Mathematical modelling of the sorption isotherms of quince

Abstract

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.

Experimental Measurement of Moisture Sorption Isotherms and Isosteric Heat of Palm Hearts (Jomare) Harvested in the Algerian Sahara

“…Sorption isotherms are essential parameters for drying and cannot be predicted by theory but must be experimentally established. The sorption isotherm curves give information on the distribution and binding intensity of water molecules [9] as well as their functional availability in biochemical and biological substances. they also provide reliable data on the fluid balance of the product to know its stability range after drying, the sorption isotherms curves provide information to ensure better preservation during storage.…”

Statistical evaluation of two-parameter sorption isotherm models

“…The equilibrium moisture content values (X eq ) of quince slices (Table 1), obtained at different water activity values (a w ) and four different temperatures (Mitrevski et al, 2018), were fitted with sixty two-parameter sorption isotherm models M01-M60 (Table 2). In the scientific literature, the following statistical critera are used for the goodness of fit of a sorption isotherm model, i.e.…”

“…Quince samples for the determination of sorption isotherms were predried to the final moisture content in a convective dryer at an air drying temperature of 60 o C and an air drying velocity of 1 m/s for a period of 7 hours.The equilibrium moisture contents of the quince samples were determined at temperatures of 15, 30, 45 and 60 o C, using the static gravimetric method (Mitrevski et al, 2018). Ten saturated salt solutions L i Cl, CH 3 COOK, MgCl, K 2 CO 3 , Mg(NO 3 ) 2 , NaBr, SrCl 2 , NaCl, KCl and BaCl 2 were utilized to obtain the constant equilibrium relative humidity in the glass jars ranging from 0.110 to 0.920.…”

“…The glass sorption jars were placed and kept in the temperature controlled SANYO MCO-15AC cabinet (SANYO Electric Co., Ltd. Refrigeration Products Division 1-1-1, Sakata Oizumi-Machi, Ora-Gun, Gunma 370-0596 Japan), and maintained at temperatures of 15, 30, 45 and 60 o C (with an accuracy of ± 0.1 o C). Three replications were made at each temperature and equilibrium relative humidity in the glass jars, using two samples per replication, and the average values of the equilibrium moisture content were calculated (Mitrevski et al, 2018). Changes in the sample masses were recorded every 7 days using the electrical balance KERN PLJ360-3M with a precision of 0.001 g (Kern&Sohn GmbH, Ziegelei 1, 72336 Balingen, Germany).…”

“…With regard to food materials, sorption isotherms are of great importance to modelling the drying process, designing and optimising the drying equipment, predicting the shelf-life stability, calculating changes in the moisture content during storage, and selecting the appropriate packaging material (Gal, 1987). Over the last two decades, an increasing number of studies have been reported in the scientific and engineering literature addressing the following issues: methods for determining sorption or desorption isotherms (Mitrevski et al, 2015;Mitrevski et al, 2018), temperature dependence between sorption isotherms (Popovski&Mitrevski, 2004), determination of sorption heat (Kaymak- Ertekin and Gedik, 2004), and mathematical models for approximating the moisture sorption of food materials (Mitrevski et al, 2012;Mitrevski et al, 2015a). Depending on the number of parameters included, models for approximating the moisture sorption data of materials are referred to as one-parameter, two-parameter, three-parameter, or multi-parameter models.…”