Maximizing the Benefit of Orange Pomace Matouk

A study was carried out to maximize the benefits of orange pomace through different treatments including chopping process at different times (5, 10 and 15 s), pressing using a laboratory scale hydraulic press unit at four different levels of applied pressure (50, 100, 150 and 200 bar) for exposure times of (5, 10, 15 and 20 min) with pre-treatment of the samples using Ca(OH)2 in comparison with non-treated samples. Following this process, the most proper pressing treatment was assigned for a drying process using a conduction rotary heating unit at heating surface temperatures of (100, 110, 120, 130 and 140 C) for drying times of (10, 20, 25, 30, 35 and 40 min). Two different drying models (Lewis model and Henderson & Pabis's model) were assigned for describing the drying data and predicting the change in orange pomace moisture content. Quality evaluation tests were also conducted for the dried samples including chemical composition, water retention capacity (WRC) and oil holding capacity (OHC). The results show that chopping process for 10s showed the highest extraction efficiency, the samples treated with Ca(OH)2 and pressed at 150 bar for 15 min recorded the lowest value of moisture content (105.46% d.b.). Meanwhile, the drying process at heating surface temperature of 110 C for 40 min showed the lowest reduction in pomace quality. Also, Lewis model could describe the drying behavior of orange pomace satisfactory.