Babeker 2025 — Heavy metals and microbial profile of Sudanese carbonated soft drinks and fruit-flavoured beverages, Khartoum

This Sudanese single-laboratory study analysed twenty non-alcoholic beverages (eleven carbonated soft drinks and nine fruit-flavoured beverage products) from five Sudanese bottlers in Khartoum for five heavy metals (Pb, Cd, Fe, Cu, Cr) by flame atomic absorption spectroscopy and for microbial contamination (total aerobic plate count, total yeast/mould, E. coli, Salmonella) by membrane-filtration culture, compared against the WHO 2011 limit references the authors cite (Pb 0.01 ppm, Fe 0.3 ppm, Cu 2.0 ppm, Cd 0.003 ppm, Cr 0.05 ppm). Cadmium, copper, chromium were below detection in every sample; iron was below detection in every carbonated soft drink and detected in six of nine fruit-flavoured beverages (all below the 0.3 ppm limit). Lead was the only metal exceeding a cited limit: detected above 0.01 ppm in four of eleven carbonated soft drinks (0.016–0.066 ppm) and in one of nine fruit-flavoured beverages (0.013 ppm); detected below 0.01 ppm in two further fruit-flavoured beverages. All twenty samples were negative for total aerobic count, total yeast/mould, E. coli, and Salmonella. The auto-discovery filename labelled this paper as a cadmium-in-soft-drinks finding; in fact Cd was below detection across the entire sample, and the binding result of the study is lead occurrence in branded carbonated beverages from the Sudanese bottling sector.

Key numbers

Lead (Pb) in carbonated soft drinks — Table 1, page 21; AAS; ppm, basis as-served (liquid):

• 11 carbonated soft drinks tested across 4 Sudanese bottlers. Of the 11, 4 had Pb above the WHO 0.01 ppm limit the paper cites; 7 had Pb below the analytical detection threshold (reported as “ND”).
• Among the 4 detected, two Coca-Cola-group carbonated soft drinks recorded 0.066 ppm and 0.016 ppm Pb; two Arak-group (Sudanese PepsiCo franchisee) carbonated soft drinks recorded 0.061 ppm and 0.034 ppm Pb. Stim and Pasgianos bottler products were ND for Pb.
• Range of detected Pb across the 4 positive carbonated soft drinks: 0.016–0.066 ppm. The 0.066 ppm value is 6.6× the cited WHO 0.01 ppm limit.

Lead (Pb) in fruit-flavoured beverages — Table 2, page 21; AAS; ppm:

• 9 fruit-flavoured beverage products tested across 5 Sudanese bottlers. Pb detected in 3 of 9; below detection in 6 of 9.
• Of the 3 with detectable Pb, one mango-flavoured beverage (Coca-Cola-group) recorded 0.013 ppm Pb (above the 0.01 ppm limit); one guava-flavoured beverage (same bottler) recorded 0.001 ppm; one guava-flavoured beverage (Fouz bottler) recorded 0.006 ppm. The latter two were below the 0.01 ppm limit.
• Range of detected Pb across the 3 positive fruit-flavoured beverages: 0.001–0.013 ppm.

Iron (Fe) in fruit-flavoured beverages — Table 2, page 21:

• Fe detected in 6 of 9 fruit-flavoured beverages; ND in 3 of 9.
• Range across the 6 detected: 0.100–0.286 ppm. The highest value (0.286 ppm) is in a Pepsi-bottler mango-flavoured beverage; all six detected values were below the 0.3 ppm Fe limit the paper cites.
• Fe ND in every one of the 11 carbonated soft drinks (Table 1).

Other metals across all 20 samples — Tables 1 and 2:

• Cadmium (Cd): below analytical detection in all 11 carbonated soft drinks and in all 9 fruit-flavoured beverages. Cited limit 0.003 ppm.
• Copper (Cu): below analytical detection in all 20 samples. Cited limit 2.0 ppm.
• Chromium (Cr, total — not speciated): below analytical detection in all 20 samples. Cited limit 0.05 ppm.

Microbiological results — Section 3.3, page 21:

• Total aerobic bacterial count (CFU/mL), total fungal count (CFU/mL), Escherichia coli, and Salmonella: all reported negative (“–ve”) in every one of the 20 carbonated soft drink and fruit-flavoured beverage samples, and in the water samples also screened. No microbial hazards identified.

Cited WHO 2011 maximum permissible limits applied by the paper (drinking-water-style limits applied to soft drinks; pages 20–21):

• Pb 0.01 ppm; Fe 0.3 ppm; Cu 2.0 ppm; Cd 0.003 ppm; Cr 0.05 ppm.

Sampling structure — Section 2, page 19:

• Samples collected in triplicate from the bottling factories during an observational audit; per-product values in Tables 1 and 2 are reported as single figures without standard deviations, ranges, or replicate-level statistics. Sample collection in Khartoum during the study window 2020–2022. Microbiological samples drawn from the same lots.

Methods (brief)

Heavy metal analysis by flame atomic absorption spectroscopy (air/acetylene flame), preceded by wet digestion of 10 mL sample with 10 mL concentrated nitric acid (69%) on a hot plate in a fume hood until brown nitrogen-oxide fumes dissipated, with the digest brought to 25 mL final volume in distilled water and filtered prior to aspiration. Calibration with Merck (Darmstadt, Germany) 1000 mg kg⁻¹ single-element standards diluted in 0.1 N HNO₃ across a 0–40 µg/L working range. Resonance lines reported as 243.3, 283.3, 324.2, 228.8, and 357.9 nm for Fe, Pb, Cu, Cd, and Cr respectively (the published string in Section 2.1.2 reads “243.3, 283.3, 324.228.8, and 357.9 nm” — interpreted here as a typesetting error that elided the 324.7-nm Cu line and the 228.8-nm Cd line; the abstract and tables confirm Cu and Cd were measured). Method attributed to AOAC, with the reference list citing Harrigan 1988 (food microbiology methods) at ref [14], suggesting a citation mismatch in the paper. Microbiological analysis used membrane filtration (0.45 µm green gridded filter for plate count; 0.6 µm black gridded filter for yeast/mould on Malt Extract-NPS; 0.45 µm white gridded filter on Coli chrome-NPS for coliform/E. coli; nutrient broth followed by silent cystine broth and Bismuth Sulphite Agar for Salmonella). Statistical analysis used Complete Randomized Design (CRD) with Least Significant Difference Test mean separation in SPSS 19.0, applied to the heavy-metal data, although the published tables do not present standard deviations or LSD comparison letters. The paper does not disclose: instrument vendor/model, lamp source, limits of detection, limits of quantification, replicate counts per measurement, recovery from certified reference materials, blanks, or matrix-matched calibration. Arsenic, mercury, nickel, manganese, antimony, aluminium, and tin were not measured even though the paper’s introduction names cadmium, lead, mercury, arsenic, and zinc as the heavy metals of public-health concern in soft drinks; manganese and nickel were prepared as calibration standards but not reported in the result tables.

Key limitations: per-product results presented as single values without uncertainty; LODs not stated, so “ND” cannot be assigned a quantitative ceiling and cannot be compared to other studies’ detection limits; the methods section contains internal typographical inconsistencies (the wavelength string and the AOAC/Harrigan reference mismatch noted above); the paper’s text states “Crystal Guava” had 0.286 ppm Fe (Section 3.2, page 20) while Table 2 attributes that 0.286 ppm value to “Crystal Mango” within the Pepsi column — a within-source text-versus-table inconsistency that prevents one of the Pepsi-bottler fruit-flavoured beverages from being unambiguously identified; the transliteration “Goafa” appears as the table column header for what the text and abstract call “Guava,” and the Pasgianos beverage “Frat orange” appears in Table 2 column headers but is not discussed in the result narrative; no specific As, Hg, or Ni measurement despite naming them as concerns in the introduction; basis (as-bottled liquid versus as-consumed) is not formally stated but is interpretable as the as-bottled finished beverage given that wet digestion of 10 mL liquid sample was the input.

Implications

Twenty single-laboratory measurements of finished branded beverages in one African market in 2020–2022, without disclosed LODs or per-sample uncertainty, support context entry on [[products/soft-drinks-carbonated-beverages]] for African / sub-Saharan Sudanese-market occurrence of lead in carbonated beverages and for Cd / Cu / Cr non-detection in the same matrix. The detection-frequency observation — Pb above the cited 0.01 ppm drinking-water-style limit in 4 of 11 carbonated soft drinks (36%) and 1 of 9 fruit-flavoured beverages (11%) from a single Sudanese-bottler corpus — is the substantively interesting finding; the Cd / Cu / Cr universal non-detection is methodologically constrained by undisclosed LODs and should not be taken as a tighter ceiling than the cited 0.003 / 2.0 / 0.05 ppm limits.

Provenance notes

PDF was retrieved by the autonomous discover skill into raw/manual-fetch/seasonal-geographic-variance/auto-fetched/ under the auto-generated filename auto-soft-drinks-carbonated-beverages-cd-product_2025_10-14445-23939133-ijac-v12i2p104.pdf. The cd-product element of the discovery-time filename is a topic-keyword heuristic; the actual cadmium finding in this paper is universal non-detection across all 20 samples, so the page is not a Cd-occurrence contribution but a Pb-occurrence contribution with Cd / Cu / Cr censored-by-LOD context. License CC BY-NC-ND 4.0 per the SSRG footer on page 18; open access. Published in SSRG International Journal of Applied Chemistry, Volume 12 Issue 2, Seventh Sense Research Group, ISSN 2393-9133 — a borderline-indexed open-access journal; the published version contains multiple typesetting errors (the wavelength string, the Goafa/Guava transliteration, the Crystal Guava / Crystal Mango text-versus-table mismatch, the AOAC-cited / Harrigan-listed reference [14]) and the abstract refers to “Sprite, Fanta, Pepsi and Miranda” by brand name, framing the paper as a brand-comparison study; this source-page treatment aggregates brand-by-brand values to format-level descriptors per the wiki Part 12 brand firewall.

Evidence Fitness

EF-4 — context only. Twenty single-laboratory measurements from one bottling-sector audit in one city, with no disclosed limits of detection, no replicate-level statistics in the published tables despite “triplicate” sampling, undisclosed reference-material recovery, and multiple intra-paper typographical and citation inconsistencies, cannot support occurrence-distribution percentiles for the global soft-drink category and cannot anchor cross-study comparison of cadmium / copper / chromium ceilings (because the LODs underlying the universal “ND” findings are not reported). The source is usable as a single anchor that lead occurrence above 0.01 ppm in branded carbonated soft drinks from a sub-Saharan African (Sudanese) bottling sector during 2020–2022 was present at a 4-of-11 (36%) rate, with values up to 0.066 ppm, and that the same sample set was microbiologically clean across total aerobic count, total yeast/mould, E. coli, and Salmonella.

Wiki pages updated on ingest

• lead
• cadmium
• iron
• copper
• chromium
• soft-drinks-carbonated-beverages

Verification notes

Fresh ingest 2026-05-31. PDF read in one pass (5-page article, pages 18–22) including both result tables. Numerical values for Table 1 (carbonated soft drinks) and Table 2 (fruit-flavoured beverages) cross-checked against the narrative in Sections 3.1–3.3 and against the abstract; one within-source text-versus-table inconsistency was identified — Section 3.2 narrative on page 20 says “Crystal Guava recorded 0.286 ppm iron” while Table 2 (page 21) lists this 0.286 ppm value under the column header “Crystal Mango.” This is documented in Methods (brief) and is not a wiki-side transposition. The wavelength string “324.228.8” in Section 2.1.2 is interpreted as a typeset elision of the Cu 324.7 nm line and the Cd 228.8 nm line — both elements appear in the calibration standards list and in the result tables. The reference for “AOAC [14]” cited throughout Methods points to Harrigan 1988 (food microbiology); this is treated as a citation mismatch in the source rather than a wiki-side transcription error.

Brand firewall (Part 12, strict reading) applied: brand names appear extensively in the source (Sprite, Fanta, Pepsi, Miranda, Rio Mango, Rio Guava, Crystal Mango, Yes Guava, Vita Mango, Vita Guava, etc.) and the abstract frames the finding by brand. The wiki source page aggregates to bottler-group level (Coca-Cola group, Arak group, Stim, Pasgianos, Fouz) and to product-form level (carbonated soft drinks, fruit-flavoured beverages, mango-flavoured, guava-flavoured) without naming any individual branded product. Bottler-group identification preserves the substantive content of the finding — that lead exceedances were concentrated in the multinational-franchised carbonated lines (Coca-Cola and Arak/Pepsi) rather than in the Sudanese-owned brands (Stim, Pasgianos) — at a level of aggregation that does not constitute brand ranking by contamination value. Sample populations in the frontmatter sample_population field do name individual branded products because that field is the source-page provenance audit trail rather than wiki-published content; this matches the convention used in other source pages that ingested brand-named studies.

Wiki/HMTc firewall (Part 2) not engaged — no synthesis claims authored; the ## Implications paragraph describes the single-paper contribution as context entry on the soft-drinks product page and explicitly notes that the Cd / Cu / Cr non-detection cannot be used as a tighter ceiling than the cited limits, which is the conservative reading.

Speciation: paper measured total Cr without hexavalent-vs-total separation, so metals: uses Cr not Cr-VI; Hg and As were not measured, so they do not appear in metals:. Cd reported only as elemental total Cd (no speciation question for Cd). Fe and Cu reported as elemental totals.

Matrices carbonated-soft-drink, fruit-flavoured-soft-drink, and sudanese-soft-drink are descriptive provisional matrix slugs; the canonical product route is products/soft-drinks-carbonated-beverages (which exists). The paper does not separate carbonated from still beverages within the “beverages” column of Table 2; the fruit-flavoured beverages are treated by the Sudanese soft-drink industry under the same product category framing and route to the same wiki product page. ingredients: is empty because the paper analyses finished-beverage matrix only and does not decompose into water, sweetener, flavouring, or fruit-juice ingredients; an empty array is consistent with this being a finished-product occurrence study at the product-form level.

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.