Modelling of the sorption isotherms and determination of the isosteric heat of split pistachios, pistachio kernels and shells

Abstract

Soleimanifard S., Hamdami N. (2018): Modelling of the sorption isotherms and determination of the isosteric heat of split pistachios, pistachio kernels and shells. Czech J. Food Sci., 36: 268-275.We aimed to measure the equilibrium moisture content of the Ohadi variety of pistachio shells, pistachio kernels and split pistachios using gravimetric methods at 25, 40, 55, and 70°C and saturated salt solutions with water activities ranging from 0.08 to 0.97. Then, 11 mathematical models were used to select the best model for data description. The GAB model, which had the maximum value for the correlation coefficient (R 2 ) and minimum values for the chisquared test (χ 2 ) and root mean square error (RMSE), was identified as the best model for split pistachios and pistachio kernels. The Caurie model, meanwhile, was identified as the best model for pistachio shells. In this test, there was no significant hysteresis between the desorption and adsorption curves. Furthermore, the isosteric heat of adsorption and desorption were also determined using thermodynamic equations (e.g., the Clausius-Clapeyron equation).

Assessment of moisture adsorption and desorption isotherms, hysteresis phenomenon and thermodynamic analysis of habanero chili (Capsicum chinense) powder

“…Similar trends were found by Kaymak-Ertekin and Gedik (2004), who calculated the net isosteric heat of adsorption and desorption of grapes, apricots, apples, and potatoes. Soleimanifard and Hamdami (2018) observed a similar trend in split pistachios, pistachio kernels, and shells. The relationship between total isosteric heat of sorption (Q st ) and EMC is shown in Figure 4B.…”

“…On the other hand, dehydrated foods offer more advantages over fresh ones since moisture is decreased by evaporation, and thus, their stability is increased. Water plays an important role in the conservation and preservation of food systems; therefore, it is important to generate information about the behavior of free or bound water that constitutes the a w (Pavon-Garcia et al, 2015;Soleimanifard and Hamdami, 2018;Guillen-Velazquez et al, 2023).…”

Experimental and Modeling Investigations on the Water Sorption Behaviors of Autoclaved Aerated Concrete

“…These models were selected in their own field after conducting preliminary analyses to assess their suitability. Their validity was demonstrated in other fields, mainly for modeling food sorption isotherms [ 35 , 36 , 37 ]. These were the models proposed by Peleg [ 38 ], Redlich-Peterson [ 20 ], and Caurie [ 39 ], by the following equations:…”

Moisture sorption isotherms characteristics for shelf‐life prediction of peanuts (Arachis Hypogaea L.)

“…This relationship between a w and EMC is described by sorption isotherms. The information obtained from sorption isotherms is quite helpful in predicting shelf life, package design, mixing of foods and establishing drying models 5 …”

“…The information obtained from sorption isotherms is quite helpful in predicting shelf life, package design, mixing of foods and establishing drying models. 5 Peanut is a leguminous crop with a high protein (26%) and oil content (44-56%). 6 In India, peanuts are grown in four seasons: rabi, kharif, spring and summer.…”