The first attempts to commercialize Fairtrade goods in Northern markets were initiated in the 1940s and 1950s by religious groups and various politically, the primary cooperative and its member farmers must operate to certain political standards, imposed from Europe. A part for fair marketing issues, another problem of “colonial goods” as cocoa can be represented by the difficult traceability. In fact, these row food materials are often constituted by harvests of many different small producers, sometime even of different geographical origin. A different geographical origin also often means (for cocoa as for coffee and spices) differences in flavour and quality. For example for cocoa, and derived products such as chocolate, there are estimators able to distinguish and prefer a certain Country of origin (e.g. Ivory Coast, Ghana, Congo, Indonesia, Malaysia, India, Brazil, Ecuador, Dominican Republic, etc.) compared to others. For these reasons the traceability and authenticity of origin of cocoa can become a commercial very valuable characteristic. 
There are fairly new analytical techniques able to answer this raising necessity, for example isotopic analysis, or more precisely, Stable Isotope Ratio Analysis (SIRA). This approach is based on the fact that most chemical elements have a certain percentage of stable natural isotopes, meaning atoms with different number of neutrons inside their nucleus (and therefore different atomic mass) compared to “regular” atoms of that certain chemical element. E.g. “regular” carbon (C) has mass number 12 (12C) and its abundance is nearly 99%, then there are natural traces of carbon atoms with mass number 13 (13C) and mass number 14 (14C). Also hydrogen, nitrogen, oxygen and many other elements have stable natural isotopes. The interesting fact is that the ratio between isotopes of the same element is slightly different depending on many factors, among which geographical origin of a certain material or food. This is the reason why SIRA has many important applications such as determining origin of water, rocks or organic matter. Many are the applications in the food sciences: distinguishing natural from artificial flavours; acetic acid obtained by fermentation from that obtained by industrial processes; wild from farmed fish; added sugar in wine; watered milk or wine; wine, oil or raw food materials fraudulently declared as monovarietal; cheese, sugar, spices and other foods fraudulently declared from a certain geographical Region; etc. Behind the natural phenomenon of relative isotope abundance there is the “fractionation process”: in fact, different isotopes of the same element behave chemically and physically in a slightly different way, due to their different atomic mass. For example water in atmospheric vapour, rain and snow is “lighter” because heavy isotopes of hydrogen and oxygen composing the H2O molecules are more difficult to evaporate, therefore tend to remain in sea and ocean waters. Also plant metabolism tends to fractionate isotopes: water absorption from soil and transpiration is characteristic of every species and depends on temperature, altitude and latitude, but in general plants tend to accumulate heavier isotopes of hydrogen, oxygen, nitrogen and carbon. In order to discriminate very small differences in the isotopic ratio, instruments providing high sensitivity, precision and accuracy are necessary, such as mass spectrometry (MS) or nuclear magnetic resonance (NMR). With these instruments it is possible to accurately discriminate e.g. cocoa produced in different Countries, as shown in figure 1. Another approach for food traceability is the analytical research of rare elements, usually present in concentrations below 0.1%, as lead (Pb), strontium (Sr) and rubidium (Rb). Their abundance and isotopic ratio is strictly related to soil characteristics and therefore to geographical origin fingerprinting. These analysis are usually performed in mass spectrometry (MS).
Figure 1: Assessing Country of origin (Ghana, Ivory Coast or India) with carbon stable isotope ratio analysis. Modified from Picarro Inc (2)
Bibliography
1)Definition developed by FINE, an informal association of four international fair trade networks: Fairtrade Labelling Organizations International, World Fair Trade Organization (WFTO), Network of European Worldshops and European Fair Trade Association (EFTA)
2)Origin and Adulteration in the Supply Chain – presentation from Picarro Inc., October 27th, 2011
