Overview
Meeme and colleagues used Uganda National Bureau of Standards test results for 43 market kombucha products, analysed in 2019 and 2020, to check compliance with the national kombucha specification, and surveyed eight processors and validated a HACCP plan at one producer. Lead, cadmium, arsenic and mercury were measured by ICP-OES after dry ashing. The authors state all products passed the heavy-metal requirements.
Key numbers
- Lead printed as 0.05 mg/l for 42 of 43 products, equal to the specification maximum of 0.05 mg/l (Table 1, pp. 157-158).
- Cadmium 0.001 to 0.002 mg/l in 42 products; arsenic <0.05 mg/l; mercury <0.1 mg/l (Table 1).
- One certified product (C22) is printed with lead 0.5 mg/l and cadmium 0.05 mg/l, which conflicts with the text’s statement that all products passed (Table 1, p. 157).
- HACCP validation samples: lead <0.05, cadmium <0.002, arsenic <0.05, mercury <0.001 mg/L before and after the plan (Table 6, p. 163).
Methods (brief)
Secondary data from the national standards-body database; heavy metals by ICP-OES on ash from dry ashing at 400 C. Detection limits, reference materials and recoveries are not reported. Results are per litre.
Evidence Fitness
Kombucha is a tea-based fermented drink and is used here as a proxy for fermented-beverage-bases (jun and similar bases); the fermented-beverage-bases page is not linked. The results look like reporting limits rather than measured values: lead is printed at the regulatory maximum for almost every product, and the mercury reporting level (<0.1 mg/l) is far above the 0.001 mg/l limit, so the data cannot show mercury compliance. One row (C22) appears misprinted. Per-litre values must not be compared with mg/kg results.