Influence of drying methods on the quality of Orthosiphon stamineus extract


  • Cher Haan Lau Institute of Bioproduct Development, Universiti Teknologi Malaysia
  • Lee Suan Chua Institute of Bioproduct Development, Universiti Teknologi Malaysia



Orthosiphon stamineus, LC-MS/MS, herbal extract, rosmarinic acid, eupatorin


The interest in herbal products is tremendously increasing in recent years, probably due to their health promoting benefits. Drying is one of the important processes in herbal extract preparation. Therefore, this study evaluated the effects of drying methods on the quality of Orthosiphon stamineus (OS) extract. The OS extract was concentrated by a centrifugal concentrating system operated at three different modes (Infrared (IR), IR-Heat and Heat), vacuum evaporator (VE) and oven dryer. The phytochemical profiles of the dried extracts were analysed by LC-MS/MS. The oven-dried OS extract showed the highest yield (26.2%), followed by heat-dried, IR-heat-dried, IR-dried and VE-dried. The VE-dried extract showed the highest reduction of extract quality in term of its phytochemical content, particularly for the major compounds such as caffeic acid, eupatorin, eupatorin derivative, myricetin, rosmarinic acid, rutin and sinensetin. The drying kinetic for IR, heat and IR-heat methods were fitted well into Page model with R2>0.99. This research concluded that the selection of drying method is important because it will affect the phytochemical profile of the plant extract significantly.


Ameer, O. Z., Salman, I. M., Asmawi, M. Z., Ibraheem, Z. O., and Yam, M. F. (2012). Orthosiphon stamineus: Traditional Uses, Phytochemistry, Pharmacology, and Toxicology. Journal of Medicinal Food, 15(8), 678-690.

Bensebia, O., and Allia, K. (2015). Drying and extraction kinetics of rosemary leaves: Experiments and modeling. Journal of Essential Oil Bearing Plants, 18(1), 99-111.

Conway, B. R. (2007). Solid dosage forms. In Gad, S. C. (Ed.) Pharmaceutical Manufacturing Handbook: Production & Processes (pp. 233-265). New Jersey: John Wiley & Sons, Inc.

Chua, L. S., and Lau, C. H. (2016). Reflux extraction and column chromatography for rosmarinic acid-rich fraction from Orthosiphon stamineus. The Natural Products Journal, 7(1), 30-36.

Darvishi, H., Asl, A. R., Asghari, A., Azadbakht, M., Najafi, G., and Khodaei, J. (2014). Study of the drying kinetics of pepper. Journal of the Saudi Society of Agricultural Sciences, 13(2), 130-138.

Gallo, L., Ramírez-Rigo, M. V., Piña, J., and Bucalá, V. (2015). A comparative study of spray-dried medicinal plant aqueous extracts. Drying performance and product quality. Chemical Engineering Research and Design, 104(Supplement C), 681-694.

Krishnamurthy, K., Khurana, H. K., Soojin, J., Irudayaraj, J., and Demirci, A. (2008). Infrared heating in food processing: An overview. Comprehensive Reviews in Food Science and Food Safety, 7(1), 2-13.

Li, Y.-h., Qi, Y.-r., Wu, Z.-f., Wang, Y.-q., Wang, X.-c., Wang, F., Yang, M. (2017). Comparative study of microwave-vacuum and vacuum drying on the drying characteristics, dissolution, physicochemical properties, and antioxidant capacity of Scutellaria extract powder. Powder Technology, 317, 430-437.

Mauer, L. J., and Bradley Jr, R. L. (2017). Moisture and Total Solids Analysis. In Nielsen, S. S. (Ed.) Food Analysis (pp. 257-286). USA: Springer.

Michailidis, P. A., and Krokida, M. K. (2014). Drying and dehydration processes in food preservation and processing. In Bhattacharya, S. (Ed.) Conventional and Advanced Food Processing Technologies (pp. 1-32). New Jersey: John Wiley & Sons, Ltd.

Panceri, C. P., Gomes, T. M., De Gois, J. S., Borges, D. L. G., and Bordignon-Luiz, M. T. (2013). Effect of dehydration process on mineral content, phenolic compounds and antioxidant activity of Cabernet Sauvignon and Merlot grapes. Food Research International, 54(2), 1343-1350.

Sandu, C. (1986). Infrared Radiative Drying in Food Engineering: A Process Analysis. Biotechnology Progress, 2(3), 109-119.

Senevirathne, M., Kim, S.-H., Kim, Y.-D., Oh, C.-K., Oh, M.-C., Ahn, C.-B., et al. (2010). Effect of far-infrared radiation drying of citrus press-cakes on free radical scavenging and antioxidant activities. Journal of Food Engineering, 97(2), 168-176.

Thakur, L., Ghodasra, U., Patel, N., and Dabhi, M. (2011). Novel approaches for stability improvement in natural medicines. Pharmacognosy Reviews, 5(9), 48-54.

WHO (2017). WHO guidelines on good herbal processing practices (GHPP) for herbal medicines. Geneva: World Health Organization.