The increasing shift from meat- to plant-based diets has necessitated a deeper understanding of the presence of heavy metals and their speciation in plant-based foods. Cadmium, a toxic heavy metal, can pose significant health risks. Significant research gaps persist in the field of cadmium speciation, particularly with respect to its bioavailability and the fact that many compounds binding cadmium remain unidentified in plant-based foods.

This research presents a methodology that integrates SEC-ICP-MS/MS and SEC-QTOF-MS for the identification of Cd-binding compounds, along with simultaneous speciation analysis of multiple elements, including sulphur, phosphorus, zinc, iron, and calcium in plant-based foods. Sulphur and phosphorus serve as markers for proteins and peptides, while zinc, iron, and calcium influence cadmium bioavailability.

Multielemental speciation and identification of proteins, peptides, and small molecules was conducted on various plant-based foods, including tiger nuts, beetroot leaves, black-eyed beans, and lentils. Additionally, a comparative analysis was performed to identify differences between these samples. The study found distinct cadmium binding patterns among the different foods. Future work will focus on correlating binding patterns of cadmium with its bioaccessibility in an in vitro digestion model.