Turmeric is one of my favourite and most used spice or herb for a health issue, such as painful joints or for general health support. It’s benefits are so broad, that I am careful about listing too much of them at once when talking to someone who is new to natural health care. The fact that it works so well for so many issues and is cheap, can make some people skeptical.
In the last several years, turmeric has been discovered by the western alternative health world and as a consequence, its use has skyrocketed. Of course, in the Indian, Chinese and Asian cultures, it is one of the most important spices.
However, it can be adulterated easily by unscrupulous venders. An obvious one, of course is to stretch the supply and add weight with fillers or dangerous colour enhancers. You can see the problem if you use turmeric more for health rather than for cooking. You think you are getting curcumin rich turmeric…but is it?
Even with turmeric powder intact of its curcumin, contaminants may be ground wood dust, lead chromate, cadium and often metanil yellow to colour the chalk or wood filler. In October, 2013 the FDA (US Food and Drug Administration) tested the Pran brand imported from Bangladesh and found it contaminated with lead. More than 90% of spices are imported to the US and Europe from various sources.
Samples tested in one US city found various contaminants with about a third contaminated with salmonella. A problem with any spice or herb found in the supermarket is that the country of origin is not required on the label.
In 2009 a recall was initiated on the supplement Fortodol (aka Leppin Miradinan). An unscrupulous Mexican supplement manufacturer whose product was also sold in California, contaminated the raw turmeric supplies he used with Nimesulide, a powerful anti-inflammatory drug that has caused liver damage and is since banned in all European, Scandinavian countries and the US.
I wish I knew of a good Indian supplier of high quality, pure turmeric – it certainly would be cheaper. But frankly, I find it increasingly difficult to trust suppliers from Pakistan, Bangladesh , India (exports 60% of world trade) or China, not because I assume all are unscrupulous but because it is a known problem that neither hygienic nor safety and health concerns are high on the priority list. I am sure there are good ethical suppliers, but how do you know? The cheap bags and jars of spices are not worth the risk to me since I use it almost daily, not just now and again for a curry. Purity standards do exist in those countries, but sadly, bribes are the order of the day.
True turmeric is a vibrant deep yellow with orange undertones to almost a yellowish pumpkin orange. Although it stains bright yellow, the powder itself is never bright yellow.
I buy certified organic from a health food shop. It’s been tested for curcumin content and impurities. If you purchase supplement form, use the same criteria: look for certification of purity and curcumin content and ask where they are produced before purchasing.
Here is a simple water test for chalk, wood powder or other adulterants that may float:
- Pour a little warm water in a clear glass.
- Drop on the surface about a half teaspoon WITHOUT stirring.
- Allow to sit undisturbed for about 20 minutes.
After about 10 min you should see a sediment at the bottom of the glass and slightly cloudy but yellow water. After another 15 min or so, it will be very clear yellow as you can see in the photo. If the water remains rather cloudy, then most likely chalk has been added as a filler and if anything is floating on the top then it is probably wood dust or other impurities.
The hydrochloric acid test:
- Mix a small amount of turmeric with an equal amount of water.
- Add a few drops of concentrated hydrochloric acid (from Amazon or local pharmacy). Effervescence (fizzing action) will indicate the presence of chalk or yellow soapstone powder.
The acid test for metanil yellow:
- Mix half a teaspoon with 4 teaspoons of water.
- Add a few drops of a strong household vinegar such as distilled concentrated (white) vinegar. If it shows pink, purple or violet, metanil yellow is present.
Variation with hydrochloric acid:
- Proceed as above but add a few drops of hydrochloric acid. If it instantly turns pink, but disappears on dilution with more water, it is pure turmeric. If the colour persists, metanil yellow is present.
Metanil yellow is a carcinogen if used over a prolonged period of time. Reports include testicular, bladder and kidney cancers. Metanil yellow, also known as Acid Yellow is commonly used in India though not approved (nor enforced much) for human consumption. It is normally used for industrial dies and paints. Illegally used in imported noodles, crackers and snacks, it gives a bright yellow to the product. Designated with the European E number E105 it is forbidden for use in Europe and North America.
I know of no tests for lead chromate other than visually. The brighter yellow it is, the risk is higher that it has been adulterated with it. True turmeric is a vibrant deep yellow with orange undertones to almost a yellowish pumpkin orange. While researching for this article, I have found information that samples tested in Bangladesh of the whole boiled and dried turmeric rhizome contained even higher amounts than the dried powder. This particular form may be more popular in India as I have never seen it in health food shops, but it may be in Indian/Asian food shops.
None of these tests, however prove how much curcumin is in the turmeric. In unadulterated turmeric it can range from 1% to 5% and slightly more percent. Reputable suppliers are willing to offer a certified lab report on the amount of curcumin.
So there you have it. Now go and test your turmeric!
More related articles:
How to Expose Food Adulteration One of the better of several references on adulteration.