Surveillance on quality of turmeric powders vis a vis curcumin content and presence of extraneous color s from city markets of India

Sumita Dixit (1) , Shakendra Purshottam (1) , Subhash K Khanna (1) , Mukul Das (1)

1 CSIR Indian Institute of Toxicology Research

Curcumin, the principal curcuminoid of turmeric is responsible for its yellow colour and serves as a measure of quality of turmeric. The Prevention of Food Adulteration (PFA) Act of India allows only Curcuma longa L. for the production of turmeric powder and prohibits addition of any foreign matter/ artificial colour but does not specify minimum curcumin limit. Therefore, the present surveillance has been undertaken to study the quality of loose versus branded turmeric powders vis a vis curcumin content and presence of unwarranted extraneous colours from city markets of India using a newly developed 2D-HPTLC method. Our results show that curcumin content in branded samples ranged from 2.17 to 3.68 % while non-branded samples had 0.26 to 2.65%. Though none of the branded turmeric powders contained artificial colours, 17% of loose powders showed presence of extraneous colour-metanil yellow, in the range of 0.99-8.55 mg g-1 which may pose health threats. Low curcumin content in the analysed samples may be due to mixing of other curcuma species or their curcumin depleted matrices and foreign starches as cheaper alternatives. This is supported by the fact that major Indian turmeric trade types are known to possess curcumin contents ranging from 2.1-8.6 %, with an average of 4.79%. There is thus an urgent need to prescribe realistic curcumin limits for turmeric powder otherwise there is no obligation on the part of traders to stick to any minimum levels and consumers shall keep on getting this nutrient depleted household spice.

Mots clés: Life Sciences

Sumita Dixit, Shakendra Purshottam, Subhash K Khanna, Mukul Das. Surveillance on quality of turmeric powders vis a vis curcumin content and presence of extraneous color s from city markets of India. Food Additives and Contaminants, 2009, 26 (09), pp.1227-1231. ⟨10.1080/02652030903016586⟩. ⟨hal-00573921⟩