The interest in artisanal chocolates has been growing, with an emphasis on bean-to-bar chocolates, due to few manufacturing processes, the preservation of cocoa butter, and a few ingredients used in the formulation (organic sugar, milk powder, dried fruits, or oilseeds) compared to the industrial scale production [1], [2]. In general, cocoa beans are ground under high temperatures in an electric stone grinder, known as melanger [1], [2]. In addition, bean-to-bar chocolates are produced with traceable cocoa beans, which provides a high-quality standard and valorization for small-scale producers. Brazil is one of the world's largest producers of cocoa, accounting for approximately 5% of its global production [3].

Although several compounds with health benefits have been reported for cocoa beans (e.g., antioxidants, flavonoids, minerals), recent studies have shown the presence of inorganic contaminants in this product and its raw material (cocoa beans) [4], [5], [6], [7]. Several studies have focused on Cd and Pb levels in cocoa beans and chocolates due to its association to adverse health effects, including cancer [8] and being consumed by children [9]. The mechanism for Cd and Pb accumulation in the cocoa fruit is currently limited. Blommaert et al. (2022) [10] recently studied the Cd translocation in a high Cd accumulating cultivar of Theobroma cacao L. and identified three major groups of ligands that bind Cd in cacao: O(C)-ligands (Cd-hydrated, Cd-cellulose, Cd-cell wall, Cd-Ca oxalate and Cd-organic acids), O(P)-ligands (R-PO4H2 ligands represented by Cd-phosphate and Cd-phytate) and S-ligands (Cd-phytochelatin, Cd-cysteine, Cd-glutathione and Cd-metallothionein). The authors also reported and 10–28-fold increase on Cd concentration in plant versus the topsoil and the following pattern of Cd levels in cocoa: placenta < nib < testa < pod husk < root < leaf < branch.

De Oliveira et al. [6] studied cocoa bean samples from Brazil, Ecuador, and West Africa reported levels higher than the threshold established by the Brazilian regulatory agency, ranging from <1.5–1590 µg/kg and <22–2530 µg/kg for Cd and Pb, respectively. Yannus et al. [7] also examined Cd and Pb in cocoa powder and cocoa bean samples of chocolate importers from Israel and reported values ranging from 125 and 103 ng/g and 72 and 40 µg/kg), respectively. Inorganic contaminants in conventional chocolate samples from Europe, the USA, and Israel were also studied by Yannus et al. [7], revealing values between 65 and 141 and 86–230 µg/kg for Cd and Pb, respectively. Villa et al. [5] investigated Cd and Pb in chocolates made with cocoa contents between 34% and 85% and reported similar concentrations, ranging from <1.7–0.108 and <21–0.138 µg/kg, respectively.

Even though bean-to-bar chocolates represent an expanding market, and it is largely consumed by children and adults, to the best of our knowledge, there is still a lack of studies concerning trace elements in this product. Thus, the main objective of this study was to evaluate the occurrence of trace elements arsenic, cadmium, cobalt, copper, mercury, lead, and selenium in samples from Brazil and Ecuador. Sampling considered the products available at the market (local and e-commerce) and bean-to-bar chocolates with different percentages of cocoa solids (white, milk, semisweet and dark chocolate). In addition, traceable cocoa beans from farms in the main producing regions of Brazil (Amazonas, Bahia, Pará, Espirito Santo) were also acquired to verify their trace element contents.