Abstract
A comprehensive multi-parameter safety and nutritional investigation was conducted on twenty-two commercial instant noodle samples, collected from retail markets and supermarkets in Dhaka, Bangladesh. Moisture (3.50 - 11.40%) and ash (1.71 - 7.06%) contents were determined as compositional and regulatory descriptors of the product matrix; one cup noodle returned a composite moisture value above the Codex maximum for fried instant noodle blocks (10%), although the analyzed portion included the seasoning and vegetable sachets and is therefore not directly comparable with that noodle-block specification. Soluble dietary fiber ranged from 4.80 to 13.93 g/100 g in fifteen samples. Sodium benzoate was detected in all fifteen analyzed samples at 8.96 - 24.36 μg/g, well below the Bangladesh Standards and Testing Institution (BSTI) limit of 150 mg/kg. Acrylamide was detected in sixteen of eighteen samples at 17.34 - 174.50 μg/kg by gas chromatography with electron capture detection (GC-ECD), the first such data for commercial noodles from Bangladesh. Thirteen potentially toxic trace elements were quantified by inductively coupled plasma mass spectrometry (ICP-MS) in twelve samples; lead (2.11 - 11.61 mg/kg) exceeded the Codex Alimentarius cereal limit (0.2 mg/kg) in all twelve samples and the BSTI limit (2 mg/kg) in nine. Inter-element correlation resolved two independent contamination signatures, a strongly co-varying Cr-Mn-Co-Ni-Cu-V group (r = 0.98 - 0.99) and a separate Pb-Zn-Cd group, indicating that lead enters by a route independent of the flour and equipment-derived elements. Dietary risk assessment using the USEPA framework showed the non-carcinogenic Hazard Index (HI) ranged from 2.86 to 10.10 for adults, exceeding unity in every sample, with arsenic and lead dominant; non-essential elements alone accounted for 52.7 - 87.9% of HI and exceeded unity without any contribution from essential elements. A consumer-group sensitivity analysis raised HI to 6.86 - 24.25 for school-age children and 13.72 - 48.50 for high-consuming children. Arsenic was determined as total arsenic and was not speciated, so carcinogenic risk was estimated as a conservative screening scenario in which the whole of the measured total arsenic is assumed to be inorganic arsenic. On that assumption, carcinogenic risk from dietary arsenic (2.52 × 10−4 - 5.32 × 10−4 for adults) exceeded the USEPA upper bound (10−4) in all samples, and life-stage-integrated lifetime risk reached 1.60 × 10−3. These findings indicate widespread potentially toxic trace element contamination posing a significant non-carcinogenic risk to regular consumers and, conditional on the inorganic-arsenic screening assumption stated above, a carcinogenic risk that arsenic speciation would be required to confirm, and they call for urgent regulatory enforcement and mandatory pre-market quality control.