Hariono et al. 2023 — Metals in Indonesian soy milk processed in aluminum and stainless-steel cookers

Hariono and colleagues compared proximate quality and metal content in soy milk from an Indonesian producer after cooking in aluminum versus stainless-steel vessels. The paper reports very high measured concentrations for Pb, Cu, Zn, Hg, and As in finished soy milk, with stainless-steel processing lowering Pb, Cu, and Hg relative to aluminum processing but increasing Zn and As. The values are routeable as a small cookware-comparison occurrence study for soy milk, but they should be treated cautiously because the paper reports only one value per treatment, does not disclose replicate statistics or LODs, and appears to use comma decimals in the Indonesian format.

Key numbers

Table 1 and Table 2 report the same metal concentrations in finished soy milk, in ppm, after processing with two cooking-vessel materials:

The paper compares Pb to an Indonesian BPOM ready-to-consume beverage limit of 0.05 mg/kg and states that both treatments exceed that threshold. It compares Cu to a cited minimum/normal reference range of 0.8-1.2 ppm and states that both treatments exceed that range. It compares Hg to a cited beverage threshold of 0.005 ppm and states that both treatments exceed that threshold. The paper states that the maximum As limit is 0.05 mg/kg; both reported As values (0.079 and 0.107 ppm) exceed that cited limit.

The same tables report proximate and pH values: total protein 2.590% in aluminum-pan soy milk and 2.340% in stainless-steel-pan soy milk; fat 0.190% and 0.47%; lactose 3.800% and 4.16%; solid non-fat 7.15% and 7.720%; pH 6.943 and 6.710.

The abstract also says cooking water contributed Pb 0.055 ppm, Cu 0.044 ppm, Zn 0.028 ppm, and As 0.156 ppm. The abstract lists “Pb, Cu, Zn, Hg, and As” but provides only four numeric water-contribution values; the missing fifth value is a source-side ambiguity, not filled in here.

Methods (brief)

The study used a descriptive comparison of soy milk processed in aluminum and stainless-steel cooking vessels. The sample was soy milk from one industrial-scale producer in Sumbersari District, Jember Regency, with testing conducted at the Bioscience Academic Implementation Unit of Jember State Polytechnic on July 26, 2022. The paper states that metal analysis covered Cu, Pb, As, Cr, Zn, and Hg in soy milk, with atomic absorption spectroscopy using the Shimadzu Atomic Absorption Cook Book method; Cr is named in methods but not reported in the result table, so this source page does not list Cr as a measured result. The methods section does not disclose instrument model, digestion details, LOD/LOQ, blank handling, recovery, certified reference material, or replicate statistics.

Implications

This source may support a narrow context note for soy milk and soy-based plant milk where cookware or process water can dominate the measured metal profile. It is not sufficient by itself for a benchmark distribution because the sample structure is a two-condition processing comparison from one producer, not a market survey. The very high Pb and Cu values should be preserved as source facts but should not be generalized without corroborating Indonesian soy-milk occurrence studies or reanalysis with clearer QA/QC reporting.

Wiki pages this source may touch

• plant-milks-soy-based
• soy-products
• soy-milk
• soy
• lead
• copper
• zinc
• mercury-total
• arsenic-total

Verification notes

PDF extracted 2026-05-31 from the auto-fetched queue. Metadata are taken from the article front page: Aceh Nutrition Journal, DOI 10.30867/action.v8i4.925, received July 26, 2022, accepted May 18, 2023, published December 5, 2023. The filename was fetched under an aluminum-in-soy-products query, and the actual source is a soy-milk finished-product cookware comparison. Table 1 and Table 2 repeat the same metal values; the table transcription here preserves the source’s comma decimals as decimal points. The paper uses “US” in one English methods sentence where the intended analyte is arsenic (As); this page treats it as total arsenic (tAs) because the abstract, Indonesian abstract, and tables consistently report As without speciation. Mercury is likewise total mercury (tHg), not methylmercury. Cr is named in methods but absent from results and therefore excluded from the metals frontmatter. The matrix terms beverage and food-processing are existing broad descriptors used to avoid inventing a source-specific cookware-comparison matrix while still preserving the study design.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.