Concentrations and bioavailability of cadmium and lead in cocoa powder and related products

Abstract

Concentrations and bioavailability of cadmium (Cd) and lead (Pb) were determined in cocoa powders and related products (beans, liquor, butter) of different geographical origins. Particular attention was paid to the fractionation of these metals, which was investigated by determining the metal fraction soluble in extractant solutions acting selectively with regard to the different classes of ligands. The targeted classes of Cd and Pb species included: water-soluble compounds, polypeptide and polysaccharide complexes, and compounds soluble in simulated gastrointestinal conditions. The bioavailability of Cd and Pb from cocoa powder, liquor and butter was evaluated using a sequential enzymolysis approach. The data obtained as a function of the geographical origin of the samples indicated strong differences not only in terms of the total Cd and Pb concentrations, but also with regard to the bioavailability of these metals. The Cd concentrations in the cocoa powders varied from 94 to 1833 microg kg(-1), of which 10-50% was potentially bioavailable. The bioavailability of Pb was generally below 10% and the concentrations measured in the cocoa powders were in the 11-769 microg kg(-1) range. Virtually all the Cd and most of Pb were found in the cocoa powder after the pressing of the liquor.

Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador

“…However, concentrations of heavy metals (including Cd and Pb) above a critical level (0.6 mg kg −1 for Cd), established by European Union, has raised concerns of safety in the consumption of cacao-based chocolate (dark chocolate) (Mounicou et al, 2003;Zarcinas et al, 2004;Dahiya et al, 2005). For instance, cacao-based chocolate contained 3.4 times more Cd than milk-based chocolate (Dahiya et al, 2005).…”

“…Guayas and El Oro provinces are characterized for agricultural as well as mining activities, particularly artisanal gold mining, which has contributed to heavy metal contamination in rivers (Bech et al, 1997;Mounicou et al, 2003;Ramirez Requelme et al, 2003). In a recent study, the concentration of heavy metals in sediment and water of three rivers in southern Ecuador were monitored, and two of the three rivers were reported to have Cd concentrations higher than USEPA maximum contaminant level (MCL), whereas sediments from one river contained Cd levels above Environmental Canada Probable Effect (Carling et al, 2013).…”

Morphological, biochemical, molecular and ultrastructural changes induced by Cd toxicity in seedlings of Theobroma cacao L.

“…This species is chiefly exploited for the production of chocolate; but it can also be used in cosmetics, beverages, jellies, creams and juices (Almeida and Valle, 2007). Cd concentrations were observed in cocoa powders and related products (beans, liquor, butter) of different geographical origins (Mounicou et al, 2003).…”

Relationships between Cadmium in Tissues of Cacao Trees and Soils in Plantations of Trinidad and Tobago

“…Also of great public significance are the levels of Cd in cocoa beans, cocoa powders and cocoa liquors used for chocolate production [1] [16]- [19]. The Cd content in chocolates is a function of the cocoa bean nib content and diminishes in the order: bitter chocolate (used for baking), dark chocolate (bittersweet and semi-sweet), milk chocolate and white chocolate [18]. It is thus not surprising that food safety concerns have been generated over the presence and levels of Cd in cocoa, as many consume these products daily.…”