Tarigan, Silalahi, Muchlisyam 2016 — Factors affecting tin release in canned beverages
Summary
This Indonesian Causal Comparative study measures inorganic tin concentrations in three categories of canned beverages (carbonated drinks, beer, fruit juice) sold on the Medan, North Sumatra market, with the analytical question of whether storage duration to expiry and beverage pH drive tin release from the can lining. The authors quantify tin by air-acetylene flame atomic absorption spectrophotometry at 286.3 nm in 18 samples (9 brand variants in each of two expiry cohorts), report concentrations between approximately 2.5 and 5.8 mg/kg across all categories and cohorts, and conclude that lower pH increases tin release and that newer-expiry cans (more remaining storage time) carry higher tin than older-expiry cans of the same category. All values are well below the EU EC 1881/2006 maximum levels of 200 mg/kg for canned food and 100 mg/kg for canned beverages.
Key numbers
| Brand cohort | 2014 expiry (mg/kg, mean ± SD) | 2015 expiry (mg/kg, mean ± SD) |
|---|---|---|
| Carbonated A1 | 5.77 ± 0.16 | 2.89 ± 0.64 |
| Carbonated A2 | 5.24 ± 0.37 | 2.83 ± 0.45 |
| Carbonated A3 | 4.47 ± 0.31 | 2.81 ± 0.72 |
| Beer B1 | 3.66 ± 0.35 | 2.61 ± 0.77 |
| Beer B2 | 3.62 ± 0.33 | 2.57 ± 0.68 |
| Beer B3 | 3.60 ± 0.40 | 2.50 ± 0.56 |
| Juice C1 | 4.34 ± 0.19 | 2.76 ± 0.39 |
| Juice C2 | 3.95 ± 0.27 | 2.72 ± 0.53 |
| Juice C3 | 3.82 ± 0.39 | 2.71 ± 0.17 |
Methods (brief)
Samples were canned beverages purchased from the Medan retail market in 2015 and grouped by category (carbonated drink, beer, fruit juice), brand within category (A1/A2/A3, B1/B2/B3, C1/C2/C3), and printed expiry date (2014 cohort already past expiry at sampling, 2015 cohort still in date). Tin was quantified by air-acetylene flame AAS at 286.3 nm against tin standards. The expired (2014) cohort thus represents longer can-content contact time at retail; the 2015 cohort represents shorter contact time.
Limitations
The “expiry-2014 versus expiry-2015” framing is a proxy for time-since-canning rather than a direct storage-duration measurement; actual canning dates and storage temperatures are not reported. The journal is a small Indonesian outlet (International Journal of PharmTech Research) with limited indexing; the result is consistent with the well-established acidity-and-storage-time tin-release literature but is not a high-evidence-tier independent confirmation. Sample size is 18 measurements across 9 brand variants and 2 cohorts; per-cell n is small.
Implications
- Certification: Useful B-tier supporting evidence that tin release in canned beverages remains substantially below EU 2023/915 / EC 1881/2006 maximum levels (200 ppm canned food, 100 ppm canned beverages) under typical Southeast Asian market conditions, even past printed expiry. Not sufficient on its own for HMTc threshold setting; complements primary toxicology in benoy1971-tin-toxicity-canned-fruit-juices and the comprehensive ATSDR review.
- Courses: Demonstrates the pH-and-storage-time tin-release relationship that underlies why canned acidic juices and fruit cocktails are the highest-tin canned-food category.