Solar Pre-drying Study of Sorption Isotherms of Saharan Fish

Abstract

AbstractThe objective of this study is to determine the desorption isotherms of Saharan fish in order to predict the ideal conditions for solar drying and storage. The experiments were conducted at different temperatures using the gravimetric-static method, with a defined range of water activity. The results reveal that the desorption isotherms of Saharan fish behave in accordance with type II, as per the BET classification. Specifically, the equilibrium moisture content decreases with increasing temperature for each level of water activity, and a clear hysteresis effect is observed. Four mathematical models were applied to fit the experimental data, and it was found that the GAB model accurately represents the desorption isotherms of Saharan fish. Important parameters such as the isosteric heat of sorption and the shelf life of the product were deduced from these isotherms. The physicochemical analysis of our Saharan fish provides detailed information on their composition and properties, while the microbiological analysis of fresh and dried fish reveals the presence of various microorganisms, with varying microbial load. These results offer vital information for the industry, thereby contributing to the improvement of quality management, shelf life, and production of Saharan fish products.