EMPIRICAL MODELING OF MICROWAVE FINISH DRIED INDIAN GOOSEBERRIES (PHYLLANTHUS EMBLICA) Aruna Singh 1 , Aswin Venugopal 1 and Mahesh Ganesapillai * 1, 2 1 Mass Transfer Laboratory, Chemical Engineering Division, School of Mechanical and Building Sciences, VIT University, Vellore-632014, Tamilnadu, India. 2 Department of Chemical Engineering, Faculty of Engineering, Un.Box 455, P.C. 54124, University campus, Aristotle University of Thessaloniki, 54006 Thessaloniki, Greece. *Corresponding author: drmaheshgpillai@gmail.com ; maheshgpillai@vit.ac.in Abstract Fresh Indian Gooseberries (Phyllanthus emblica) with an initial moisture content of 90- 95 % (db), were sliced and then exposed for dehydration using three different drying regimes viz. convection (40°C, 50°C and 60°C at 1.45 m/s); microwave (100, 180 and 300 W power) and microwave assisted convective drying (at 40°C / 100 W). Drying was continued until the berries moisture fell down to 14 % (db). The microwave drying characteristics, effective moisture diffusivity were determined with respect to sample thickness, microwave output power and sample load revealed higher power (300 W), lesser thickness (0.001 m) and load (25 g), increased drying rates and reduced drying time. Microwave finish drying reduced the convection drying time by about 64.3%. In this study, measured values were compared with predicted values obtained from different semi-empirical equations. The sample thickness strongly affected the moisture diffusivity where the lower sample thickness provided higher values of effective diffusivity of 9.17×10 −11 and 11.6×10 −11 m 2 s −1 for samples. In spite of higher initial moisture content of goose berries, the efficient moisture transport within the sample led to lower values of specific energy consumption (2.622 MJ kg −1 ) and higher microwave drying efficiency (82.94%). An empirical model was employed to fit the experimental data and gave good fit for all experimental runs except microwave finish data. Midilli et al. model gave a best fit when compared to the other basic mathematical models. Microwave finish dried gooseberry samples were lighter in color and had the highest rehydration value. Keywords: Indian Gooseberry, Microwave finish drying, Mathematical modeling, rehydration.