Overview
Okeke and Sanda measured chromium, lead, and total arsenic in banana, pineapple, and orange after natural ripening and after laboratory calcium-carbide ripening. All measured values were below the paper’s cited FAO limits, but the calcium-carbide-ripened fruits had higher chromium (Cr), lead (Pb), and arsenic (As) than their naturally ripened counterparts.
Key numbers
Table 1 reports fruit metal concentrations in mg/kg. The paper labels the arsenic column as As and uses total digestion/AAS rather than arsenic speciation, so these values are treated as total arsenic.
| Fruit and ripening condition | Cr (mg/kg) | Pb (mg/kg) | tAs (mg/kg) |
|---|---|---|---|
| Banana, naturally ripened | 0.001 +/- 0.01 | 0.001 +/- 0.01 | 0.001 +/- 0.01 |
| Pineapple, naturally ripened | 0.002 +/- 0.01 | 0.001 +/- 0.01 | 0.002 +/- 0.01 |
| Orange, naturally ripened | 0.009 +/- 0.03 | 0.001 +/- 0.02 | 0.003 +/- 0.01 |
| Banana, calcium-carbide ripened | 0.003 +/- 0.01 | 0.004 +/- 0.01 | 0.003 +/- 0.01 |
| Pineapple, calcium-carbide ripened | 0.006 +/- 0.03 | 0.003 +/- 0.01 | 0.004 +/- 0.01 |
| Orange, calcium-carbide ripened | 0.014 +/- 0.06 | 0.002 +/- 0.01 | 0.006 +/- 0.03 |
The authors cite FAO limits of 0.5 mg/kg for Cr, 0.2 mg/kg for Pb, and 0.5 mg/kg for As. The highest reported values in this study were 0.014 mg/kg Cr in artificially ripened orange, 0.004 mg/kg Pb in artificially ripened banana, and 0.006 mg/kg total arsenic (tAs) in artificially ripened orange.
For artificially ripened fruits, adult estimated daily intake values were reported as 2.2E-5 to 0.0001, depending on fruit and metal. Child EDI values were higher, ranging from 2.5E-5 to 0.0002. Hazard index values were below 1 for every fruit: adults 0.0115 for banana, 0.0111 for pineapple, and 0.0123 for orange; children 0.0200 for banana, 0.0191 for pineapple, and 0.0213 for orange.
Methods (brief)
Freshly unripe but mature pineapple, banana, and orange were purchased from three local markets in Bauchi Metropolis with assistance from fruit vendors. Fruits were divided into naturally ripened and artificially ripened groups; the artificial group was ripened with 10 g calcium carbide. Ripened fruit was washed with deionized water, peeled, sliced with a plastic knife, oven-dried at 70 degrees C for 48 h, ground, sieved, and stored in airtight plastic containers. One gram of each pulverized fruit sample was ashed at 550 degrees C for 6 h, dissolved in 10% HNO3, heated for 20 min, filtered, and analyzed in triplicate by atomic absorption spectrophotometry.
Related evidence
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