Integrated grading and solar drying of meat: second progress report

Abstract

Beef strips of approximately 20 mm. thicknesses were prepared and pre-treated in three different ways prior to solar drying in a cabinet and tunnel types solar dryers over a period of three drying cycles. Weather data monitored during the drying period indicated poor drying conditions prevailing during this period of the experiment (early August). As a direct consequence of this, dried meat samples stored for only a period of four days under ambient conditions became heavily contaminated with spoilage microflora, and moisture content and water activity (Aw) values were also too high to afford shelf stability under ambient storage. Under the same ambient conditions the tunnel solar dryer had by far better drying conditions within its drying chamber than that of the cabinet solar dryer, due to its ability to generate sufficient heat for drying purposes and the presence propels the heat generated towards the insulated drying chamber. However, the overall performance of the solar dryers was directly related to the prevailing ambient conditions during the experiment, in the terms of relative humidity and temperature of the air and the air flow rate. The spice mix used for meat pre-treatment was surprisingly devoid or microflora to any significant extent, indication the presence of some inherent antimicrobial factors, bit his condition was no manifested in the dried meat products' due to the prevailing poor ambient conditions and high moisture content and water activity values obtained for the dried meat products