Microwave-Assisted Foam Mat Drying of Kumquat Puree and Investigation of Some Parameters

Abstract

Kumquat puree, with the initial moisture content of 81.02 ± 0.8 (w.b) on wet basis, were dried using two different methods, microwave, and fan assisted hot air microwave (FAHA) until moisture content of kumquat was reduced to average of 25.02 ± 1.35 w.b. Microwave trials at 1.8 , 3.6, and 5.4 Wg- 1 lasted for 51, 19 and 12 min, respectively. FAHA trials at 1.8 , 3.6, and 5.4 Wg-1 at 100 ˚C and 1.8 , 3.6, and 5.4 Wg-1 at 150 ˚C lasted for 46, 38, 18, 15, 12 and 11 minutes, respectively. For foam drying, Soy protein (1%) and Maltodextrin (1%) were used as foaming agent, and carboxymethyl cellulose (1%) was used as foam stabilizer. After the drying trials, dried kumquat was powdered. The scope of this study, a comparison of measurements of moisture with that of the predicted results was made, obtained from 13 thin layer drying models. Further, drying rate, color parameter and energy consumptions were compared for each trial. For all microwave and FAHA trials, Kulcu et. al. (Unpublished) model was the most appropriate models depending on lowest chi-square value and root mean square error values. Color and specific energy consumptions (SEC) were categorized by using (SPSS) and chosen the best efficiency condition for drying as considering SEC. The most suitable drying process according to SEC was obtained at 5.4 Wg-1 microwave drying method with value of 1.94 Whg-1.