Desorption isotherms and isosteric heat of anaerobic fermentation residues

In this work the sorption behavior of Terfezia boudieri truffle was studied and evaluated using the static gravimetric method. This approach permits the measurement of the sorption isotherms at three given temperatures 30, 40, and 50°C. Where in the first step experimental sorption data was collected, and then was used in order to identify the thermodynamic properties of truffle. Several results were found by conducting this study. First, the optimal water activity (aw) for conserving T. boudieri truffles was determined and found to be in range of the values 0.24 and 0.31 as a function of temperature. Additionally, net isosteric heat and entropy of sorption, which are two parameters studied during this study, were found to be decreasing when the water content increased; where the existence of the compensation theory of enthalpy–entropy for Terfezia boudieri was confirmed. Second, net isosteric heat and entropy of sorption, which are two parameters studied during this study, were found to be decreasing when the water content increased; where the existence of the compensation theory of enthalpy–entropy for Terfezia boudieri was confirmed. Finally, the isokinetic temperatures were 338.69 and 324.35 K for desorption and adsorption, respectively. As well as the free Gibbs energy was found to be positive for sorption which indicates that the sorption process as a non‐spontaneous one. Moreover, the spreading pressure varied in a range of 0.03–0.25 J/m2, while the aw increased. This study is a contribution to the drying, packaging, and conservation of white truffle. Practical applications White truffle has been widely used in many food products related applications, and pharmaceutic industry. White truffle is only available in certain seasons; consequently its storage process for long periods is a necessity in order to ensure the supply chain over the year. Furthermore, this particular food product needs a very specific storage conditions which may affect its quality and shelf‐life. This work aimed to determine and evaluate the water sorption properties in an adequate range of temperature and relative humidity. The mathematical models and the thermodynamic analysis conducted throughout this study, in addition to the reported data are useful to find the optimal and adequate storage conditions to preserve the quality and prolong the white truffle shelf‐life.

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“…Isosteric heat of sorption (

Q_{isos}

) is defined as a parameter that designates the state of absorbed water molecules by the solid matrix. Moreover, this parameter (

q_{isos}

) indicates the quantity of energy above the energy of water vaporization (

L_{vap}

) that is required for the sorption process (Garcia‐Perez, Carcel, Clemente, & Mulet, 2008; Poós & Szabó, 2019).

q_{isos} = Q_{isos} - L_{vap}

Using the Clausius–Clapeyron equation (Tsami, 1991), net isosteric heat of sorption is calculated through the experimental sorption curves.…”

Section: Methodsmentioning

confidence: 99%

Exploring the sorption and thermodynamic proprieties of white truffle (Terfezia boudieri)

Tagnamas

Bahammou

Moussaoui

et al. 2021

J Food Process Engineering

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Metagenomic characterization of anaerobic fermentation in weathered coal for biomethane production enhanced by landfill leachate

Song,

Guo,

Deng

et al. 2024

Process Safety and Environmental Protection

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Moisture Sorption Isotherm and Isosteric Heat of Butterfly-pea Flowers (Clitoria ternatea)

Hawa

Efendi

Ubaidillah

et al. 2021

IOP Conf. Ser.: Earth Environ. Sci.

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Butterfly-pea (Clitoria ternatea) flowers are containing various active compounds such as flavonoids, myricetin, quercetin, flavonols, and anthocyanins which have potential as antioxidants. Dried butterfly-pea flower is often used as an ingredient of herbal tea drinks. The drying procedure for the butterfly-pea flower is important to maintain the shelf-life. However, during the drying process, anthocyanins are easily be degraded before reaching the balance of water content. Therefore, a study focus on moisture sorption isotherm of fresh butterfly-pea flowers is needed. This present study aims to determine the balance of water content and isosteric heat of butterfly-pea flowers using a static gravimetric method. Water activities were conditioned using chemical solutions of KOH, MgCl2, K2CO3, NaCl, KCl, and BaCl2 with a water activity range of 0.06-0.90. The hysteresis curve was determined using desorption and adsorption samples with various temperature variations of 30, 40, and 50°C. The isothermal behavior of butterfly-pea flowers was determined based on GAB, BET, Halsey, Oswin, and Peleg models. As a result, the Peleg model was found to be the most suitable model to represent the moisture sorption isotherm of butterfly-pea flowers and based on Brunauer classification including the Type II-sigmoid curve in which has been statistically analyzed using determination coefficient (R 2), mean relative modulus (P), and root mean square error (RMSE). The hysteresis curve indicated that the balance of water content of the desorption sample is higher than the adsorption sample on the same water activity level. The net isosteric heat in the desorption and adsorption samples were 48.529 exp (−xe/0.0734) and 53.591 exp (−xe/−0 0797), respectively.

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Desorption isotherms and isosteric heat of anaerobic fermentation residues

Cited by 3 publications

References 39 publications

Exploring the sorption and thermodynamic proprieties of white truffle (Terfezia boudieri)

Exploring the sorption and thermodynamic proprieties of white truffle (Terfezia boudieri)

Metagenomic characterization of anaerobic fermentation in weathered coal for biomethane production enhanced by landfill leachate

Moisture Sorption Isotherm and Isosteric Heat of Butterfly-pea Flowers (Clitoria ternatea)

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