The Cheap Turmeric: Colour Tests, Lead and a Recall Decision
A spice packing unit in Sangli buys 500 kg of turmeric powder from a new trader at ₹175/kg when the usual rate is ₹260/kg. The powder is unusually bright yellow and slightly gritty. Following a rapid screening method, the in-house chemist adds dilute hydrochloric acid to a sample and sees a pink-magenta colour; a second portion, tested with diphenylcarbazide after acid digestion, gives an intense violet colour. Confirmatory analysis by atomic absorption spectroscopy reports lead at 14 mg/kg, against the FSSAI limit of 2.5 mg/kg for turmeric powder. Production records show that 420 kg of this lot was already blended into 1,800 kg of "special garam masala" and sold to three wholesalers in the last ten days; 80 kg remains in store. The owner wants to "just stop using the remaining stock" and say nothing to buyers, because the masala contains only about 23 % turmeric.
1. Interpret the two colour tests and the confirmatory result, and evaluate the owner's argument that dilution to 23 % turmeric makes the problem negligible.
Read the worked answer
Each test is pointing at a different adulterant, and together they explain the price.
Pink-magenta with dilute hydrochloric acid: this is the classic screening reaction for metanil yellow, a non-permitted synthetic dye used to brighten turmeric. It is not a permitted colour for any food, so its presence is a violation regardless of concentration.
Violet with diphenylcarbazide after acid digestion: diphenylcarbazide is a colorimetric reagent for lead, and the result indicates lead chromate, a pigment used to give turmeric a bright yellow appearance. Neither test is confirmatory on its own, because other substances and matrix effects can give false positives, which is why the AAS result matters: 14 mg/kg is more than five times the 2.5 mg/kg limit and converts suspicion into a confirmed non-compliance.
On dilution: 23 % of 14 mg/kg is roughly 3.2 mg/kg if mixing were perfectly uniform, which still exceeds the 2.5 mg/kg limit for the masala. More importantly, spice blending in a small unit is never perfectly uniform, so some portions of the 1,800 kg will contain far more than the average. Lead is a cumulative neurotoxicant with no known safe threshold and children are especially vulnerable; the argument that the consumer eats only a small quantity of a diluted spice is not a defence the unit can rely on. Metanil yellow, being unpermitted, is not addressed by dilution at all.
2. Decide the correct regulatory and commercial action for the 80 kg in store and the 1,800 kg already sold, and justify the difference between a withdrawal and a recall here.
Read the worked answer
This is a recall situation, not a quiet withdrawal. A withdrawal is the removal of product from the distribution chain where the food is still under the business's control or has not reached consumers; a recall is the removal of food that has reached consumers because it is unsafe. Here, 1,800 kg of masala has been sold to three wholesalers and may already be in kitchens and retail shelves, and the hazard is a confirmed exceedance of a contaminant limit plus an unpermitted dye. That engages the FSS Act 2006 obligations on a food business operator to ensure food safety and to inform the authority.
Actions: immediately place the remaining 80 kg on hold and segregate it, labelled as not for sale; use batch codes, invoices and dispatch records to trace the three wholesalers and establish quantities and onward distribution; initiate a formal recall through the FSSAI recall system in line with the food recall guidelines, with the recall class reflecting the health risk; notify the licensing authority and cooperate with its investigation; issue clear communication to wholesalers and, where consumers may hold the product, a public notice identifying the brand, batch and dates; keep all records, samples and correspondence.
Commercially, voluntary and prompt action limits the legal exposure and preserves the business; concealment is itself an offence and, if a sample is drawn independently, the position becomes far worse. The 80 kg held in store should not be blended, sold cheaply or used for any other product.
3. Identify the root cause in the supplier chain and design a receiving and supplier-approval system that would have caught this before blending.
Read the worked answer
The root cause is a purchasing decision: a new, unapproved supplier offering turmeric at about one-third below the going rate, accepted without verification. Adulteration with lead chromate and metanil yellow is a known economic fraud in turmeric precisely because colour is the quality cue buyers use, so price and appearance together were the warning signs.
A workable system:
Supplier approval before first purchase: identity, GST and FSSAI licence of the supplier, a signed specification, and a vendor questionnaire; sample testing of three lots before approval; periodic re-approval based on performance.
Specification and certificate of analysis: each lot to arrive with a COA covering lead, moisture, total ash, acid-insoluble ash, curcumin content and absence of added colour; the COA is evidence, not proof, so in-house checks continue.
Receiving tests on every lot: rapid screening for metanil yellow and lead chromate, plus moisture and ash; a retained sample sealed and stored for the shelf life of the product. Suspect lots are quarantined, not released on verbal assurance.
Periodic confirmatory testing: heavy metals by AAS or ICP-MS on a scheduled basis and on any lot that screens positive, because rapid tests are screening tools only.
Segregation and traceability: approved lots only into production, batch-linked records so any finished product can be traced back to a supplier lot within hours.
Purchasing discipline: buyers must have a documented reason for any price far below the market rate, with supervisory sign-off. Cheapest-first purchasing without technical clearance is the vulnerability to remove.