimental sorption data were fitted with generated three-parameter sorption isotherm models on Mitrevski et al., and the referent Anderson model known in the scientific and engineering literature as Guggenheim-Anderson-de Boer (GAB) model. In order to find which models give the best results, large number of numerical experiments was performed. After that, several statistical criteria for estimation and selection of the best sorption isotherm model was used. The performed statistical analysis shows that the generated three-parameter model from Mitrevski et al. gave the best fit to the sorption data of pear and quince than the referent three-parameter Anderson model. Keywords: Sorption isotherms Pear Quince Statistical criteria
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Blahovec, J., and S. Yanniotis. "'GAB' generalised equation as a basis for sorption spectral analysis." Czech Journal of Food Sciences 28, No. 5 (2010): 345–54. http://dx.doi.org/10.17221/146/2009-cjfs.
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The transformed sorption isotherm (represented by the ratio of water activity and moisture content (d.b.) versus water activity) was approximated by polynomials of 2<sup>nd</sup>&ndash;<sup>6th</sup> order. It is shown that the relative derivative of the transformed equation expresses the deviation of the sorption isotherm from the linear relationship between the moisture content and water activity either to the sorption isotherm of the Lagmuir's type (the positive relative derivative) or to the sorption isotherm of the solution type (the negative relative derivative). The relative derivative plotted versus water activity then serves as a spectral indicator of the prevailing sorption mechanism. Spectral analysis is applied to sorption isotherms of potato and wheat starches and some fruits and vegetables. For starches, the differences in the spectral indicator between resorption and desorption as well as the effect of starch processing (gelatinisation and hydrolysis) on spectral analysis are discussed. The role of spectral analysis in the assessment of the prevailing sorption mechanism (surface vs solution sorption) is demonstrated for fruits and vegetables.
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Chen, Chiachung. "Validation of the Component Model for Prediction of Moisture Sorption Isotherms of Two Herbs and other Products." Foods 8, no. 6 (2019): 191. http://dx.doi.org/10.3390/foods8060191.
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Sorption isotherm is an essential property for the processing of biological materials. In this study, a component model for the prediction of the sorption isotherm was evaluated. In order to validate this component model, the moisture sorption isotherms for Chrysanthemum morifolium flowers and the orchid Anoectochilus formosanus Hayata were determined. The sorption isotherm was measured by using the equilibrium relative humidity technique for five temperatures. Seven sorption isotherm models were selected with four quantitative criteria and residual plots to evaluate fitting ability and prediction performance for these products. The results indicated that the sorption temperature did not significantly affect the adsorption isotherm. The Caurie and Henderson equations could be used for C. morifolium flowers and A. formosanus Hayata. The isotherm data of raw bamboo, elecampe and three varieties of corn kernels from the literature were adopted to validate the component model. Comparing with the predicted values of component values and actual isotherm moisture, the component model has good predictive ability at the aw range smaller than 0.7. Considering the practical application, the aw range below 0.7 is the main range for the processing of agricultural products, and the predictive values of this component model could be helpful for food engineering and for the food industry.
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Rachtanapun, Pornchai, and R. Suriyatem. "Prediction Models for Moisture Sorption Isotherms of Soy Protein Isolate/Carboxymethyl Chitosan/Oleic Acid Blend Films." Advanced Materials Research 506 (April 2012): 595–98. http://dx.doi.org/10.4028/www.scientific.net/amr.506.595.
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Soy protein isolate/carboxymethyl chitosan/oleic acid (SPI/CMCH/O) blend films were prepared by solution casting. The effect of various oleic acid content (0, 2.5, 5.0, 10.0, 20.0 pph of SPI and CMCH) on water sorption isotherm of SPI/CMCH base film was investigated. The sorption isotherm of SPI/CMCH/O blend films was evaluated at serveral relative humidity (0, 16, 35, 55 and 76% RH), at 25±1°C. The isotherms showed equilibrium moisture content (%EMC) of SPI/CMCH/O blend films decreased when oleic acid content increased. Understanding of sorption isotherms is an importance for prediction of moisture sorption properties of films via moisture sorption empirical models. Guggenheim-Anderson-de Boer (GAB), BrunauerEmmettTeller (BET) and Oswin sorption models were tested to fit the experimental data. The root mean squares (RMS) of GAB, BET and Oswin were in the range of 68.60-87.02, 22.86-79.38 and 694.78-3797.23, respectively. BET model was found to be the better-fitted model for SPI/CMCH/O blend films at 25±1°C.
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Suriyatem, Rungsiri, and Pornchai Rachtanapun. "Prediction Modeling for Moisture Sorption Isotherms of Rice Starch/Carboxymethyl Cellulose from Durian Rind Blend Films." Applied Mechanics and Materials 431 (October 2013): 32–36. http://dx.doi.org/10.4028/www.scientific.net/amm.431.32.
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Rice starch/carboxymethyl cellulose from durian rind (RS/CMCd) blend films were prepared by solution casting. The effect of different ratios between rice starch and CMCd (100:0, 88:12, 67:33, 50:50, 33:67, 12:88 and 0:100) on moisture sorption isotherm of blend films was investigated. The sorption isotherm of RS/CMCd blend films was determined at various relative humidity (RH) at 25°C. The isotherm curves revealed that the highest equilibrium moisture content (EMC) was obtained from CMCd film, at aw=85. Knowledge of sorption isotherms is important to predict the moisture sorption properties of the filmsviamoisture sorption empirical models. The Lewicki, Peleg, Guggenheim-Anderson-deBoer (GAB), BrunauerEmmettTeller (BET), and Oswin models were tested to fit the experimental data. The root mean squares percentage error (%RMS) of Lewicki, Peleg, GAB, BET and Oswin was in the range of 5.3-83.1, 2.2-20.0, 6.9-20.2, 3.4-26.4 and 4.7-41.2, respectively. The Peleg model was found to be the best fitted model for RS/CMCd blend films.
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Alfiah, Mutiara Nur, Sri Hartini, and Margareta Novian Cahyanti. "MATHEMATICAL MODELS AND THERMODYNAMIC PROPERTIES OF MOISTURE SORPTION ISOTHERMS OF FERMENTED CASSAVA FLOUR BY RED YEAST RICE." ALCHEMY Jurnal Penelitian Kimia 13, no. 1 (2017): 29. http://dx.doi.org/10.20961/alchemy.13.1.4326.29-40.
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<p>This research aims to determine moisture sorption isotherm curves, moisture sorption isotherm models and thermodynamic properties of fermented cassava flour by red yeast rice. The moisture sorption isotherm model used are Guggenheim Anderson deBoer (GAB), Brunauer Emmet Teller (BET) and Caurie. Meanwhile, the test of modelling accuray by Mean Relative Deviation (MRD) and Root Mean Square Error (RMSE). The thermodynamic properties, i.e., enthalpy and entropy were calculated by Clausius - Clapeyron equation. The result shows that the moisture sorption isotherm curve on fermented cassava flour in a sigmoid form (type II). The GAB model is the best model for moisture sorption isotherm of fermented cassava flour by red yeast rice. The MRD and RMSE values at 30˚C, 35˚C and 40˚C are 3.12%, 2.71%, 3.81%, and 1.01, 0.35, 0.42, respectively. The monolayer moisture content at 30˚C, 35˚C and 40˚C are 6.61%, 6.27% and 6.91%, based on GAB model. Meanwhile, when the BET model was used, the monolayer moisture content are 4.92%, 4.86% and 5.19%, while by Caurie model are 6.37%, 6.18% and 5.30%, at 30˚C, 35˚C and 40˚C, respectively. The enthalpy and entropy of water sorption process were decreased when moisture content increased.</p>
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Alfiah, Mutiara Nur, Sri Hartini, and Margareta Novian Cahyanti. "MATHEMATICAL MODELS AND THERMODYNAMIC PROPERTIES OF MOISTURE SORPTION ISOTHERMS OF FERMENTED CASSAVA FLOUR BY RED YEAST RICE." ALCHEMY Jurnal Penelitian Kimia 13, no. 1 (2017): 29. http://dx.doi.org/10.20961/alchemy.v13i1.4326.
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<p>This research aims to determine moisture sorption isotherm curves, moisture sorption isotherm models and thermodynamic properties of fermented cassava flour by red yeast rice. The moisture sorption isotherm model used are Guggenheim Anderson deBoer (GAB), Brunauer Emmet Teller (BET) and Caurie. Meanwhile, the test of modelling accuray by Mean Relative Deviation (MRD) and Root Mean Square Error (RMSE). The thermodynamic properties, i.e., enthalpy and entropy were calculated by Clausius - Clapeyron equation. The result shows that the moisture sorption isotherm curve on fermented cassava flour in a sigmoid form (type II). The GAB model is the best model for moisture sorption isotherm of fermented cassava flour by red yeast rice. The MRD and RMSE values at 30˚C, 35˚C and 40˚C are 3.12%, 2.71%, 3.81%, and 1.01, 0.35, 0.42, respectively. The monolayer moisture content at 30˚C, 35˚C and 40˚C are 6.61%, 6.27% and 6.91%, based on GAB model. Meanwhile, when the BET model was used, the monolayer moisture content are 4.92%, 4.86% and 5.19%, while by Caurie model are 6.37%, 6.18% and 5.30%, at 30˚C, 35˚C and 40˚C, respectively. The enthalpy and entropy of water sorption process were decreased when moisture content increased.</p>
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Nurhayati, Rifa, Rosi Pratiwi, Baskara Katri Anandito, Ervika Rahayu Novita, and Mukhammad Angwar. "Shelf Life Prediction of Chocomix Instant Chocolate Beverage Powder Using Accelerated Shelf Life Testing (ASLT) based on Critical Moisture Content Approach." Reaktor 18, no. 2 (2018): 63. http://dx.doi.org/10.14710/reaktor.18.2.63-70.
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Chocomix chocolate beverage powder is one of the increased value-added cocoa products by Griya Cokelat Nglanggeran. The aimed of this study to estimate the shelf life using Accelerated Shelf Life Testing (ASLT) based on critical moisture content. Results showed that critical moisture content of Chocomix was 4.01 % (db). Moisture sorption isotherm (MSI) curve of Chocomix at 28oC was type II isothermic sigmoidal with 2 curves at the ranged of water activity between 0.24 and 0.68; and the equation was y = 86.584X3 – 91.893X2 + 28.818X – 0.470. The calculation showed that estimated shelf life of Chocomix stored in 51.89 µm thick package at 28oC was 16.4 months.Keywords: chocolate powder, critical moisture content, moisture sorption isotherm, shelf life
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Nazreen, Aqila Zulaikha, Junaidah Jai, Sherif Abdulbari Ali, and Norasmah Mohamed Manshor. "Moisture Adsorption Isotherm Model for Edible Food Film Packaging – A Review." Scientific Research Journal 17, no. 2 (2020): 221. http://dx.doi.org/10.24191/srj.v17i2.10160.
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Bioplastic has been extensively studied due to its ability to replace synthetic plastics. Its biodegradability is seen as a significant advantage to be used as edible food film packaging. As a food packaging, the film should be able to retain moisture from the food and the surrounding environment. The ability of the film to retain moisture varies with the type of material the film is made of. Moisture sorption isotherms are used to study the moisture content and water activity of food or film packaging at a given temperature. There are many models to describe moisture sorption isotherm. Some researchers modified the models to account for varying temperatures. The purpose of this paper is to review types of adsorption isotherms and the most common models used for film packaging. The general and modified models are described in this paper as well as its best-fit use on film packaging. The advantages of studying adsorption isotherm include shelf-life determination, physical and chemical stability, and others.
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Lang, Qian, Vladimirs Biziks, and Holger Militz. "Water Vapor Sorption Kinetics of Beech Wood Modified with Phenol Formaldehyde Resin Oligomers." Forests 14, no. 10 (2023): 2015. http://dx.doi.org/10.3390/f14102015.
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Beech is an important tree species in Europe. This study aimed to elucidate the influence of four molecular weights of phenol formaldehyde (PF) resin (266, 286, 387, and 410 g/mol) on the sorption behavior of unmodified and modified beech wood samples using a dynamic vapor sorption (DVS) apparatus. The variations in the environmental relative humidity and moisture content (MC) of the samples were recorded, and the DVS isotherms were plotted from the equipment. During the sorption process, the MC of the modified samples decreased in comparison to that of the unmodified samples, and both apparently decreased with the increasing molecular weight of the PF resin. The DVS isotherm hysteresis plot illustrated a reduction in sorption hysteresis for the modified wood with varying PF resins compared to the unmodified samples. Based on the DVS isotherm adsorption and desorption plots, the decrease in the equilibrium of the MC can be attributed to there being fewer sorption sites in the modified samples, which exhibited the lowest hygroscopicity. Overall, the moisture sorption mechanism for both types of samples was clarified, highlighting a clear correlation between the molecular weight of the applied PF resin and its influence on moisture sorption behavior.
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JOHN, BOSCO KAWONGOLO, I. MURANGA FLORENCE, and HENSEL OLIVER. "DETERMINATION OF THE SORPTION ISOTHERMS FOR Matooke (Musa sp., AAA-EAHB)." Journal of Advances in Food Science & Technology 4, no. 2 (2017): 52–61. https://doi.org/10.5281/zenodo.1411655.
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Banana, (<em>matooke</em>) <em>Musa </em>sp<em>.</em> triploid <em>acuminate </em>genome group (AAA-EAHB) is an important crop in Uganda. <em>Matooke</em> flour contains more than 80% starch (db) which is good for both food and nonfood industrial applications, however, there is no information on moisture sorption isotherm for<em> matooke</em>. The main objective of the study was to establish the moisture sorption isotherms for <em>matooke</em> flour in order to standardize the stability of raw <em>matooke</em> flour with respect to microbiology and shelf life. The static gravitation method recommended by COST 90 Project was used for determination of moisture sorption isotherms. <em>Matooke</em> isotherms exhibited type II curve behavior which is characteristic of foodstuffs. Among the six models fitted to describe the adsorption and desorption isotherms for <em>matooke,</em> the GAB model best described all the adsorption and desorption moisture isotherms. <em>Matooke</em> should be dried to moisture content below or equal to 10% (wb) in order to obtain a microbiologically shelf-stable dry product (<em>matooke</em> flour). The hysteresis phenomenon was exhibited by the moisture sorption isotherms for <em>matooke.</em> The isoteric heat of sorption for both adsorption and desorption isotherms increased with decreased moisture content. <em>Matooke’</em>s total isosteric heat of sorption for the adsorption and desorption isotherms ranged between 4,586 – 2,386 kJ/kg and 18,194– 2,391 kJ/kg respectively, for equilibrium moisture content from 0.3 – 0.01 (db). The minimum energy required for drying 1 kg of fresh <em>matooke</em> from 80 - 10% (wb) was 5,793 kJ.
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Luthra, Kaushik, Soraya Shafiekhani, Sammy S. Sadaka, and Griffiths G. Atungulu. "Determination of Moisture Sorption Isotherms of Rice and Husk Flour Composites." Applied Engineering in Agriculture 36, no. 6 (2020): 859–67. http://dx.doi.org/10.13031/aea.13822.
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HighlightsMoisture sorption isotherms of rice and husk flour composites were determined.Adsorption isotherms were best modeled by the Chung-Pfost and Oswin equations.Desorption isotherms were best modeled by the Polynomial and Chung-Pfost equations.The Modified Oswin model was the best for both adsorption and desorption.Abstract. Empirical models describing isotherms specifically for adsorption and desorption have not been described for rough rice and husk flour composites. Such models are vital for process control and monitoring operations which use rice husk and rice flours or their mixtures for food or material processing. The current study was undertaken to determine the moisture sorption isotherms of rice husk flour, rough rice flour and their mixtures subjected to different temperature levels. Effects of rice husk flour to rough rice flour ratio of 0:1 (0.0%), 1:49 (2.0%), 1:16 (5.9%), and 1:0 g/g (100.0%) on rough rice moisture isotherms at temperature levels of 20°C, 40°C, and 60°C were investigated. The dynamic dewpoint isotherm technique (DDI) was used to generate accurate isotherms. Several empirical models were tested to fit the experimental EMC data. All the isotherms showed typical sigmoidal type 2 shapes. The equilibrium moisture content (EMC) over equilibrium relative humidity (water activity) ranging from 10% to 95% showed temperature dependence. Hysteresis was evident for all samples, with a decreasing level at a higher temperature. Rice husk flour to rough rice flour ratio, as a factor, showed a significant effect on the EMC of rough rice. The EMC decreased with an increase in rice husk flour levels. Chung-Pfost and Oswin were the two best models for describing adsorption isotherm, and Polynomial and Chung-Pfost were the best models for fitting the desorption isotherm. Modified Oswin model was the best model amongst the two-variable models for describing both adsorption and desorption isotherms. Keywords: Empirical models, Equilibrium moisture content, Rice husk flour, Rough rice flour, Sorption isotherms.
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Kaymak-Ertekin, Figen, and Mustafa Sultanoğlu. "Moisture sorption isotherm characteristics of peppers." Journal of Food Engineering 47, no. 3 (2001): 225–31. http://dx.doi.org/10.1016/s0260-8774(00)00120-5.
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Ma, Chih-Ming, Hua-Wei Chen, and Gui-Bing Hong. "Moisture sorption isotherm characteristics ofHemerocallis FulvaandCymbopogon." Asia-Pacific Journal of Chemical Engineering 11, no. 5 (2016): 757–65. http://dx.doi.org/10.1002/apj.2007.
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Jakubczyk, Ewa, and Aleksandra Jaskulska. "The Effect of Freeze-Drying on the Properties of Polish Vegetable Soups." Applied Sciences 11, no. 2 (2021): 654. http://dx.doi.org/10.3390/app11020654.
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The aim of this study was to investigate selected physical and biochemical properties of four vegetable freeze-dried soups. The water content, water activity, pH, color parameters, antioxidant activity (EC50), total polyphenolic content of fresh tomato, pumpkin, beetroot, and cucumber, and freeze-dried soups were measured. Sensory analysis was applied to compare sensory attributes of fresh and rehydrated soups. The sorption isotherms of freeze-dried soups were obtained with the application of the static and dynamic vapor sorption (DVS) method. The application of the freeze-drying method enabled the obtaining of dry soups with a low water content of 2–3%. The drying caused a significant change of color of all soups. The redness of soups decreased after drying for the beetroot soups from +39.64 to +21.91. The lower chroma value of 25.98 and the highest total color change ΔE*ab = 36.74 were noted for freeze-dried beetroot soup. The antioxidation activity and total polyphenolic content were reduced after drying, especially for the cucumber and tomato soups. The Peleg model was selected to describe the sorption isotherms of dried soups. The sorption isotherm of freeze-dried cucumber and beetroot soups had a sigmoidal shape of type II. The shape of the moisture sorption isotherm for freeze-dried tomato and pumpkin soups corresponded more with type III isotherms. The DVS method can be used to characterize the moisture sorption isotherms of freeze-dried products.
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Jakubczyk, Ewa, and Aleksandra Jaskulska. "The Effect of Freeze-Drying on the Properties of Polish Vegetable Soups." Applied Sciences 11, no. 2 (2021): 654. http://dx.doi.org/10.3390/app11020654.
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The aim of this study was to investigate selected physical and biochemical properties of four vegetable freeze-dried soups. The water content, water activity, pH, color parameters, antioxidant activity (EC50), total polyphenolic content of fresh tomato, pumpkin, beetroot, and cucumber, and freeze-dried soups were measured. Sensory analysis was applied to compare sensory attributes of fresh and rehydrated soups. The sorption isotherms of freeze-dried soups were obtained with the application of the static and dynamic vapor sorption (DVS) method. The application of the freeze-drying method enabled the obtaining of dry soups with a low water content of 2–3%. The drying caused a significant change of color of all soups. The redness of soups decreased after drying for the beetroot soups from +39.64 to +21.91. The lower chroma value of 25.98 and the highest total color change ΔE*ab = 36.74 were noted for freeze-dried beetroot soup. The antioxidation activity and total polyphenolic content were reduced after drying, especially for the cucumber and tomato soups. The Peleg model was selected to describe the sorption isotherms of dried soups. The sorption isotherm of freeze-dried cucumber and beetroot soups had a sigmoidal shape of type II. The shape of the moisture sorption isotherm for freeze-dried tomato and pumpkin soups corresponded more with type III isotherms. The DVS method can be used to characterize the moisture sorption isotherms of freeze-dried products.
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Adil, S., J. Muhidong, and D. Yumeina. "Moisture sorption isotherm characteristics of sago flour." IOP Conference Series: Earth and Environmental Science 1230, no. 1 (2023): 012142. http://dx.doi.org/10.1088/1755-1315/1230/1/012142.
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Abstract The equilibrium moisture content of sago flour is essential information, especially for predicting the product’s shelf-life, which can be affected by various factors, such as temperature, relative humidity, and packaging condition. This research was conducted to study the characteristic of moisture sorption isotherm and determine the best mathematical equation model for studying sago flour’s isotherm sorption characteristics. Sago flour was stored in an incubator at a 10-80% humidity range with temperature variations of 30°C and 40°C. Humidity setting was done using various types of salt solutions. This study showed that all the sorption curves were found to be Type II. The higher the RH in the incubator, the higher the equilibrium moisture content of the material. Meanwhile, the water sorption capacity decreased with increasing temperature. Different models were fitted to the data, including Oswin, Chung-Pfost, and Halsey models. The Chung-Pfost model was found as the best model to represent the experimental data in the water activity range of 0.1-0.8.
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Rukmawati, Yulinda Eka Ayu, Sri Hartini, and Margaretha Novian Cahyanti. "Isoterm Sorpsi Air pada Tepung Ubi Jalar Terfermentasi dengan Angkak." Jurnal Kimia VALENSI 3, no. 1 (2017): 71–78. http://dx.doi.org/10.15408/jkv.v3i1.4814.
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The research was aimed to obtain moisture sorption curve , moisture sorption isotherm models and obtain determine the water content monoleyer of fermented sweet potato flour with red yeast rice.The moisture sorption isotherm model used are GAB (Guggenheim Anderson deBoer), BET (Brunauer Emmet Teller) and Caurie.Meanwhile, the test of modelling accuray by MRD (Mean Relative Deviation). The results showed that the water sorption isotherm curve of sweet potato flour fermented with red yeast rice Sigmoid shaped the approach of type II. The precise mathematical models are models of GAB (Guggenheim Anderson deBoer) with a value of MRD at a temperature of 30 °C, 35 °C, 40 °C respectively at 4.41%, to 2.50%, 3.37%. Moisture content of the monolayer at temperature of 30 °C, 35 °C and 40 °C in GAB model was 7.34%, 6.57%, 16.09%, BET model was 2.09%, 1.05%, 4.26%, and Caurie model was 1.41%, 1.36%, 1.42%.DOI: http://dx.doi.org/10.15408/jkv.v0i0.4814
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TAVAKOLIPOUR, H., and M. MOKHTARIAN. "APPLICATION OF NEURAL NETWORK FOR ESTIMATION OF PISTACHIO POWDER SORPTION ISOTHERMS." Latin American Applied Research - An international journal 44, no. 3 (2014): 189–94. http://dx.doi.org/10.52292/j.laar.2014.440.
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Moisture sorption isotherms for pistachio powder were determined by gravimetric method at temperatures of 15, 25, 35 and 40ºC. Some mathematical models were tested to measure the amount of fitness of experimental data. The mathematical analysis proved that Caurie model was the most appropriate one. As well, adsorptiondesorption moisture content of pistachio powder were predicted using artificial neural network (ANN) approach. The results showed that, MLP network was able to predict adsorption-desorption moisture content with R2 values of 0.998 and 0.992, respectively. Comparison of ANN results with classical sorption isotherm models revealed that ANN modeling had greater accuracy in predicting equilibrium moisture content of pistachio powder.
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Ramadhan, Wahyu, Joko Santoso, and Wini Trilaksani. "Moisture sorption isotherm and shelf-life estimation of freeze-dried surimi powder." BIO Web of Conferences 112 (2024): 09003. http://dx.doi.org/10.1051/bioconf/202411209003.
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Due to the fact that commercial wet surimi must be frozen, the adoption of dried surimi or surimi powder has emerged as the favored choice in the surimi industry to reduce costs. However, as surimi experiences the transition to its dried form, changes in moisture content can potentially influence quality and shelf life. To determine the optimal storage conditions for surimi powder, moisture sorption isotherms were evaluated over a range of water activity from 0.069 to 0.970. Five sorption models were then applied to the data. The water vapor permeability of three different packaging materials was also determined and the Labuza mathematical model was used to predict the shelf life of the product. This study attempted to assess the changes in the quality of surimi powder and predict its shelf life. The moisture sorption isotherm curve for dried surimi revealed a smooth sigmoid pattern, signifying equilibrium moisture content. The chosen sorption isotherm model, the Hasley formula (Me = log(log(ln(1/aw)) + 1.893) /-2.209), generated the mean relative determination value of 2.31. The Labuza model estimated the shelf life of dried surimi, revealing a predicted shelf life of 22.6, 4.5, and 6.1 months with retort pouch, HDPE, and OPP packaging, respectively.
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Alamri, M. S., A. A. Mohamed, S. Hussain, M. A. Ibraheem, and Akram A. Abdo Qasem. "Determination of Moisture Sorption Isotherm of Crosslinked Millet Flour and Oxirane Using GAB and BET." Journal of Chemistry 2018 (December 11, 2018): 1–8. http://dx.doi.org/10.1155/2018/2369762.
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Epoxy resin was prepared by crosslinking epoxidized oil and millet flour. The reaction was carried out at three different temperatures (25, 40, and 55°C) and zinc chloride levels (1, 2, and 3%). Moisture sorption isotherms were determined at 0.1 to 0.9 water activity (aw) using a gravimetric sorption analyzer (Q 2000). The sigmoidal shape (type II) of the resin isotherms exhibited lower equilibrium moisture content (EMC) at higher temperature. The experimental data were modeled using GAB (Guggenheim–Anderson–de Boer) and BET (Brunauer–Emmett–Teller). The EMC of the resin was significantly lower than that of the flour, which could be attributed to the decrease in the number of water-binding sites due to the creation of dense areas during crosslinking. The low root-mean-square error (RMSE) indicates that GAB and BET were suitable for predicting the water sorption isotherm for millet flour resin. The heat of sorption of the resin was large at low moisture content and increased at higher relative humidity. It is recommended that millet flour resin be used at relative humidity below 60%.
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Siripatrawan, U., and P. Jantawat. "Determination of Moisture Sorption Isotherms of Jasmine Rice Crackers Using BET and GAB Models." Food Science and Technology International 12, no. 6 (2006): 459–65. http://dx.doi.org/10.1177/1082013206072622.
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Moisture sorption isotherms of Thai Jasmine rice crackers were determined at 30, 45 and 60°C over a water activity range of 0.10 to 0.95 using a static gravimetric technique. Moisture sorption isotherms of rice crackers exhibited the sigmoid (Type II) shape. The moisture content of rice crackers decreased as temperature increased at a given water activity of the storage environment. The Brunauer, Emmett and Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models were applied to fit the experimental data. The isosteric heat of sorption at different moisture levels was also determined using the Clausius–Clapeyron thermodynamic equation. A nonlinear regression analysis method was determined to evaluate the parameters of sorption equations. The criteria used to evaluate the goodness of fit of each model were the mean relative percentage deviation modulus (E) and the percentage root mean square error (RMSE). The more extended range of application of the GAB equation over the BET equation was evident. The GAB model gave the best fit to the experimental sorption data for a wide range of water activity (0.10–0.95) while the BET model gave the best fit for a water activity range of less than 0.60. The GAB model is considered suitable to predict the moisture sorption isotherm of rice crackers since it gave low E and RMSE values. The heat of sorption values of rice crackers were found to be large at low moisture content and decreased with an increase in food moisture content.
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Kimani, Peter Kang’ethe, Ayub Njoroge Gitau, Duncan Onyango Mbuge, and Januarius Ondiek Agullo. "Modelling Moisture Sorption Isotherms of Superabsorbent Polymer Fabric for Desiccant Drying of Crops." Adsorption Science & Technology 2023 (August 24, 2023): 1–12. http://dx.doi.org/10.1155/2023/9992832.
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Desiccants are important in the drying of temperature-sensitive grains such as seeds for planting. Superabsorbent polymers (SAPs) have previously been identified for possible application in the drying of crops. Applying the gravimetric technique to measure the sorption isotherms and the effectiveness of the desiccant in crop drying was determined at temperatures 20, 25, 30, 35, 40, 45, 50, and 55°C. Using R statistical software, eleven sorption isotherm models were fitted to the experimental data using the nonlinear regression functions. The coefficients of each model were obtained. The modified Freundlich, modified Henderson, and modified Oswin models best predicted the experimental data for the study temperature range. Using symbolic regression and nonlinear regression in R software, four mathematical models were obtained. R software codes were assembled for the analysis of sorption isotherm models. Compared to the existing models, the developed models were found to give a more statistically accurate association between the temperature, moisture content of SAP fabric, and relative humidity.
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Prasad, S., K. K. Ahuja, and T. Hazra. "Moisture Sorption Isotherm (MSI) of Greek Yogurt." Journal of Scientific Research and Reports 31, no. 2 (2025): 330–40. https://doi.org/10.9734/jsrr/2025/v31i22854.
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In this study, Moisture sorption isotherm of Greek yogurt were investigated at 15°C, 25°C and 35°C using the standard, static gravimetric method. The purpose of this study was to understand the moisture behaviour of Greek yogurt and to evaluation models for prediction this behaviour. Experimental data were fitted to four models (GAB, BET, Halsey and Caurie) were tested for predicting the sorption data, the best fit as indicated by % RMSE, %RE and R2 values. The Moisture sorption isotherm (MSI) of Greek yogurt exhibited a sigmoid shape and was classified as Type II. The equilibrium moisture content increased gradually at the lower water activities followed by a steep rise at higher water activities. The BET monolayer decreased from 6.8 g of water /100g of solid at 15°C to 6.5 g of water /100g of solids at 35°C. The GAB monolayer decreased from 10.5 g of water /100g of solid at 15°C to 9.6 g of water /100g of solids at 25°C and further reduced to 9.1 g of water/100g of solids at 35°C. The bound water in Greek yogurt decreased from 13.92 % at 15°C to11.03% at 35°C. According to the study the GAB model emerged as the most effective in predicting the moisture sorption behavior of Greek yogurt.
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Obeng-Akrofi, George, Dirk E. Maier, Kurt A. Rosentrater, Thomas J. Brumm, and Joseph O. Akowuah. "EVALUATION OF MOISTURE SORPTION ISOTHERM FOR SHEA NUTS, VITELLARIA PARADOXA." Applied Engineering in Agriculture 41, no. 2 (2025): 169–78. https://doi.org/10.13031/aea.16087.
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HighlightsEquilibrium moisture content models were assessed for shea nuts.The Modified Halsey and Modified Oswin EMC/ERH models were found to be most appropriate in describing the sorption behavior of shea nuts.Critical moisture content for storage of shea nuts in the Sahel region was determined to be 5.08% to 6.68%.The study provided a basis for developing a calibration equation for a commercially available, hand-held, low-cost moisture meter for adoption in the shea nut value chain.Abstract. Shea nuts (Vitellaria paradoxa) are prone to mold deterioration during post-harvest handling, drying and storage. Evaluating the moisture sorption characteristics provides the basis to better understand their drying and storage behavior for prevailing climatic conditions during growing, harvesting and storage periods in shea-producing communities. Thus, this study sought to evaluate the moisture sorption isotherm of whole shea nuts across a temperature range of 20°C to 35°C, as is typical in the Sahel region. A series of goodness-of-fit indices were assessed to evaluate five moisture sorption models. The Modified Halsey and Modified Oswin EMC/ERH models were found to be most appropriate in describing the sorption behavior of shea nuts. The critical moisture content determined at 0.65-0.70 water activity across the 20°C to 35°C temperature range was 5.08% to 6.68%. Therefore, this study provided a recommendation for the safe storage moisture content of shea nuts and a basis for developing a calibration equation for a commercially available, hand-held, low-cost moisture meter to monitor effective drying, safe storage, and improved handling in the shea nuts value chain. Keywords: Keywords.,Equilibrium moisture content, Post-harvest handling, Safe storage moisture content, Shea nuts, Sorption isotherm.
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Mohamed, AA, MS Alamri, S. Hussain, MA Ibraheem, and Akram A. Abdo Qasem. "Moisture sorption isotherm of cross-linked wheat gluten and epoxydized oil using GAB and BET." Polymers and Polymer Composites 27, no. 9 (2019): 536–45. http://dx.doi.org/10.1177/0967391119853186.
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The moisture sorption isotherm of wheat gluten/epoxydized sesame or sunflower oil resin was determined at 25, 40, and 55°C. The resin was prepared by cross-linking epoxydized oil and wheat gluten using 1, 2, and 3% zinc chloride as the catalyst. The experiment was carried out over 0.1–0.9 water activity ( a w) range using gravimetric sorption analyzer (Q 2000, TA Instruments, New Castle, PA, USA). The resin isotherms were found to be type III shape where the equilibrium moisture content (EMC) was higher at lower temperatures. The EMC of gluten epoxy resin was dependent on the degree of cross-linking because more cross-linking decreased EMC. The Guggenheim Anderson-de Boer (GAB) parameters support the theory of the free volume as it relates to monolayer absorption. This could be attributed to the decrease in the number of water binding sites due to the development of dense areas during cross-linking and increase in the free volume. The GAB and Brunauer–Emmett–Teller were found to be suitable for predicting the water sorption isotherm for gluten protein resin because it provided low root mean square error. The heat of sorption based on the Clausius–Clapeyron equation (qst) increased with decrease in moisture content.
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Gao, Yulei, Zhu Li, Liyuan Zhao, and Jianxiong Lyu. "Effect of Heat Treatment on Hygroscopicity of Chinese Fir (Cunninghamia lanceolata [Lamb.] Hook.) Wood." Forests 15, no. 4 (2024): 630. http://dx.doi.org/10.3390/f15040630.
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Chinese fir (Cunninghamia lanceolata [Lamb.] Hook.) is a widely planted species of plantation forest in China, and heat treatment can improve its dimensional stability defects and improve its performance. The wood samples were heat-treated at various temperatures (160, 180, 200, and 220 °C) for 2 h. To clarify the effect of heat treatment on wood hygroscopicity, the equilibrium moisture content (EMC) was measured, the moisture adsorption and desorption rates were determined, the hygroscopic hysteresis was examined, and the Guggenheim, Anderson, and de Boer (GAB) model was fitted to the experimental data. The moisture absorption isotherms of all samples belonged to the Type II adsorption isotherm, but the shape of the desorption isotherm was more linear for heat-treated wood samples, especially when the heat treatment temperature was higher. According to the results analyzed with ANOVA, there were significant differences in equilibrium moisture content between the control samples and the heat-treated samples under the conditions of 30%, 60%, and 95% relative humidity (RH, p < 0.05), and the results of multiple comparisons were similar. The decrease in hygroscopicity was more pronounced in wood treated at higher temperatures. The EMC of the 160–220 °C heat-treated samples of the control samples was 14.00%, 22.37%, 28.95%, and 39.63% lower than that of the control sample at 95% RH. Under low RH conditions (30%), water is taken up mainly via monolayer sorption, and multilayer sorption gradually predominates over monolayer sorption with the increase in RH. The dynamic vapor sorption (DVS) analysis indicated that the heat-treated wood revealed an increase in isotherm hysteresis, which was due to the change in cell wall chemical components and microstructure caused by heat treatment. In addition, the effective specific surface area of wood samples decreased significantly after heat treatment, and the change trend was similar to that of equilibrium moisture content.
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Maigalura, K. A., and J. Suleiman. "MOISTURE SORPTION ISOTHERM CHARACTERISTICS OF AWARA FOOD." FUDMA JOURNAL OF SCIENCES 4, no. 2 (2020): 620–26. http://dx.doi.org/10.33003/fjs-2020-0402-247.
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Moisture sorption and storage stability of Awara were evaluated using gravimetric method. Guggenhein-Anderson-de boer (GAB) and Brunauer Emmett and Teller (BET) were used in evaluating sorption and desorption isotherm at temperature range of 30, 40 and 50oc in the range of water activity (0.1-0.9).Sigmoid moisture isotherm shapes were obtained at various temperatures. Lowest level EMC was obtained at highest temperature (500c).A non-linear regression analysis was used to fit both BET and GAB. GAB was found to generate higher coefficient of determination R2 (0.9986, 0.9959 and 0.9933) and lowest mean of relative percentage p% (0.231, 0.0061 and 0.0017) at temperature range (30, 40 and 500c) respectively. Safe % water and storage stability were all predicted from adsorption isotherm curve. 3.14, 3.19 and 3.10 were found to be the safe % water which corresponds to the 3.8aw for GAB adsorption graphs at 30, 40 and 500c temperatures respectively. This safe % water will be useful in packaging and determination of shelf- life of Awara.
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Willems, Wim. "A critical review of the multilayer sorption models and comparison with the sorption site occupancy (SSO) model for wood moisture sorption isotherm analysis." Holzforschung 69, no. 1 (2015): 67–75. http://dx.doi.org/10.1515/hf-2014-0069.
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Abstract The wood moisture sorption (WMS) isotherm is generally considered to contain information on the water-cell wall interaction and the abundance of water sorption sites (SSs) in wood. The Hailwood-Horrobin (HH) model – as an example of the multilayer surface sorption models – is discussed for its suitability to analyze experimental WMS isotherms, to elaborate the fundamental sorption parameters. Based on multiple independent experimental and theoretical arguments, it was concluded that the basics of the surface multilayer-sorption models do not apply to wood. This is clearly illustrated by applying the analysis to the temperature-dependence of WMS isotherms, to the comparison of adsorption vs. desorption isotherms and to the quantification of SSs in wood. A sorption site occupancy (SSO) model is presented as an alternative for the HH model. It provides a comprehensive, thermodynamically consistent and quantitative basis for the analysis of WMS isotherms. The predicted SS densities are realistic and can be used to quantify sorption hysteresis and cell wall relaxation.
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Alwan, Maha M. "Equilibrium Moisture Sorption Isotherms of Aspirin." Journal of Engineering 19, no. 4 (2023): 453–63. http://dx.doi.org/10.31026/j.eng.2013.04.03.
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Equilibrium Moisture sorption isotherms are very important in drying and storage analysis. Experimental moisture equilibrium data (adsorption and desorption) of Aspirin were determined using the static method of saturated salt solutions and that by exposing the material to different conditions of temperatures and water activities. Three different temperatures (25, 30, 40Cº) and water activities in the range of (6.3- 83.6%) were used. The results showed that the equilibrium moisture content increased with the increase in water activity at any temperature and decreased with temperature increase at constant water activity. The water activity increases with increasing in temperature when moisture content was kept constant. The sorption isotherm curves are of type II according to Brunauer`s classification. The hysteresis effect was not distinctly expressed only for equilibrium sorption values of Aspirin at 25ºC. The experimental results were fitted to two sorption models (GAB and Henderson).The average relative deviation between the experimental and calculated data were obtained to select the best model. The GAB and Henderson models, obtaining values of 3.54 and 1.42 % average relative deviation and coefficient of regression of 0.98 and 0.977 respectively. The Henderson model was found to be the best fit out of the two models to predict the sorption behavior of Aspirin.
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Mitrevski, Vangelce, Cvetanka Mitrevska, Vladimir Mijakovski, Ivan Pavkov, and Tale Geramitcioski. "Mathematical modelling of the sorption isotherms of quince." Thermal Science 21, no. 5 (2017): 1965–73. http://dx.doi.org/10.2298/tsci170118095m.
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The moisture adsorption isotherms of quince were determined at four temperatures 15, 30, 45, and 60?C over a range of water activity from 0.110 to 0.920 using the standard static gravimetric method. The experimental data were fitted with generated three parameter sorption isotherm models on Mitrevski et al., and the referent Anderson model known in the scientific and engineering literature as Guggenheim- Anderson-de Boer model. In order to find which models give the best results, large number of numerical experiments was performed. After that, several statistical criteria for estimation and selection of the best sorption isotherm model was used. The performed statistical analysis shows that the generated three parameter model M11 gave the best fit to the sorption data of quince than the referent three parameter Anderson model.
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Mitrevski, Vangelče, Cvetanka Mitrevska, Ljupčo Trajčevski, and Borče Mitrevski. "Review models of sorption isotherms." Journal on Processing and Energy in Agriculture 26, no. 1 (2022): 1–7. http://dx.doi.org/10.5937/jpea26-36839.
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Numerous mathematical models for approximation of sorption data of food and agriculture materials are available in the referent scientific and engineering literature. Depending on the number of parameters included in the model for approximation of moisture sorption data, the models may be one, two, three, four, five or more parametric. Also the sorption models may be included or not the temperature as a parameter into the equation. The objectives of the presented article was a review of one hundred seventy-two sorption no temperature dependent sorption isotherm models which used to for approximation equilibrium moisture data of food materials. For statistics evaluation of those models the equilibrium moisture data of quince were used. The value on coefficient of determination the root mean squared error, the mean relative deviation and graphical evaluation of the residual randomness were the main assessment criterions for statistical evaluation of the sorption isotherms model. Based on the performed statistical analysis it was concluded that the model of Popovski & Mitrevski i.e. M161 has the best statistical performances.
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CHUMA, Asako, Takenobu OGAWA, Takashi KOBAYASHI, and Shuji ADACHI. "Moisture Sorption Isotherm of Durum Wheat Flour." Food Science and Technology Research 18, no. 5 (2012): 617–22. http://dx.doi.org/10.3136/fstr.18.617.
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Prasad, Subhash. "Moisture sorption isotherm of Amrakhand (Mango shrikhand)." International Journal of Agriculture and Food Science 7, no. 6 (2025): 419–24. https://doi.org/10.33545/2664844x.2025.v7.i6f.483.
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Anyaiwe, Uche Capulet, Kennedy Ahamefula Okoronkwo, and Taiwo Ayodele Aderinola. "Moisture Sorption Characteristics of Lafun Flour." IPS Applied Journal of Nutrition, Food and Metabolism Science 2, no. 1 (2024): 11–18. http://dx.doi.org/10.54117/iajnfms.v2i1.60.
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Understanding the relationship between relative humidity and equilibrium moisture content (EMC) of any food material assist in maintaining good keeping quality. The adsorption isotherms for lafun supplemented with soy cord and residue were investigated. Six saturated salts were used which are Lithium chloride (RH: 11% aw, 0.22); potassium (RH: 93%, aw: 0.38); Magnesium chloride (RH: 33%, aw0.56); Potassium chloride (RH: 86%, aw: 0.40); Potassium acetate (RH: 23%, aw: 2.81); Potassium carbonate (RH: 43%, aw: 1.15) providing constant relative humidity environments ranging from 11 – 93%. The experimental data were compared with five widely recommended models in the literature for food adsorption isotherms (GAB, Oswin, Modified Oswin, BET and Henderson). The moisture adsorption isotherm were sigmoidal in shape and was influenced by temperature. Oswin model was best fits for all the samples at different temperatures. The monolayer moisture values for BET model of commercial ‘lafun’ sample are 0.040, 0.036 and 0.034 kgkg-1, ‘lafun’ enriched with curd 0.036, 0.038 and 0.031 kgkg-1, control ‘lafun’ 0.057, 0.038 and 0.025 kgkg-1, and ‘lafun’ enriched with residue 0.030, 0.036, 0.029 kgkg-1 at 10, 30 and 40ºC respectively while GAB model gave monolayer moisture values of 0.0682, 0.063 and 0.053 kgkg-1 for commercial ‘lafun’ sample, 0.045, 0.042 and 0.039 kgkg-1for ‘lafun’enriched with curd, 0.065, 0.042, 0.039 kgkg-1for ‘lafun’ commercial sample 0.081, 0.066 and 0.061 kgkg-1for ‘lafun’ enriched with residue at 10 ºC, 30ºC and 40 ºC respectively
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Karunanithy, C., K. Muthukumarappan, and A. Donepudi. "Moisture Sorption Characteristics of Corn Stover and Big Bluestem." Journal of Renewable Energy 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/939504.
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Moisture content is an important feedstock quality in converting it into energy through biochemical or thermochemical platforms. Knowledge of moisture sorption relationship is useful in drying and storage to preserve the quality of feedstocks. Moisture sorption isotherms for potential feedstocks such as corn stover and big bluestem are missing. EMC values of corn stover and big bluestem were determined using static gravimetric technique with saturated salt solutions (ERH 0.12–0.89) at different temperatures (20, 30, and 40°C). Depending upon the ERH values, EMC values were ranged from 8.0 to 19.6 and 8.8 to 19.2% db for corn stover and big bluestem, respectively, and they followed typical type II isotherm found in food materials. Nonlinear regression was used to fit five commonly used three-parameter isotherm models (i.e., modified Oswin model, modified Halsey model, modified Chung-Pfost model, modified Henderson model, and the modified Guggenheim-Anderson-de Boer (GAB) model) to the experimental data. Modified Halsey emerged as the best model with highF-statistic andR2values with lowEmandEsand fairly random scattered residual plot for corn stover and big bluestem. These models can be used to predict the equilibrium moisture content of these feedstocks starting from harvesting, drying, preprocessing, transportation, storage, and conversion.
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Fadimu, Gbemisola Jamiu, Monilola Kudirat Adeneken, Semiu Abolare Rasaq, et al. "Effect of drying methods on the sorption isotherms of plantain flour." Croatian journal of food science and technology 11, no. 2 (2019): 149–56. http://dx.doi.org/10.17508/cjfst.2019.11.2.01.
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The demand for plantain flour has increased in recent years due to its health benefits and industrial applications, however, there is dearth of information on the effect of drying methods on the sorption isotherm of plantain flour. In the present study, moisture sorption properties for unripe plantain flour using four drying methods at temperatures 27 °C, 37 °C and 42 °C were determined for water activity 0.10 to 0.80. The data generated were modelled using Peleg, GAB, Oswin, BET and Langmuir. The results revealed that the Equilibrium Moisture Contents decreased with an increase in temperature at all the water activities considered. Also, moisture isotherms of the plantain flour were not significantly (p&gt;0.05) affected by temperature. The coefficient of determination (R2) for the used models ranged from 0.640 and 0.986 and Peleg was the most appropriate for the adsorption isotherm of plantain flour out of all the models. The monolayer moisture content of the flour also showed that all the unripe plantain flours could be stored for longer periods at all the temperatures studied, as their Mo falls within acceptable range for storage
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Peter, I. . Akubor, and K. Egbekun Mathew. "Browning, Viscosity and Moisture Sorption Characteristics of Fresh and Stored African Breadfruit Kernel Flour." Chemistry Research Journal 2, no. 4 (2017): 139–45. https://doi.org/10.5281/zenodo.13954474.
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Flour was prepared from African breadfruit seeds and was stored in tin can and polyethylene bag at ambient temperature (30 °C) for 5 months. The browning index, viscosity and moisture sorption characteristics of the fresh and stored flour samples were evaluated. The equilibrium moisture content (EMC) slightly increased at low water activities but increased sharply at high water activities. The adsorption sorption isotherms of the fresh and stored samples were sigmoidal in shape (type 11 isotherm). The critical moisture content and surface area of ABKF were 5.4g H<sub>2</sub>O/100g and 1.8mg-1, respectively. At a constant shear rate, the viscosity was dependent on the ABKF concentration. Heated and Unheated flour dispersions exhibited shear thinning. The browning index of the floor increased while the viscosity decreased on storage. The moisture sorption characteristic of the flour in both packaging materials were not significantly (p>0.05) affected in storage. The tin can provided better keeping quality for the flour than polythene bag.
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Nazreen Elangko, Aqila Zulaikha, Junaidah Jai, Sherif Abdulbari Ali, and Norasmah Mohamed Manshor. "Moisture Sorption Isotherm of Cassava Starch Film Incorporated with Kaffir Lime Oil." ASM Science Journal 17 (July 7, 2022): 1–11. http://dx.doi.org/10.32802/asmscj.2022.1156.
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The use of bioplastic film has been gaining a lot of interest especially in food packaging, however knowledge on its stability during handling is limited. Moisture sorption isotherm is a study that determines the stability of the film when exposed to certain environmental conditions. The gravimetric method was used to determine the moisture sorption isotherm of cassava starch film incorporated with kaffir lime essential oil (EO) at 30°C and 40°C. The moisture content increases with increasing water activity for both 30°C and 40°C. The sorption data were fitted into 3 models and Oswin was found to be the best model to fit the data with R2 of 0.93 to 0.97. The sorption data were used to determine the net isosteric heat of sorption (qst) through the application of Clausius – Clapeyron equation which provides an approximation of the minimum energy required to remove water from a solid. Generally, the qst decreases exponentially with an increase in moisture content regardless of whether the film contains EO. The incorporation of EO within these temperatures does not affect the moisture content and heat of sorption of the starch-based bioplastic film, which shows its stability and potential as an additive in food packaging film.
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Jiang, Xiuping, Xiuping Jiang, Huanhuan Li, et al. "Moisture Sorption Isotherms and Isosteric Heats of Sorption of High-Pressure Treated Paulownia Wood under Different Storage Conditions." Transactions of the ASABE 62, no. 1 (2019): 105–14. http://dx.doi.org/10.13031/trans.12899.
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Abstract. Understanding of moisture sorption isotherms (MSI) is critical for predicting the stability of wood during handling, transport, and storage. The aim of this study was to evaluate the adsorption and desorption isotherm characteristics of high-pressure (HP) treated paulownia wood and to identify the best-fitting model to describe its sorption behavior. The equilibrium moisture contents (EMCs) of HP-treated paulownia wood were obtained using a static gravimetric method under different storage conditions: three temperatures (20°C, 30°C, and 40°C) and five water activity (aw) levels (0.32 to 0.95). Results showed that HP parameters did not significantly affect the MSI trend of treated groups. Eight modified models (modified Chung-Pfost, modified Henderson, modified Oswin, modified Halsey, Chen-Clayton, Guggenheim-Anderson-de Boer (GAB), simply modified GAB, and Peleg) were fitted to the experimental data. The Chen-Clayton model (temperature-dependent) produced randomized residuals and the best prediction performance for both adsorption and desorption among all models. Net isosteric heat of adsorption and desorption decreased from 7.55 to 4.84 kJ mol-1 and from 18.1 to 12.2 kJ mol-1, respectively, with an increase in EMC from 7.5% to 10%. The isosteric temperature (Tß) was 352 K for adsorption and 335 K for desorption, between which all the adsorption and desorption reactions proceeded at the same rate. All thermodynamic functions were adequately characterized by a power law model. Keywords: Equilibrium moisture content, High-pressure treatment, Modeling, Moisture sorption isotherm, Paulownia wood, Temperature, Thermodynamic analysis.
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Hawa, L. C., M. Efendi, U. Ubaidillah, and R. Yulianingsih. "Determination and modelling moisture sorption isotherms of dehydrated butterfly-pea (Clitoria ternatea L.) flower powder." IOP Conference Series: Earth and Environmental Science 924, no. 1 (2021): 012010. http://dx.doi.org/10.1088/1755-1315/924/1/012010.
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Abstract Butterfly-pea flower (Clitoria ternatea L.) is one of the edible flowers that is widely processed into dried flowers or powder form. Processed butterfly-pea flower is mostly used as a food colorant or flavonoid and anthocyanin-rich teas which are naturally present in the flower. Some polyphenolic acid, i.e., gallic acid, protocratic acid, and chlorogenic acid are also contained in this flower. During the storage period, color degradation occurs which will reduce the quality of the powder. Therefore, a study on the determination of moisture sorption isotherm from butterfly-pea powder is necessary information to maintain the quality of this product for a longer storage period. The objectives of this research are to evaluate the behavior of moisture sorption isotherm, construct its mathematical modelling and analyze the color changes at different temperatures and aw. 60 mesh of butterfly-pea powder with 28% initial moisture content (db) was stored at aw 0.3 – 0.9 (in a saturated salt solution containing MgCl2, K2CO3, NaC1, KC1, and BaCl2) at 30, 40, and 50°C by static gravimetric method. The results showed that based on the Brunauer classification, the behavior of moisture sorption isotherm of dehydrated butterfly-pea powder is in accordance with the Type II-sigmoid curve, while the Peleg model is the best model in predicting the moisture sorption isotherm. Recommended storage conditions for butterfly-pea flower powder are at 30°C with equilibrium moisture content at 23-30% (db). During storage powder color turns darker over the entire aw range with a color index of L* (lightness, 9.97); a* (redness, 2.33); b* (yellowness, -5.56).
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Al-Khalili, Maha, Nasser Al-Habsi, and Mohammad Shafiur Rahman. "Application of Dynamic Temperature-Humidity Chamber for Measuring Moisture Sorption Isotherms of Biomaterials as Compared to the Conventional Isopiestic Method." Adsorption Science & Technology 2021 (December 30, 2021): 1–13. http://dx.doi.org/10.1155/2021/1236427.
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Measurement of water activity and moisture sorption isotherms of foods and biomaterials are important to determine the state of water. In this work, a dynamic temperature-humidity (DTH) controlled chamber was used to measure water sorption isotherm and compared with the conventional isopiestic method. Temperature and relative humidity of DTH chamber can be controlled in the range of -15 to 100°C and 0 to 98%, respectively; thus, measurement of water activity at any point can be measured within the above ranges. The DTH chamber method showed high reproducibility as compared with the conventional isopiestic method when measured isotherms of cellulose, lignin, and hemicellulase were compared at 30°C. Finally, isotherm data of cellulose, lignin, and hemicellulase were generated in the temperature range of 10-90°C using DTH chamber, and these were modelled by BET and GAB equations. The model parameters were correlated with the temperature.
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Simonson, C. J., and R. W. Besant. "Heat and Moisture Transfer in Energy Wheels During Sorption, Condensation, and Frosting Conditions." Journal of Heat Transfer 120, no. 3 (1998): 699–708. http://dx.doi.org/10.1115/1.2824339.
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A numerical model for coupled heat and moisture transfer with sorption, condensation, and frosting in rotary energy exchangers is presented and validated with experimental data. The model is used to study condensation and frosting in energy wheels. Condensation/frosting increases with humidity and at some humidity level, water/frost will continually accumulate in the wheel. The sensitivity of condensation and frosting to wheel speed and desiccant type are studied. The energy wheel performance is also presented during both sorption and saturation conditions for a desicant coating with a Type I sorption isotherm (e.g., molecular sieve) and a linear sorption isotherm (e.g., silica gel). Simulation results show that the desiccant with a linear sorption curve is favorable for energy recovery because it has better performance characteristics and smaller amounts of condensation/frosting for extreme operating conditions.
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Botelho, Fernando M., Nilso J. Boschiroli Neto, Silvia de C. C. Botelho, Gabriel H. H. de Oliveira, and Michele R. Hauth. "Sorption isotherms of Brazil nuts." Revista Brasileira de Engenharia Agrícola e Ambiental 23, no. 10 (2019): 776–81. http://dx.doi.org/10.1590/1807-1929/agriambi.v23n10p776-781.
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ABSTRACT Knowledge of the water sorption phenomenon in Brazil nut seeds will allow proper handling of this product, especially with regard to adequate conditions for safe storage. Thus, the present study aimed to determine the sorption isotherms (desorption and adsorption) of Brazil nuts, fitting different mathematical models to the experimental data, as well as to examine the hysteresis effect. To obtain the sorption isotherms, the static method was employed at temperatures of 25, 35, 45 and 55 °C and air relative humidities varying from 10 to 80%. The psychrometric conditions of the air were acquired with the aid of acid solutions and specific saturated saline left inside desiccators with the samples. It was verified that for a given isotherm, the equilibrium moisture content of Brazil nuts increases with water activity increment. In addition, at a constant water activity, equilibrium moisture content decreases with temperature increase. The Copace, Henderson and Oswin are the models that best describe the hygroscopicity of the Brazil nut seed for both the adsorption and desorption processes. Hysteresis was more pronounced at lower temperatures and higher values of water activity. The moisture content value for storage at temperatures less than 55 °C, without the risk of fungal development, must be lower than 8.2% (d.b.).
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Adebayo, W. A., S. O. Andero, and R. O. Bankole. "The Sorption Isotherm of Pretreated Breadfruit Starch Flour." Journal of Food and Agriculture 17, no. 1 (2024): 1–14. http://dx.doi.org/10.4038/jfa.v17i1.5315.
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This study investigated the sorption isotherm of breadfruit starch with the view of providing sorption isotherm data that will enhance its storability and utilization in food formulation. The sorption isotherm of breadfruit starch flour at temperature levels (30, 35, 40, and 45 ℃) and water activity (ranging from 0.1 – 0.9) using sulphuric acid was experimentally investigated in an incubator until equilibrium moisture content (EMC) was obtained gravimetrically. The sorption data obtained was fitted into six different existing mathematical models using linear (Origin statistical procedure) and non-linear (Gauss-Newton) regression programs. The models were compared using the coefficient of determination (R2), residual mean square error (RMSE) and the sum of square error (SSE). The sorption models' predictive parameters were used to determine the best-fitting model. The results showed that the Modified Henderson model and Halsey model are best suited to predict the sorption isotherm of breadfruit (Artocarpus altilis) flour. In conclusion, this research gives insights for understanding the sorption isotherm behaviour of the breadfruit flour which is crucial in predicting shelf-life stability, designing and optimization of drying equipment and choosing appropriate packaging material for the product.
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Tantala, Juthamas, Chitsiri Rachtanapun, Wirongrong Tongdeesoontorn, Kittisak Jantanasakulwong, and Pornchai Rachtanapun. "Moisture Sorption Isotherms and Prediction Models of Carboxymethyl Chitosan Films from Different Sources with Various Plasticizers." Advances in Materials Science and Engineering 2019 (January 8, 2019): 1–18. http://dx.doi.org/10.1155/2019/4082439.
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Carboxymethyl chitosan (CMCH) from different chitosan sources (shrimp, crab, and squid) and molecular sizes (polymer and oligomer) were synthesized via carboxymethylation reaction. The CMCH films were prepared by solution casting. All the CMCH films had high water solubility, higher than 85% of the dry matter of the films. The sorption isotherm of the CMCH films was evaluated at several values of relative humidity (0% RH, 23% RH, 34% RH, 43% RH, 65% RH, 77% RH, and 86% RH) at 25 ± 1°C. The equilibrium moisture content values of all the CMCH films were low at lower aw but increased considerably above aw = 0.65. The sigmoidal moisture sorption isotherms of this product can be classified as type II. Understanding of sorption isotherms is an important prerequisite for the prediction of moisture sorption properties of films via moisture sorption empirical models. The experimental data were analyzed and fitted by the nine sorption models. The various constants determined by linear fitting of the sorption equation with r2 values were in the range of 0.7647 to 0.999. The GAB model was found to be the best-fitted model for CMCH films (aw = 0.23–0.86, 25 ± 1°C), and the model presented the optimal root-mean-square percentage error (%RMS) values when compared with other models. In conclusion, it can be stated that the GAB model was found to be better estimated for predicting the CMCH films than other models. Therefore, the constant derived from different sorption models were applied for use in terms of information and for the determination of the stability of CMCH packaging films for specific end uses.
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Kurniawan, Y. R., Y. A. Purwanto, N. Purwanti, and S. Budijanto. "Measurement of Moisture Sorption Isotherm by DVS Hydrosorb." IOP Conference Series: Earth and Environmental Science 147 (May 2018): 012017. http://dx.doi.org/10.1088/1755-1315/147/1/012017.
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