A preliminary study on the spatial distribution of lead, cadmium, aluminium, and copper in different potato (Solanum tuberosum L.) varieties — implications for food safety and risk assessment

Food safety regarding heavy metal contamination is a critical global challenge due to the toxic nature of these elements and their ability to bioaccumulate in the food chain. This pilot study investigates the spatial distribution at different depths of potato tubers (Solanum tuberosum L.), of toxic elements such as lead and cadmium (both highly toxic) as well as aluminium (far less toxic compared to the previous two) and copper (micronutrient) to evaluate the efficacy of culinary processing in reducing toxic metal exposure. Three popular cultivars in southern Poland – “Soraya”, “Vineta”, and “Jelly” available on the Tarnów market were analyzed. Following the wet digestion step, the quantitative determination of selected metals was performed using Graphite–Furnace Atomic Absorption Spectrometry (Agilent 240Z AA). The accuracy of the analyses was validated using certified reference materials. The most interesting findings indicate that while mechanical peeling of tubers effectively minimizes exposure to Pb, it does not significantly reduce Cd levels. Analysis of behavior of aluminium revealed a distribution pattern similar to that observed for lead. Mechanical peeling led to a substantial reduction in the content of lead (69.0–82.0%) and aluminium (96.8–98.6%), as both elements strongly accumulated within the outermost periderm. Conversely, cadmium exhibited high mobility throughout the internal tissues, resulting in a minimal post-peeling concentration decrease ranging from 5.6% to 36.1%.