Olive oil is the most important commodity in the Mediterranean region. It sustains the economies of Greece, Italy and Spain. Due to the production increase yearly and the demand of exportation to different countries, extreme quality control is necessary.
Many regulations for the MRLs (Maximum Residue Levels) in olives and olive oil, are applying by the European Union and the Codex Alimentarius of the Food and Agriculture Organization of the United Nations.
Phyto-sanitary products and herbicides are applied on the ground to eliminate problems and disease in olive orchards. These procedures result in the presence of residues from these products, in the olive derived foods. Studies have proved that residues of these products (insecticides and fungicides) can be found in olives and olive oil. The levels of these residues are bellow the set MRLs.
Herbicides are pesticides used to kill unwanted vegetation. They have health and environmental effects. These chemical tyrants can make the life of the weeds miserable and stop their growth.
Olive farmers use herbicides to remove weeds, so weeds won’t absorb the water, also to keep the ground clean around the olive tree for an easier harvest.
Herbicides applied on the ground, are concentrated in the top 10-15 cm of soil for a few months. Herbicides are washed into rivers and other water reservoirs, after heavy rains, resulting in the pollution of the waters.
During harvesting, if nets are not placed under the tree, the olive fruits come in contact with the herbicides still in the ground, with risks of incorporation into the olives and olive oil.
Gas Chromatography and Liquid Chromatography are two common methods available for the analysis of herbicides in olives and olive oil.