Study of bioaccessibility of cobalt species in berries and seeds by mass spectrometry techniques

Abstract

In recent years, açai berries (Euterpe Oleracea M.), goji berries (Lycium barbarum L.), bilberries (Vaccinium myrtillus L.), and chia seeds (Salvia hispanica L.) have increased interest worldwide due to their nutritional value and health benefits. In the present study, SEC-ICP-MS and μ-HPLC-ESI-MS/MS were used for the investigation of cobalt speciation and evaluation of its bioaccessibility in these products. Total cobalt content was determined, and açai berries (0.348 ± 0.042 μg g −1) and chia seeds (0.352 ± 0.036 μg g −1) were found as the best sources of this element. Different elution profiles of the extracts of examined berries and seeds obtained with the use of ammonium acetate, Tris-HCl, and SDS suggested that cobalt is bound by different bioligands in each biomatrix. The bioaccessibility of cobalt species was evaluated by SEC-ICP-MS. On the chromatograms of extracts obtained after simulation of gastrointestinal digestion, peaks corresponding to low molecular mass (17.00-1.35 kDa) cobalt complexes were observed. In the case of goji berries, their intensities were significantly higher on chromatograms of gastrointestinal than gastric extract. In enzymatic extracts, different forms of vitamin B 12 were identified by μ-HPLC-ESI-MS, including its natural forms-methylcobalamin (Me-Cbl) and adenosylcobalamin (Ado-Cbl).

In Vitro Assessment of the Physiologically Relevant Oral Bioaccessibility of Metallic Elements in Edible Herbs Using the Unified Bioaccessibility Protocol

“…The low pH and the presence of pepsin in the gastric fluid releases Co, which exhibits a high affinity for proteins and amino acids [ 35 ]. The high bioaccessibility of Co in the gastrointestinal phase may be ascribed to the formation of low-molecular-mass cobalt complexes [ 36 ] or the formation of chloride complexes (due to the presence of high concentrations of chloride salts), which exhibit high solubility in both gastric and gastrointestinal fluids [ 37 ]. Finally, the bioaccessibility of Ni in the gastric and gastrointestinal phases was similar to that reported in previous studies [ 19 ].…”

Atomic Spectrometry Update: review of advances in elemental speciation

“…The method was rapid: peak separation was within 2 min and the overall run including column re-equilibration took 4 min. The bioaccessible fraction of Co species, extracted from berries and seeds, was determined by SEC-ICP-MS. 120 Total Co determinations showed that acai berries and chia seeds (both with 0.35 ± 0.04 μg g −1 ) had higher concentrations than acai seeds or goji berries. Samples were extracted with simulated gastric and intestinal digestion (full details given) and the diluted extract injected into a Superdex 200 (10 × 300 mm, 10 μL) column (held at 24 °C) that was coupled to the cross-flow nebuliser of the ICP-MS instrument by PEEK tubing.…”