Skip to main navigation menu Skip to main content Skip to site footer
Page Header Logo

Research article

Vol 2 No 1 (2008): Volume 2, Number 1, 2008

Konstanta laju pengeringan daun sambiloto menggunakan pengering tekanan rendah

DOI
https://doi.org/10.22146/jrekpros.550
Submitted
November 11, 2023
Published
June 30, 2008

Abstract

Herbs (traditional medicine) such as sambiloto leaves are senisitive to heat, therefore the drying process of herbs were performed at low-pressure. At low pressure, evaporation of water in the herbs can be carried out at a temperature below 100°C. The low temperature of drying may reduce the destruction of heat-sensitive chemicals inside the herbs. The present study aimed at analyzing the drying rate constant of sambiloto leaves during lowpressure drying. Sambiloto leaves were dried at varied temperature of 30°C, 40°C, and 50°C, and varied pressure of 61 kPa, 48 kPa, and 35 kPa. The water content of sambiloto leaves was reduced from ± 70% to ± 10%. The change in water content was measured after 10, 20, 30, 60, 90, 120, 150 and 210 minutes, by using thermogravimetry technique. The drying-rate constant was calculated using the equation of thin films. The drying-rate constant was 0.01 – 0.0175 min-1. It was observed that the drying-rate increases as the pressure decreases. To predict the change of water content in sambiloto leaves during low-pressure drying process, an empirical equation for the drying-rate constant as a function of temperature and pressure was derived from theexperimental data, kprediction= 0,00075T0,823P-0,021.

References

  1. Bejan, A. 1984. Convection of Heat Transfer. John Willey and Sons. New York.
  2. Brooker, D. B., F. W. Baker-Arkema dan C. W. Hall. 1972. Drying and Storage of Grains and Oilseeds. Van Nostrand Reinhold. New York.
  3. Chakraverty, A. 2001. Postharvest Technology. Science Publisher. Inc. Enfield, USA.
  4. Crank, J. 1975. The Mathematics of Diffusion. Clarendon Press. Oxford.
  5. Drouzas, A. E., E. Tsami and G. D. Saravacos. 1999. Microwave Vacuum Drying of Model Fruit Gels. J.
  6. of Food Eng. 39(2), 117-122.
  7. Kozanoglu, B., A. C. Vazquez, J. W. Chanes and J. L. Patiño. 2006. Drying of Seeds in a Superheated Steam Vacuum Fluidized Bed. J. of Food Eng., 75(3), 383-387.
  8. Lewis, M.J., 2003. Physical Properties of Food Processing System. Ellis Horwood Ltd. Chickester,
  9. England.
  10. Lisdawati, V. 2002. Makalah :Buah Mahkota DewaToksisitas, Efek Antioksidan dan Efek Antikanker
  11. Berdasarkan Uji Penapisan Farmakologi. www.mahkotadewa.com. Didownload tanggal 21 Juni 2007.
  12. Lydersen, A. L. 1983. Mass Transfer in Engineering Practice. John Wiley and Sons. Trondheim.
  13. McMinn. W. A. M., 2006. Thin-layer Modelling of The Convective, Microwave, MicrowaveConvective and Microwave-vacuum Drying of Lactose Powder. J. of Food Eng. 72(2), 113-123.
  14. Mongpraneet, S., T. Abe and T. Tsurusaki. 2002. Accelerated Drying of Welsh Onion by Far Infrared Radiation Under Vacuum Conditions. J. of Food Eng. 55(2), 147-156.
  15. Montgomery, S. W., V. W. Goldschmidt and M. A. Franchek. 1998. Vacuum Assisted Drying of Hydrophilic Plates: Static Drying Experiments. Int. J. of Heat and Mass Trans., 41(4-5), 735-744.
  16. Myers, G. E. 1971. Analytical Methods in Conduction Heat Transfer. McGraw Hill Book Company. New York.
  17. Orizik, M. N. 1980. Heat Conduction. John Willey and Sons. New York.
  18. Pramono, S. 2006. Peningkatan Efektivitas dan Daya Saing Obat Alami Indonesia. Pidato Pengukuhan Jabatan Guru Besar pada Fakultas Farmasi Universitas Gadjah Mada. Yogyakarta.
  19. Rachmawan, O. 2001. Pengeringan, Pendinginan, dan Pengemasan Komoditas Pertanian. Direktorat Pendidikan Menengah Kejuruan, Departemen Pendidikan Nasional. Jakarta.
  20. Yusron, M. 2005. Budidaya Tanaman Sambiloto. Badan Penelitian dan Pengembangan Pertanian, Balai Penelitian Tanaman Obat dan Aromatika. Yogyakarta.