Mineral and metal(loid)s content in canned tuna available in the Spanish market

Abstract

Global fish consumption has increased in recent decades, and tuna is among the most popular and widely consumed species worldwide, although demand varies by region. However, tuna, including canned tuna, may contain metal(loid)s such as Hg, As, and Cd, which can pose health risks if intake exceeds established safety limits and recommended intake. This study aimed to evaluate macroelements, microelements and metal(loid)s concentrations in all available private-label (store-brand: 58 types x 2 production batches) canned tuna products commercialized in the Spanish market at the time of purchase from supermarkets in the Vega Baja del Segura region (Alicante, Spain). All available canned tuna types were analyzed, and a novel aspect was correlating element content with FAO fishing area, tuna species, and covering liquid in recently purchased samples. As and Cd levels were highest in tuna from FAO areas 51 and 34, respectively. Significant differences by species were observed only for K, Fe, Cu and Cd. Tuna in brine generally had higher macro- and microelement levels, while tomato sauce samples showed the highest Cd content. The results suggest that the mineral and metal (loid) content in canned tuna is mainly influenced by the fishing zone and the covering liquid, while the species plays a less important role. In line with these results, which highlight the importance of origin and processing in the nutritional and toxicological characterization of canned tuna products. Our findings suggest that preservation techniques aimed at minimizing metal transfer during processing should be considered, particularly through the optimization of covering liquids, especially for products originating from areas where higher concentrations were detected.