Vol. 12, Issue 6 (2023)

Author(s):
V Vedasree, N Vinoda, K Lavanya, Y Sirisha, G Ankireddy, T Goutham and G Chanakya

Abstract:
The present experiment was conducted to study the drying characteristics of bitter gourd slices treated at different concentrations of KMS solution and dried at different drying air temperatures in a tray dryer. Blanched bitter gourd slices were treated with potassium meta bisulphate (KMS) at three different concentrations of 0.2, 0.3 and 0.5%. The treated bitter gourd slices were spread over the trays in a single layer in a tray drier and dried at different temperatures (50, 55 and 60 ºC) until a constant weight was attained. After drying, the samples were taken out and drying characteristics and physical properties such as rehydration ratio, bulk density, particle density and ash content were determined. The results showed that as the drying air temperature increased the drying time reduced. The drying time observed about 285 min to reduce the moisture content of bitter gourd slices from 1698.56 to 5.75% (d.b) pretreated at 0.2% KMS solution and dried at air temperature of 50 ºC. As the temperature of drying air was increased to 55 and 60 ºC for 0.2% KMS concentration of pretreatment, drying time observed nearly 285 and 240 min respectively to reach final moisture content. The maximum rehydration ratio of 6.8 was found for sample dried at 60 ºC and 0.5% KMS solution. Bulk density of the slices increased as the drying air temperature decreased from 60 to 50 ºC. Lowest particle density (0.27 g/cc) and lowest ash content (4.25) were observed for the samples dried at 50 ºC, 0.2% KMS concentration. Finally it was concluded that lowest drying time and high drying rate was observed at 60 ºC and 0.2% KMS solution.