Sofyan 2023 — Microbial and metal contamination of banana-based steamed sponge cake (bolu kukus pisang ambon), Yogyakarta

This single-author Indonesian Diploma III pharmacy programme study formulated three banana-based steamed sponge cakes (bolu kukus pisang ambon) intended as an alternative snack for hypertensive patients, varying only the pisang ambon (Musa acuminata Colla) to wheat-flour mass ratio (1:1, 2:1, 3:1), and tested each formulation once for microbial contamination (total plate count, yeast and mould count, Escherichia coli) and metal contamination (Pb, Cu, Zn, total As) against Indonesian SNI 01-3840-1995 bread-product limits and SNI 7387:2009 Pb/As limits. All three formulations met every reported standard: Pb 0.1036–0.1207 mg/kg (limit 1 mg/kg), Cu 0.2897–0.3243 mg/kg (limit 10 mg/kg), Zn 1.6005–4.6056 mg/kg (limit 40 mg/kg), As below detection in all three (limit 0.5 mg/kg), aerobic plate count 1,566.66–8,800 cfu/g (limit 1×10⁶ cfu/g), yeast/mould <10 cfu/g in all three (limit 1×10⁴ cfu/g), E. coli negative in all three. Single-sample-per-formula design and a research-prepared rather than retail product limit the source to context-only evidence for any commercial banana sponge cake or Indonesian baked-goods occurrence question.

Key numbers

Metal contamination (Table 3, page 29; AAS / Spektrofotometri Serapan Atom; mg/kg, basis not stated explicitly — interpretable as as-baked steamed cake):

• Pb (timbal): F1 0.1207 mg/kg; F2 0.1036 mg/kg; F3 0.1118 mg/kg.
• Cu (tembaga): F1 0.3243 mg/kg; F2 0.3059 mg/kg; F3 0.2897 mg/kg.
• Zn (seng): F1 1.6005 mg/kg; F2 4.6056 mg/kg; F3 3.6758 mg/kg.
• As (arsen, reported as total elemental As): “Negatif” — below detection — in all three formulations. The paper does not state the AAS limit of detection for As.

Microbial contamination (Table 2, page 27; sample size 250 g per formula):

• Yeast/mould count (AKK): <10 cfu/g in all three formulations.
• Aerobic plate count (ALT): F1 2,333.33 cfu/g; F2 8,800 cfu/g; F3 1,566.66 cfu/g.
• Escherichia coli: negative in all three formulations.

Statistical comparison across the three formulations (Table 4, page 30; SPSS 23, 95% confidence; the paper reports “Nilai asymp sig” which is the Kruskal-Wallis asymptotic significance):

• ALT: p = 0.000 (significant differences across formulas).
• AKK: p = 0.025 (significant).
• Pb: p = 0.558 (not significant — the three formulas did not differ for Pb).
• Cu: p = 0.076 (not significant at α = 0.05).
• Zn: p = 0.048 (significant).

Reference standards cited by the paper:

• SNI 01-3840-1995 (Roti / bread quality standard, Badan Standardisasi Nasional 1995): Pb max 1 mg/kg, Cu max 10 mg/kg, Zn max 40 mg/kg, As max 0.5 mg/kg; ALT max 1×10⁶ cfu/g; AKK max 1×10⁴ cfu/g; E. coli must be absent or <3 APM/g.
• SNI 7387:2009 cited as the operative Pb and As limit standard.

Formula composition (Table 1, page 25):

• F1: pisang ambon 200 g + wheat flour 200 g + baking soda qs + 2 eggs + honey 5 g + palm sugar 2 g. Banana : flour = 1:1.
• F2: pisang ambon 200 g + wheat flour 100 g + baking soda qs + 2 eggs + honey 5 g + palm sugar 2 g. Banana : flour = 2:1.
• F3: pisang ambon 300 g + wheat flour 100 g + baking soda qs + 2 eggs + honey 5 g + palm sugar 2 g. Banana : flour = 3:1.

The paper describes the flour as “tepung terigu bebas gluten” (literally “gluten-free wheat flour”); this self-contradictory description is reproduced from the source. Wet ingredients used the egg whites (putih telur) whipped to peak; cakes were steamed for 20–30 minutes in a sealed pot.

Methods (brief)

Metal contamination measured by atomic absorption spectrophotometry (AAS / Spektrofotometri Serapan Atom / SSA) at the Balai Laboratorium Kesehatan dan Kalibrasi, Dinas Kesehatan Daerah Istimewa Yogyakarta. Pb and As compared to SNI 7387:2009; Cu and Zn compared to SNI 01-3840-1995. The paper does not report instrument vendor or model, digestion method, calibration range, replicate counts per measurement, limits of detection, limits of quantification, or recovery from reference materials. As speciation not reported; AAS without hydride generation or sample-specific chemistry is consistent with total elemental arsenic (tAs), not inorganic As. Microbial methods: AKK (yeast/mould) on PDA at room temperature for 24 h; ALT (aerobic plate count) on NA at 37°C for 24 h; E. coli on LB with Durham tubes and confirmation on EMBA at 37°C for 24 h, against SNI 01-3840-1995. Statistical analysis used SPSS 23 with Shapiro-Wilk for normality; ANOVA was the planned test but the paper’s Table 4 reports “Nilai asymp sig,” indicating Kruskal-Wallis was the test actually used (consistent with the small per-cell n).

Key limitations: each formula was tested as a single composite sample (no analytical replicate counts disclosed), so per-formula variability cannot be assessed; the metal-test sample mass is not stated and may differ from the 250 g microbial sample; basis (as-baked, dry weight, or as-served) for the mg/kg metal results is not explicitly specified; LODs are not reported, so the “Negatif” arsenic finding cannot be assigned a quantitative ceiling; instrument validation parameters (calibration, recovery, blanks, certified reference materials) are absent.

Evidence Fitness

EF-4 — context only. Three laboratory-prepared formulations of a research-developed snack, each tested once, without disclosed analytical replicates, LODs, or reference-material recovery, cannot support occurrence-distribution percentiles, ingredient-attribution synthesis, or comparison against another study’s banana-cake or banana-containing-baked-good values. The source is usable as a single anchor point that a research-prepared banana-flour steamed cake in Yogyakarta in 2023 reported Pb on the order of 0.10–0.12 mg/kg and total As below detection by AAS, and as a pointer to the SNI 01-3840-1995 and SNI 7387:2009 Indonesian limits the paper cites.

Implications

Not synthesised — single-paper source page.

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-fruit-snacks-tas-product_2023_10-33088-jp-v2i1-365.pdf. The “fruit-snacks” portion of that auto-handle is a discovery-time heuristic; the actual matrix is a steamed banana sponge cake (bolu kukus), classified by the paper itself under the Indonesian SNI 01-3840-1995 bread/baked-goods standard, so the page routes to products/bread-and-baked-goods rather than products/fruit-snacks. License CC BY-NC-SA 4.0 per Jurnal Pharmacopoeia footer; open access.

The paper title as printed on page 23 reads “Musa acuminta Colla” (typographic error in the source); the body text and methods consistently use the correct binomial “Musa acuminata Colla.” The frontmatter title preserves the printed typo per Cochrane-bar verbatim-title convention.

Wiki pages updated on ingest

• lead
• arsenic
• copper
• zinc
• banana
• wheat
• honey
• eggs
• bread-and-baked-goods

Verification notes

Fresh ingest 2026-05-31. PDF read in two passes (pages 1–6 and 7–11) for the 11-page article. Numerical values for Table 2 (microbial), Table 3 (metals), and Table 4 (statistics) cross-checked against both the abstract numbers (page 23) and the discussion text (pages 27–30); no internal contradictions found. Speciation flagged as tAs per AAS-without-hydride-generation convention; the paper itself only writes “arsen (As).” Brand firewall (Part 12) not engaged — no commercial brand names appear in the source. Wiki/HMTc firewall (Part 2) not engaged — no synthesis or HMTc-threshold claims authored. Provisional matrices slugs banana-steamed-sponge-cake and prepared-snack are descriptive rather than canonical taxonomy entries; product routing is to the existing bread-and-baked-goods slug per the SNI 01-3840-1995 classification cited by the paper. Palm sugar listed in the formula but not added to the ingredients: array — single research-formulation use does not warrant routing fan-out to a sugar-form ingredient page that does not yet exist.

Audit subagent 2026-05-31 returned PROMOTE; flagged that the metals: frontmatter array carried Cu and Zn but the “Wiki pages updated on ingest” list omitted [[metals/copper]] and [[metals/zinc]] — applied (both metal pages exist; frontmatter ↔ wiki-pages-list consistency restored). Audit also flagged the provisional matrices slugs already documented in the paragraph above as borderline; left as-is per protocol (descriptive matrices flagged in verification notes are acceptable when the canonical taxonomy lacks a tight fit and the product-route is correct).

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.