Evaluation of Turmeric (Curcuma longa Linn.)
and its Extracts from Indian Market
Kilambi Pundarikakshudu*, Priya A Shah, Pooja D Shah and Anu V Patel
Department of Pharmacognosy, L J Institute of Pharmacy, India
Submission: May 1, 2018; Published: August 17, 2018
*Corresponding author: Pundarikakshudu K, Department of Pharmacognosy, L J Institute of Pharmacy, Between Sarkhej Circle and Kataria Motors, SG Road, Ahmedabad- 382210, India, Tel: +91-79-29296421;+91 7600568631; Email: [email protected]
How to cite this article:Kilambi P, Priya A S, Pooja D S, Anu V P. Evaluation of Turmeric (Curcuma longa Linn.) and its Extracts from Indian Market. J
Complement Med Alt Healthcare. 2018; 6(5): 555700. DOI: 10.19080/JCMAH.2018.06.555700
Turmeric, (Curcuma longa), has been used for its coloring, flavoring, and digestive properties. It has antibacterial, anti-tumour, anti-inflammatory, anti-diabetic and anti-oxidant activities. It is also highly valued as a cosmetic. The main chemical constituents responsible for these activities are phenolic curcuminoids. With rapid advances in Nutraceuticals, the herbal drug industries are increasingly resorting to employing standardized herbal extracts in the formulations. But the extracts supplied by different manufacturers were sometimes found to be completely lacking in quality. Hence, it was decided to prepare the extracts and oleoresins of turmeric and compare them with the marketed samples. Turmeric powder was purchased from local market and water extract and alcoholic extract (turmeric oleo resin) were prepared in our laboratory. Different samples of turmeric powder, turmeric oleoresin and water extract prepared in our laboratory were analyzed by two different spectrometric methods; one by direct measurement of the colour at 425nm and the other by development of color with boric acid and measuring the color at 540nm. We found colorimetric method more suitable as it is very specific to curcumins. Marked differences in curcumin content (ranging from 1.0 to 45 %) were noted in different market samples. These may be due to various factors such as improper extraction method, wrong choice of solvents and excessive addition of diluents etc.
Turmeric (Curcuma longa Linn.) is a dietary food item in the oriental cuisines and is claimed to have a number of medicinal properties such as anti-inflammatory, anti-oxidant and anti-cancer activities. The color and the medicinal activities of turmeric are due to a phenolic compounds collectively known as curcumins .
Curcumin is proving to be a potential drug molecule due to its multifarious activities and its freedom from toxicity [2,3]. Number of studies on designing of various formulations of curcumin are underway . These formulations employ either pure curcumins or standardized extracts. The curcumins in the extracts and powders are analyzed employing different methods such as HPLC, Spectrophotometric  and HPTLC [6,7] methods. The present study was undertaken to evaluate different powder samples and extracts of turmeric available in the market along with the extracts prepared in our laboratory by employing spectrophotometric methods.
Pure curcumin reference standard was gift from Dishman Pharmaceutical Ltd, Ahmedabad. Turmeric powder was procured from local market and various samples of turmeric oleoresins
were procured from different commercial suppliers. Turmeric
oleoresin was prepared by soxhlet extraction using ethanol as solvent and water extract by distilled water. All the chemicals used for analysis were of analytical grade. Spectrophotometric measurements were done on a Shimadzu double beam spectrophotometer model no 1601 using pair of matched quartz cell. All the experiments were carried out in triplicates.
Stock solution of curcumin (100μg/mL) was prepared by dissolving 10mg in 100mL ethanol. Aliquots of 0.2, 0.4, 0.6, 0.8, and 1.0mL were transferred in 10mLvolumetric flasks and volume was adjusted with ethanol to produce the standard solutions of 2, 4, 6, 8 and 10μg/mLconcentrations. Absorbance of all these solutions was taken at 425nm using ethanol blank.
Aliquots of 0.25, 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mL above stock solution was transferred in 10mL volumetric flask and evaporated to dryness in water bath. To each of these, added 1mLof 6 % boric acid solution and the volume adjusted to the mark with glacial acetic acid to produce 2.5, 5.0, 10.0, 20.0, 30.0, 40.0 and 50.0μg/mL of solutions. Blank was prepared as above
omitting the aliquots of curcumin stock solution, Absorbance of
each of these solutions were measured at 540nm against blank.
One gram of each sample was extracted completely in ethanol
and filtered; volume was adjusted to 100 mL with ethanol. After
suitable dilution of this solution with ethanol, the content of
curcumin was analyzed by the methods described above.
Curcumins were found to obey Beer’s law between
concentration ranges of 2-10μg/mL in spectrophotometric
method and 2.5-50μg /mL in boric acid method. Powder samples
of turmeric showed curcumins ranging from 4. 0-4.5 % w/w.
These observations are consistent with the reported literature.
Water extractive values were found to be 20.0% w/w. But this
extract was found to be very poor in curcumin content. It had as
low as 0.4%. w/w of curcumin. This is expected as curcumins are
not known to be soluble in distilled water.
Alcoholic extraction yielded 12.0% w/w extract which is
deep yellow, resinous and oily in nature. This oleoresin extract
was found to be very rich in curcumins (35-45% w/w). Turmeric
extracts from market were also analyzed by the two methods.
They differed in their physical appearance and color. Some of
them were claimed to contain as high as 25% curcumins by
the suppliers. However, it was noted that these samples have
very low amounts of curcumins. The data of the analyses are
presented in Table 1
Curcumins available in the market were found to be 79%
to 95% pure. All these samples and the reference curcumins
exhibited three major spots on TLC when developed in
chloroform: methanol (25: 1). It is evident from the data in table
that direct spectrophotometric method gave slightly higher
results as compared to the results with boric acid method.
Boric acid method is specific for curcumins whereas some other
closely shaded colors might also have added to the yellow color
in ethanol. This is possible as no purification step is involved in
the analysis and ethanol extract was directly taken for analysis.
Hence, we opine that boric acid method should be preferred to
The reason for varying amounts of curcumins noted
especially in the extracts may be improper selection of the
solvent. It is possible that water is employed for the extraction in
stead of the organic solvents like ethanol/acetone/ethyl acetate.
Many manufactures insist on a free flowing powder form of
the herbal extracts for convenience of formulation. As a result,
in majority of cases, diluents like lactose, dextro-mannose, dicalcium
phosphate etc are added to the extracts thus ultimately
resulting in dilution of the active ingredients
Thus, our studies highlight the discrepancies in the quality
of extracts which are, of late, widely employed by a number of
herbal drug manufacturers. This study also further emphasizes
the need to evolve uniform S O Ps for preparation and evaluation
of herbal extracts.