Assessment of lead levels and microbial quality in selected spices sold in Onitsha Markets, Anambra State, Nigeria

Background: Spices and seasonings are widely consumed food additives valued for their flavoring, preservative, and health-promoting properties. However, contamination by heavy metals and microorganisms remains a significant food safety concern, particularly in open-market environments where handling and storage conditions may be inadequate.
Objectives: This study assessed the level of adulteration in selected spices and seasonings sold in major markets in Onitsha, Anambra State, Nigeria, with emphasis on lead (Pb) contamination and microbiological quality.
Materials and Methods: A laboratory-based experimental and analytical study was conducted on thirty (30) samples comprising ginger, turmeric, garlic, curry, and ground pepper obtained from vendors in Main Market, Ochanja Market, and Relief Market. Lead concentration was determined using Atomic Absorption Spectrophotometry (AAS) following acid digestion. Microbiological analyses included total bacterial count (TBC), total coliform count, and fecal coliform determination using standard microbiological techniques. Results were compared with established international food safety standards.
Results: Lead was detected in most samples at low concentrations ranging from non-detectable levels to 0.056 mg/kg. Turmeric recorded the highest Pb concentration (0.056 mg/kg), followed by ginger (0.042 mg/kg) and ground pepper (0.010 mg/kg), while garlic and curry showed negligible levels. All detected concentrations were substantially below Codex Alimentarius permissible limits, indicating compliance with international safety standards. Microbiological analysis revealed total bacterial counts in all samples, with ginger recording the highest counts (1.5 × 10^⁶–1.8 × 10^⁶ CFU/g) and garlic the lowest (1.0 × 10^³–1.3 × 10^³ CFU/g). Total and fecal coliforms were absent in ginger, turmeric, garlic, and ground pepper samples but were detected in all curry samples, with fecal coliforms occurring in 50% of the curry samples.
Conclusion: The analyzed spices and seasonings were safe with respect to lead contamination. However, the occurrence of coliform contamination in curry samples indicates deficiencies in hygiene and sanitary practices. Strengthening food safety measures and routine monitoring is essential to ensure the microbiological safety of spices and seasonings sold in local markets.