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Local fish markets are often saturated during periods of full production. Solar drying offers a suitable alternative to reduce losses of surpluses, and to preserve products for a longer period. In this respect, this work was carried out to study the effect of the air indirect solar convective drying process on the dehydration kinetics of anchovy. Experimental drying kinetics was measured at four air temperatures (50, 60, 70 and 80 °C) and for a constant air flow of 300 m3/h. The moisture desorption isotherms of the anchovy were determined at three temperatures (30, 40 and 50 °C), using the static gravimetric method to determine the optimum water activity for conservation of the nets anchovy. Experimental results showed that the drying kinetics of the anchovy was accelerated synchronously with the increase of the air temperature. The value of optimal water activity for conservation of anchovy is aw = 0.30 and the desorption isotherms suggest a non spontaneous process. Nine drying models were adapted to the drying data; the Logarithmic model allowed better adaptation than the other models. The effective diffusion coefficient value Deff determined by Fick’s second law varied from 3.84 10−9 to 5.60 10−9 m2/s and the activation energy value was Ea = 12.90 kJ/mol.

Urtica urens is one of the main medicinal plants used in the pharmaceutical industry and traditional medicine. It is necessary to know the process of drying and storage of this product. This work is a contribution to the understanding of the mass transfer mechanisms by modeling the drying process of the Urtica urens leaves. The isothermal diffusive model is based on solving the one-dimensional Fick equation. Moreover, an algorithm of minimization compiled by MATLAB is used in this study to get the optimal parameters of the model. The results showed a reasonably good agreement between the values predicted from the model and the experimental observations. This confrontation has helped to identify the diffusion coefficient and the activation energy of the Urtica urens leaves. The effective diffusivity values changed from 4.94 10-11 to 9.66 10-11 within the given temperature range, and the activation energy was found to be 29.34 . In fact, the proposed model accurately describes, on a macroscopic scale, mass transfer processes in the product., Arabian Journal of Medicinal and Aromatic Plants, Vol 6, No 1 (2020)

Durum Wheat is deemed as one of the most important agricultural elements in the food system. Gamma irradiation treatment proves to be an efficient technique to decontaminate cereals so that we can ensure their hygienic quality during conservation. This paper seeks to study the hygroscopic behavior of irradiated and non-irradiated durum wheat at three temperatures 30 °C, 40 °C and 50 °C using the static gravimetric method. Furthermore, modeling the relationship between water activity and the equilibrium moisture content has been conducted through several models. GAB and Halsey were selected as convenient models that represent moisture sorption isotherms data for durum wheat. The net isosteric heat of sorption, the specific surface area of sorption was calculated via several equations including the Marquardt–Levenberg algorithm. As a result, the study of the samples reveals that the ionization at a low dose affects the moisture sorption of durum wheat, Moroccan Journal of Chemistry, Vol 8, No 4 (2020): in progress will be publishing

Medicinal plants are photosynthetic organisms that have potential biological activities thanks to their phytochemical compounds. However, the potential of these activities inhabits due to several factors such as temperature and humidity. This paper presents the results of several experimental studies on moisture adsorption phenomena using experimental design methodology and the gravimetric static method as keys to study the impact of temperature and humidity on the powder of the Taraxacum Officinale leaves as well as modeling the moisture adsorption at different temperatures. Additionally, empirical models are fitted in order to regress the isotherms data and represent the relationship between the equilibrium moisture content of the product and water activity. The analysis of the interaction between these factors is based on experiments, statistical calculations, and the analysis of variance method which allow to verify the fact that the humidity affects the powder stability more than the temperature or their interactions, Moroccan Journal of Chemistry, Vol. 8, No 1 (2020)