Selection of a the best suitable thin-layer drying mathematical model for vacuum dried red chili pepper

Abstract

Red Chili pepper (Capsicum frutescens L.) with 50 (±0.02) g weight and 6.12 ± (0.02) humidity on dry basis were dried in vacuum oven using combined 2 different temperature (50 - 75°C) and 3 different pressure (0.05, 7 and 13 kPa) until the humidity fell down to 0.16 ± (0.01) on dry basis. Vacuum drying processes were completed between 3 and 19.17 h. In this study, measured values were compared with predicted values obtained from twenty one thin layer drying theoretical/semi-empirical/empirical equations. Models whose coefficient of correlation (R2 ) values are highest were chosen to be the best models. According to this, the best models of combined 50°C temperature with vacuum levels (0.05, 7 and 13 kPa) was found to be “Modified Henderson & Pabis” Model, combined 75°C temperature with vacuum levels (0.05, 7 and 13 kPa) was found to be “Alibas” Model.