Drying kinetics of porang ( Amorphophallus mueller B.) chips under open sun drying

Abstract

The drying behavior of porang (Amorphophallus muelleri Blume) chips under open sun drying has been conducted. The aim of present study was to determine the drying kinetics and mathematical modeling of the chips and color alteration during open sun drying. The drying process was carried out for 21 hours at the open space with direct sunlight with 3, 5, and 7 mm of chips thickness variation. The average initial water content of the chips was 89.34±1.24 %wb (wet basis), and 7.77±0.44; 9.61±1.31; and 12.88±1.47% wb (wet basis) of final moisture content at the end of process for 3, 5, 7 mm of chips thickness, respectively. The nonlinear analysis for subjected model indicated that the Midilli et al model was satisfactorily describe the drying curve of the chips with following constants, i.e. a = 0.9894; k = 0.0129; n = 2.8962; b = 0.0064. During drying, browning occurs on porang chips with decreased brightness index (L∗) and yellowness index (b∗) and increased redness index (a∗).