Curcumin, is the primary bioactive compound present in Turmeric attributed with many health benefits. Research has proven that Curcumin has excellent anti inflammatory and anti oxidant properties, improves brain function, and effective in treating diabetes, heart diseases, arthritis, cancer and other neurological disorders. Since usual intake of turmeric doesn’t meet the required levels, Curcumin extracts. Let’s take a look at how Curcumin is extracted and purified as a supplement and the quality control involved in the process.
The Turmeric that we know contains rather low amounts of curcuminoids ( around 3% by weight ). Hence it is subjected through a multitude of processes to procure Curcumin. The solvent extraction process involves ground dry turmeric root treated by a solvent ,which is evaporated under vaccum to get a curcuminoid rich extract called the Oleoresin.
The oleoresin obtained in extraction is subjected to column chromatography to elude the different curcuminoids. These are then run through prep –TLC/ Thin Layer Chromatography to purify the individual curcuminoids. This results in clear separation of the purified curcuminoids.
Alternatively, Cooling Crystallization has also proven effective in isolating and purifying curcumin. This technique employs successive rounds of cooling crystallization using Isopropanol as solvent. This results in purified Curcumin crystals that are subjective to their properties.
The purified curcuminoids are characterized by H-NMR, UV spectroscopy to determine the curcuminoids – Curcumin, DMC and BDMC respectively. Owing to their difference in structures and chemical shifts, they’re profoundly characterized and labelled.
PURITY TESTING TECHNIQUES:
The purified curcumin is the run through HPLC / High Performance Liquid Chromatography using gradient elution. Comparing stock values obtained against Standard values, the purity of curcumin can be determined. Acetone, Ethanol and Ethyl Alcohol have been proven to give the best results in purifying curcumin.
This technique measures the light absorbed by a sample as a function of wavelength. This data is calibrated against standard values to determine the amount of curcumin present in a given sample and hence determine it’s purity.
Commercially available Curcumin often comes with certain impurities like by-products and sometimes adulterated by substances that mimic the qualities of curcumin. Let’s take a look at different methods used to curb adulteration.
Physical Analysis :
The methods involve parameters like solubility, density,texture etc and microscopic observation to detect artificial colorants like metanil yellow, lead chromate, aniline, acid orange, Sudan Red G, yellow soap stone and chalk powder.
Chromatographic techniques :
Thin Layer Chromatography (TLC) is an economic way of testing for certain synthetic and biological contaminants like C.zedoria , C.aromatica by detecting their active components comprising camphor and camphene.
Spectroscopic Analysis :
Spectroscopic techniques like UV, Visible light, Infrared (MIR,NIR), NMR etc.. helps trace spectral signature of synthetic additives and toxic chemicals like Lead and Chromium , used to impart attractive colour to the product. These methods ask for minimal sample usage whilst using non destructive testing.
Biomolecular methods :
Polymerase Chain Reaction (PCR) is often used to determine the biological impurities in a given Curcumin sample. Random Amplified Polymorphic DNA (RAPD) Analysis involves using Sequence Characterised Amplified Region (SCAR) markers to identify the likes of plant based impurities C.zedoria , C.malabarica and more.
Radicarbon dating :
An advanced technique that employs C-14 dating to analyse and detect synthetic curcumin. This method determines the percenrage of C-14 measured in a given sample and determines the source of curcuminiods – natural or synthetic. This is by far the most sophisticated technique that detects with great accuracy.