Vaishali & Negi 2020 — Lead and cadmium in tomato ketchup from Delhi NCR street vendors
This short research article reports Pb and Cd concentrations in 12 tomato ketchup samples collected from street food vendors across four locales in the Delhi NCR region of India. Lead was detected in samples from three of four locales, with mean concentrations in Delhi (0.183 ppm), Noida (0.096 ppm), and Faridabad (0.089 ppm) all exceeding the FAO/WHO Codex limit of 0.05 mg/kg; only Gurugram samples (0.031 ppm mean) fell below. Cadmium was below detectable limit in all 12 samples.
Key numbers
Pb concentrations by locale (mg/kg, wet weight, mean ± SD):
- Delhi: 0.183 ± 0.11 (range 0.10–0.311)
- Noida: 0.096 ± 0.08 (range BDL–0.148)
- Faridabad: 0.089 ± 0.15 (range BDL–0.266)
- Gurugram: 0.031 ± 0.05 (range BDL–0.093)
Cd: BDL in all 12 samples across all four locales.
FAO/WHO Codex limit for Pb in tomato products: 0.05 mg/kg (at time of study). ANOVA across locales: not significant (p = 0.42).
n = 12 samples (3 per locale). Method: Atomic Absorption Spectrophotometry (AAS). No LOD/LOQ values reported.
Methods (brief)
Samples were collected in sterilised sealed glass containers from street vendors and transported to the laboratory within two days. Digestion and analysis by AAS. Statistical analysis by one-way ANOVA in Microsoft Excel. No LOD or LOQ values are specified, and BDL is not numerically defined; this limits quantitative utility. The study does not distinguish branded vs. unbranded ketchup or report processing/storage conditions.
Implications
Certification: The Delhi, Noida, and Faridabad mean Pb values exceed the Codex limit; this is a small-n study in an informal market setting in India and carries B-tier weight. It provides contextual evidence that tomato ketchup can concentrate Pb above regulatory thresholds depending on sourcing and handling, but does not anchor HMT&C threshold setting on its own.
Courses: Useful illustration of urban-market lead burden in processed condiments; suitable for modules on informal supply-chain contamination pathways.
App: Supports flagging ketchup/tomato sauce as a Pb-relevant product category; Cd signal here is null (BDL), consistent with tomatoes being a low-Cd matrix.