Effect of different drying treatments on concentration of curcumin in raw curcuma longa l.

Abstract

Curcuma longa L., commonly known as turmeric, is a member of the ginger family (Zingiberaceae), native to Southwest India. Curcumin is the active ingredient of the turmeric. In traditional Indian medicine, turmeric has been used to treat stomach and liver ailments, as well as topically to heal sores, for its supposed antimicrobial property. The curcumin is believed to have a wide range of biological effects including anti-inflammatory, antioxidant, antitumor, antibacterial, and antiviral activities, which indicate potential in clinical medicine. In conventional processing of turmeric, raw turmeric rhizomes boiled and dried under direct sunlight for 1-4 hrs and 25-30 days, respectively although which is highly sensitive to the heat and sunlight. This work described the effect of different drying treatments including shade, direct sunlight, solar dryer, convection oven and hot-air drying on the concentration of curcumin. The Reflux method was used to analyse the concentration of curcumin in turmeric powder prepared under different drying treatments. The results had shown that without boiling turmeric rhizomes took too much time to reach the final moisture contents below 10% in all drying treatments which was not feasible economical and hygienically. The optimum conditions for drying of turmeric rhizomes were 1 hr boiling and drying at 70oC in hot-air dryer.