Determination of cadmium concentrations in cocoa plantations (Theobroma cacao L.) in Costa Rica

Abstract

Cocoa cultivation is booming in Costa Rica; however, European authorities have established regulations for the importation of cocoa derivatives; which started in January 2019 with the fixation of maximum allowed concentration levels of cadmium. The objective of this study was to determine concentrations of cadmium in soil, root, leaf and non-fermented dry cocoa beans in two regions producing this crop in the country. The present exploratory study carried out in 2017 and 2018, determining the presence of cadmium in the root and leaf parts of the cacao tree, and in the grain. The information generated allowed finding that part of the cocoa production is located in an environment where the root and leaf organs can bioaccumulate this metal and transfer it to the cob where the concentrations of cadmium were detected in beans in a range of 0 to 8, 70 mg / kg. The percentage of positive samples in beans was higher in the South Region with 89.47%, while in the Northern it was 33.33%. However, in the analyzes of soils made in the samples from the same sites where the tree organs were sampled, only a very low percentage of positive samples were found in the Southern Region, three samples out of a total of 19, perhaps due the minimum detection limit for soil proposed by the laboratory was 1 mg / kg.