Curcuma longa rhizome is a well-known herb that has been traditionally used in many countries. In
Thailand C. longa have been added into the national drug list and widely used for treatment of dyspepsia
instead of simethicone. Curcuminoid content in C. longa rhizome was used for control the quality of the raw material as described in Thai
Herbal Pharmacopoeia (THP) [1]. The extraction method mentioned in THP was time consuming,
it was performed by macerated C. longa powder in tetrahydrofuran for 24 hr before analyzed with UV spectrophotometer. This
study aimed to investigated the novel extraction method which are faster but still
precise and accurate as well as the conventional method. Three different extraction
methods including reflux extraction (RE), microwave assisted extraction (MAE) and
ultrasonic assisted extraction (UAE), have been investigated and compared with the
conventional method. It was found that MAE (900W, 30 s on/30 s off for 3 cycle) and
UAE (90W, 37 kHz for 30 min) were able to extract curcuminoids as well as maceration
for 24 hr, while RE for 30 min gave lower amount of curcuminoid content. Some parameters
of MAE were optimized including power, cycle and extraction time. The optimized conditions
were then evaluated on their intraday and interday precision in 40 samples both raw
materials and commercial products. The result showed that the most appropriate conditions
of MAE for extraction of curcumionoids were 900W, 25 s on/30 s off for 4 cycle which
showed %RSD at 0.55% and 1.23% for intraday and interday precision, respectively.
MAE was able to use as an alternative extraction method to the conventional one. The
method is faster easier and more suitable for the routine analysis of curcuminoid
content than the conventional method.
Fig. 1: curcuminoid content (%)
[1] Department of Medical Sciences. Thai Herbal Pharmacopoeia, 1. Bangkok: Prachachon
Co; 1995
