title: Effect of far-infrared radiation assisted microwave-vacuum drying on drying characteristics and quality of red chilli.
abstract: Fresh red chilli (Capsicum frutescens L.) was dried using microwave-vacuum drying (MVD) and the far-infrared radiation assisted microwave-vacuum drying (FIR-MVD) method. The MVD was operated using the microwave power of 100, 200 and 300 W under absolute pressure of 21.33, 28.00 and 34.66 kPa. In terms of FIR-MVD, far-infrared power was applied at 100, 200 and 300 W. The effect of drying conditions, i.e., microwave power, absolute pressure and FIR power, on drying characteristics and qualities of dried product were investigated. It was observed that an increase in microwave power and FIR power with a decrease in absolute pressure could accelerate the drying rate. It was also found that FIR-MVD method required shorter drying time than MVD. Moreover, qualities, i.e., color changes, texture, rehydration ability and shrinkage, of FIR-MVD chilli were found to be better than those of MVD. Consequently, the optimum drying condition of FIR-MVD within this study was microwave power of 300 W under absolute pressure of 21.33 kPa with FIR power of 300 W.
authors.affiliation: Department of Food Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, 10140 Thailand.
authors.forename: Rattapon
authors.initials: R
authors.lastname: Saengrayap
authors.affiliation: Department of Food Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, 10140 Thailand.
authors.forename: Ampawan
authors.initials: A
authors.lastname: Tansakul
authors.affiliation: School of Engineering, University of Guelph, Guelph, Ontario N1G 2W1 Canada.
authors.forename: Gauri S
authors.initials: GS
authors.lastname: Mittal
keywords: Chilli; Drying; Far-infrared; Microwave-vacuum drying; Quality