Overview
The authors analyzed one commercial batch of farmed palm weevil larvae from Kumasi, Ghana, raw and after boiling, roasting and frying, for nutrients, metals and microbes. Lead (about 0.33 to 0.39 ppm) and cadmium (about 0.82 to 0.94 ppm) were quantified in every preparation, while mercury and arsenic were below detection limits that the authors note are too high to confirm compliance.
Key numbers
- Fresh larvae: lead 0.3342 ± 0.0028 ppm, cadmium 0.8296 ± 0.0003 ppm (Table 2).
- Roasted larvae: lead 0.3910 ± 0.0007 ppm, cadmium 0.9426 ± 0.0011 ppm; fried: lead 0.39045, cadmium 0.93115 ppm (Table 2).
- Mercury < 0.175 mg/kg and arsenic < 0.425 mg/kg in all samples (Table 2).
- Lead margin of exposure 1.79 to 1.96 and cadmium lifetime cancer risk 3.4 to 4.1 × 10^-6 (Table 3).
Methods (brief)
Microwave digestion with nitric acid and hydrogen peroxide; lead, cadmium, mercury and arsenic by ICP-MS, other minerals by flame AAS. DORM-4 fish protein reference material and blanks ran with each batch. Results are on a “sample basis” as analyzed; the paper does not say wet or dry weight.
Evidence Fitness
Direct data for farmed edible insects with a good method (ICP-MS, matrix-matched reference material), but the whole study is one farm batch with only analytical replicates, so it shows one farm’s level, not a population. The roasting and frying increases mostly track moisture loss. Mercury and arsenic non-detects have high detection limits.