Overview
Mattila and colleagues analysed the composition of commercial faba bean, lupin, buckwheat, quinoa, flaxseed, oil hemp and rapeseed press cake products sold in Finland. Cadmium was measured by ETAAS and copper, iron, manganese and zinc by ICP-OES, all on a dry-weight basis. Lead, arsenic and mercury were not measured.
Key numbers
- Cadmium (mg/100 g DW): flaxseed 0.0269 ± 0.0073, rapeseed press cake 0.0162 ± 0.0014, buckwheat bran 0.0152, faba bean whole 0.0016 ± 0.0005, oil hemp seed 0.0015 ± 0.0007 (Table 4, p. 113).
- Dehulling: buckwheat bran had about 3 times the cadmium of peeled buckwheat; whole faba bean about 3 times hulled and ground faba bean (Discussion, p. 114).
Methods (brief)
Milled samples digested in nitric acid in a block digestor; cadmium by ETAAS, other elements by ICP-OES in an EN ISO/IEC 17025 accredited laboratory. No detection limits or reference-material results printed.
Evidence Fitness
Accredited methods but very small sample numbers (n = 1 to 4 per product) and cadmium only among the toxic metals. It measures non-soy plant protein sources directly. For meal-replacement drinks and veggie burgers it is only an ingredient-level proxy. Table 4 gives n = 4 for whole faba bean where the Methods give n = 3.