development
projects
Locations Peru Venezuela Dates March 2008 – June 2011 CABI project team Jayne Crozier Keith Holmes Perry Polar
investigating heavy metals in cocoa
Cocoa grows in pod-like fruits on tropical cacao trees. Although much of the worlds’ cocoa comes from Africa, it is also an important commodity crop in the Caribbean and Latin America.
so what’s the problem? Cadmium and other heavy metals are of great concern because they can be harmful to human health. Although humans can be exposed to heavy metals by inhaling particles in the atmosphere, the majority of heavy metals that occur in the body are consumed though contaminated food. The European Commission is responsible for setting maximum limits for contaminants in foodstuffs to protect consumers in Europe. They are currently considering implementing new legislation to impose more stringent limits on heavy metals in foodstuffs. The heavy metal cadmium has been found to be present in some chocolate and cocoa products. Heavy metals originate from both natural and man-made sources including: the formation of soil, the weathering of rock and volcanic activity, and industrial processes, mining, smelting, combustion of fossil fuels and the application of agricultural amendments. Anthropogenic activities (those undertaken by humans) have increased over recent decades and there is a tendency for the heavy metals produced to be more soluble in water and therefore easy for plants to take-up.
KNOWLEDGE FOR LIFE
what did this project do? Involving five partners, including the European Cocoa Association (ECA), Chocolate, Biscuits & Confectionery of Europe (CAOBISCO), country partners and CABI (who provided technical support and coordination), the project aimed to establish levels of cadmium and other heavy metals present in cocoa beans and soil where it grows and try to understand the factors which influence their uptake. Activities were divided into three phases: Phase 1 We reviewed and evaluated all of the available information on levels of heavy metals in cocoa, particularly cadmium, lead and aluminium and identified properties of soil which could influence the availability and uptake of heavy metals by plants. Phase 2 Samples of soil and cocoa beans were collected from the most important cocoa growing regions in both Peru and Venezuela. These were analyzed for the presence of aluminium, arsenic, cadmium, copper, iron, lead and zinc. Other soil properties which can affect the ability of plants to take-up heavy metals were also investigated. Phase 3 We provided a comprehensive report on our scientific findings, conclusions and recommendations, as well as standard methodologies for future monitoring and analysis of heavy metals.
results Generally, we found that the analyzed cocoa beans from both Peru and Venezuela contained low levels of cadmium. Some samples, however, did contain high levels. Levels of lead in cocoa from both countries were very low. We found that the pH of the soil was an important factor which affected the ability of plants to take-up heavy metals. Highlighting the complex nature of heavy metal uptake in cocoa, this study draws attention to the need for further research.
Partners Joint Project Managers: European Cocoa Association (ECA) and Chocolate, Biscuits & Confectionery of Europe (CAOBISCO) Instituto de Cultivos Tropicales, Perú Fundación Jardín Botánico de Mérida, Venezuela Sponsor Netherlands Ministry of Agriculture, Nature and Food Quality (LNV)
contact CABI, Bakeham Lane, Egham, Surrey, TW20 9TY, UK T: + 44 (0)1491 829080 E: cabieurope-uk@cabi.org www.cabi.org/uk
ID-HMCOCOA-02-13
Jayne Crozier, Project Manager