Shamsani et al. 2019 — Pb, Cd and As in Malaysian-market instant noodles

Shamsani et al. measured lead, cadmium, and total arsenic in seven brands of commercially popular instant noodles purchased from the Malaysian retail market. Each sample combined noodles plus the accompanying seasoning/flavouring powder, homogenized and dry-ashed before ICP-MS analysis. All seven samples carried detectable Pb, Cd, and As. Two of the seven samples exceeded the Malaysian Food Regulation 1985 maximum permitted level of 2 mg/kg for Pb (samples coded A and C, at 2.94 and 2.52 mg/kg respectively); all seven samples exceeded the Codex Alimentarius (CXS 193-1995) Pb maximum of 0.2 mg/kg used by the authors as a cereal-grain comparator, and three samples exceeded the Codex Cd maximum of 0.2 mg/kg used as a wheat comparator. No Codex maximum was applied to As. Cd ranged 0.03–0.37 mg/kg and total As 0.25–0.81 mg/kg across the seven samples; no sample exceeded the Malaysian Food Regulation 1985 ceilings of 1 mg/kg for Cd or As.

Key numbers

Sample-by-sample mean concentrations (Table I, p. 144; mg/kg = ppm; values reported by the authors as mean concentrations for each brand-flavour sample; sample identifiers are anonymised letter codes A–G in the source, not brand names):

* exceeds Malaysian Food Regulation 1985 maximum (Pb 2 mg/kg in all food, preserved and salted except pickles). # exceeds Codex Alimentarius CXS 193-1995 maximum (Pb 0.2 mg/kg in cereal grains; Cd 0.2 mg/kg in wheat) — no Codex ceiling applied to As for this food type.

Ranges (Results, p. 144): Pb 0.27–2.94 mg/kg; Cd 0.03–0.37 mg/kg; As 0.25–0.81 mg/kg across N=7.

Regulatory comparators used by the authors (Table I, p. 144):

Compliance summary (Results and Discussion, pp. 144–145): Against Malaysian Food Regulation 1985, only Pb exceeded the permitted level — in 2 of 7 samples (A, C). Against the Codex cereal-grain/wheat comparators, all 7 samples exceeded the Pb ceiling and 3 of 7 (A, C, E) exceeded the Cd ceiling. No Codex As limit was applied to instant noodles in this paper.

Cross-study comparison narrative (Discussion, p. 144): Authors compare against Jothi & Uddin 2014 (Bangladesh, N=5; Pb 1.17–1.67 mg/kg; Cd 0.53–0.82 mg/kg; As 0.17–0.41 mg/kg), Onyema et al. 2014 (Nigeria, N=7; Pb 0.025–0.106 mg/kg; Cd 0.001–0.008 mg/kg), Emumejaye et al. 2016 (Nigeria, N=8; Pb n.d.–0.55 mg/kg; Cd n.d.–0.01 mg/kg; As n.d.–0.14 mg/kg), and Tajdar-oranj et al. 2018 (Iran, N=27; Pb 1.004–1.57 mg/kg; Cd n.d.–0.34 mg/kg). The Malaysian Pb maximum (2.94 mg/kg) is higher than the maxima reported in any of those four comparator studies; the Malaysian Cd maximum (0.37 mg/kg) is comparable to the Iranian study and higher than the two Nigerian studies but lower than the Bangladesh study; the Malaysian As range (0.25–0.81 mg/kg) is higher than the Bangladesh and one Nigerian study.

Methods (brief)

Seven instant-noodle samples (each comprising the dry noodle plus the accompanying seasoning and flavouring powder) were homogenized in a food blender after soaking in water, then 1 g aliquots were dry-ashed at 450 °C for 1 hour and 480 °C for 4 hours until a white/grey residue was obtained. The residue was dissolved in 5 mL of 0.24 M nitric acid, made up to 25 mL in distilled water, and filtered through 0.45 µm Whatman filter paper. Analysis used a Perkin Elmer Elan DRC-e ICP-MS with a 6-point calibration (5, 10, 20, 50, 100, 300 ppb) and the SRM 1640a reference material for lead, cadmium, and arsenic; the authors report calibration curve fit ±0.999 and “good recoveries” without printing recovery percentages. Concentrations were converted to a sample dry-mass basis using [(A × B) / W] × C, where A is the digested-sample volume, B the dilution factor, C the ICP-MS-measured concentration in µg/mL, and W the original sample weight in grams.

Speciation: arsenic is reported as total arsenic; no inorganic/organic speciation. Mercury, nickel, chromium, tin, antimony, aluminium, and uranium were not measured. The paper does not analyse noodles and seasoning separately; the values represent the noodle-plus-seasoning composite on a dry-ashed basis.

Limitations

• Extended-abstract format (~4 pages including the title page) rather than a full research article — methodological detail (digestion blank values, LODs/LOQs, recovery percentages, replicate counts per sample, sample weighing precision) is not reported. Evidence tier assigned as B reflecting the conference-abstract publication route and limited methodological transparency, not flaws in the underlying chemistry.
• N=7 is small; no statistical inference about the Malaysian instant-noodle market as a whole can be drawn from this sample size. Brand selection is “commercially popular” without sampling-frame documentation.
• The paper analyses noodles and seasoning together as a single homogenate. Because instant-noodle seasonings are typically a much smaller mass fraction than the noodle and are also salt-, MSG-, and dehydrated-vegetable-rich, the composite mean obscures whether the lead, cadmium, and arsenic load originates in the wheat noodle, in the seasoning, or in both. The authors acknowledge this in the Discussion and recommend separate analysis in future work.
• Sample identifiers are anonymous letter codes (A–G) plus flavour descriptors; the paper does not name brands, so this source page does not need brand-firewall redaction.
• The Codex CXS 193-1995 comparators cited (Pb 0.2 mg/kg for cereal grain; Cd 0.2 mg/kg for wheat) are surrogate comparators chosen by the authors because Codex does not set a maximum for instant noodles specifically. Compliance interpretation depends on accepting cereal-grain/wheat comparators as applicable to a processed noodle-plus-seasoning composite, which the authors do not defend.
• The paper does not state the year of sample collection. Publication is August 2019 in the conference proceedings; the Summer Crash Course Programme 2018 framing suggests samples were collected in or before 2018, but this is inferred, not source-stated.
• No DOI is assigned; access via ResearchGate (publication ID 344782860) under a researcher-uploaded preprint convention.

Implications

• Certification (HMTc): Material input for Category 3 Row 3 (Pasta, wheat-based) instant-noodle sub-form on the Malaysian market for Pb, Cd, and total As. The Pb maxima (2.94 mg/kg) are substantially above the Codex cereal-grain comparator and above the Pb maxima reported in Canadian (Katyal et al. 2020), Iranian (Tajdar-oranj et al. 2018), and Nigerian (Onyema et al. 2014; Emumejaye et al. 2016) instant-noodle studies, suggesting market-specific elevation that the routing layer should not pool across markets without basis-comparability review.
• Courses: Useful for regulatory-divergence teaching — the same product (instant noodles) is non-compliant against Codex (all 7 samples) but compliant against the Malaysian national regulation (5 of 7 samples) for Pb, illustrating how national maximum levels can be substantially looser than international references.
• App: Adds Pb, Cd, and total-As data points for instant-noodles-dry / dry-seasoning-pack composite from the Malaysian retail market. Note: total-arsenic only, not inorganic-arsenic-specific; values are on a noodle-plus-seasoning homogenate basis, not separate noodle-only or seasoning-only values.
• Microbiome: Not addressed.

Wiki pages this source may touch

• lead
• cadmium
• arsenic-total
• noodles
• wheat
• pasta-wheat-based

Verification notes

• Publication: Malaysian Journal of Medicine and Health Sciences Vol. 15 Supp. 3 (Aug 2019), eISSN 2636-9346, pages 143–146. Conference-proceedings extended abstract, not a peer-reviewed full article; evidence tier B reflects this. ResearchGate DOI mint is the upload landing page, not a journal-assigned DOI; no_doi_assigned: true.
• Sample identifiers in the source paper are anonymous letter codes A–G with flavour descriptors (Curry, Tom Yam, Original Fried noodle, Chicken, Original seafood). These are flavour descriptors, not brand names; reproducing the source table is brand-firewall compliant.
• Speciation: arsenic is total only; the source reports “As” without inorganic/organic split and uses the value against a Codex cereal-grain comparator that itself does not speciate. Frontmatter uses tAs and the wiki-link list uses [[metals/arsenic-total]].
• Routing: instant noodles in the Malaysian market are wheat-based (paper explicitly states “Wheat flour is the main raw materials in making and processing of noodles”); routed to pasta-wheat-based only. No rice-based instant noodles in this sample, so rice-noodles is not declared. The earlier katyal2020-instant-noodles-canada-metals source declared both because it compared rice-based and wheat-based instant noodles directly.
• Matrices: instant-noodles-dry and dry-seasoning-pack retained for parity with katyal2020-instant-noodles-canada-metals. The composite homogenate caveat (noodles+seasoning measured together, not separately) is in Limitations.
• Sample-collection year is inferred (2018) from the “Proceedings of the Summer Crash Course Programme 2018” framing; not source-stated. sampling_year_range left as [2018, 2018] with this caveat in Limitations.
• No regulation slugs declared in ## Wiki pages this source may touch: the Codex comparator the authors used is CXS 193-1995 (matches regulations/codex-cxs-193-1995-tin-canned-foods only in number, not in substance — that wiki regulation page is the tin-in-canned-foods standard, not the general contaminants standard, so adding it would be wrong). The current contaminants standard the paper actually references is the 2015 General Standard for Contaminants and Toxins in Food and Feed (Codex Stan 193-1995, rev. 2015); no current wiki regulation page covers this generally. Surfaced for future regulation-page proposal but not declared as a wikilink here.
• Brand firewall: no brand names appear in the source paper. No redaction needed.

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.