Increasing energy efficiency of the Cissus quadrangularis drying by hot air fluidization technique

Abstract

The aim of this paper is to increase energy efficiency by reducing specific energy consumption (SEC) during Cissus quadrangularis drying. The fresh sample, with a high moisture content of 90 ± 2 % wet basis (w.b.), was dried by hot air Fluidized bed technique at temperatures of 90, 110, 130 and 150°C to a final moisture content of 5 % (w.b.) and then was compared to the results of tray drying at a low temperature of 50°C, following a method by Tha Sae Hospital in Chumphon province, Thailand. The drying kinetic result revealed that fluidization drying had a higher rate of water removal than the tray drying method. That rate directly correlated with the drying temperature; it increased with an increase of drying temperature. With the increasing of the rate, it resulted in a decreasing of SEC. Although using a drying temperature of 150°C had the highest rate of water removal and subsequently had the lowest SEC, it negatively affected the antioxidant activity of the sample. To dry Cissus quadrangularis with the lowest SEC as possible, it should be dried by hot air fluidization at a drying temperature of 110°C. At this drying condition, there is still a high rate of water removal and a low effect of the desired qualities of the sample.