Effect of Solar Collector Geometry on Drying Time and Nutritional Properties of Levant Quality Hazelnuts

OpenAlex · English

This study examines the impact of drying Levant quality hazelnut samples, including husk and shell, using hot air heated by solar panels at a constant speed of 6 m/s. The study also investigates the impact of collector irradiation absorption surface geometries on hazelnut drying time. A solar collector with four types of air duct geometry was used to dry hazelnuts. The radiation-absorbing surface of the air duct was manufactured flat, and three different trapezoidal geometries (30, 45 and 60 angles) were used. The mass losses of hazelnuts were measured and determined at regular intervals. In addition, the total phenolic content, the DPPH radical scavenging activity, the FRAP, the free fatty acid content, the peroxide value and the moisture content were measured. For the purpose of comparison, some of the products have been dried by means of unheated air at ambient temperature. The pre-drying process (withering process) to separate the hazelnuts from husk, only took 1.5 days (14 h excluding night). In these systems, the shelled fresh hazelnuts, separated from the husk, fell below the equilibrium moisture content of 6% in 2 days (except for 18 h at night). It was found that the most suitable collector geometry for all the parameters studied in the drying of hazelnuts with solar collectors was 45 degrees, and that other geometries could be used in terms of food properties.