04.01.2013 Residues of Ochratoxin A in Roasted Coffee – Investigations from Year 2012 Report from a day in the lab Summary In the year 2012, 34 samples of roasted coffee (12 from organic production) were analyzed for the presence of Ochratoxin A at CVUA Stuttgart. None of the 34 samples that were analyzed for Ochratoxin A were found with an exceedance of the legal maximum resi- due limit (MRL) of 5 µg/kg. Among the organic samples of roasted coffee with posi- tive findings, the average amount of Ochratoxin A detect- ed was 1.1 µg/kg and the highest level was 3.2 µg/kg. For the conventionally produced samples with positive findings, the average amount of Ochratoxin A detected was 2.1 µg/kg and the highest level was 4.3 µg/kg. The assessment of the overall residue situation is therefore posi- tive. Background The mycotoxin Ochratoxin A (OTA) is a mycotoxin that is formed from various species of genus Penicillium und Aspergillus, which are found throughout the world in nature. In moderate climate zones the development of these toxins can occur when plant-based foods are stored under inadequate conditions, in contrast to the Aflatoxin species. OTA occurs almost exclusively in plant-based foods such as cereals, legumes, coffee, beer, wine grapes and their products (e.g. dried wine grapes, red grape juice, red wine), cocoa, nuts and spices around the world. OTA is seldom found in animal-based foods such as meat, milk and eggs. ADRESS Schaflandstraße 3/2 70736 Fellbach E-MAIL Poststelle@cvuas.bwl.de TELEFONE +49 711 3426 - 1234 INTERNET www.cvua-stuttgart.de +49 711 3426 - 1727 (Diagnostics) FAX +49 711 588176 +49 711 3426-1729 (Diagnostics) Seite 2 von 4 The long half-life of OTA in animal and human organisms is prob- lematic. After the consumption of contaminated products the pro- cess of eliminating the toxins from the body is very slow; this can lead to accumulation in kidney tissue. Ochratoxin A is highly toxic to the kidneys. The degree of damage depends on the dose and time of exposure. It is highly probable that, due to the formation of cell-damaging free radicals, this toxin could also be classified as genotoxic. Introduction The brown coffee beans that are familiar to us are the roasted seeds of the coffee cherry. The coffee plant grows into up to four meter high bushes, with white fragrant blossoms. Coffee plantations are mainly located in Latin America, Africa, and the region of India and Indonesia. The most economically significant types of coffee are the arabica and robusta. Arabica coffees are known for their aroma and make up the majority of coffee sales. Ro- busta coffee beans are, as the name implies, more robust, yielding higher quantities; although they are more sensitive to cold climates than arabicas, they are also more resistant to illness and pests. There are other, less often consumed coffees, the most well-known and expensive of which is perhaps the Kope Luwak which, thanks to a special cat species, has the unique aroma of intestines. These days it is hardly economical to grow coffee plants in their natural environment, in the shade of neighboring trees (Arabic is a shade plant). In contrast, coffee is overwhelmingly grown in large monocultures, whose fields have been cleared of vegetation. This has effects on the surrounding habitat and wildlife. The rate of pests and weed growth often increases, which must be stemmed by the use of pesticides. Negative effects also include a reduction in the diversity of species, the destruction of vegetation layers that pro- tect the soil, and soil erosion. In contrast, organic coffee plantations also host a variety of different trees, including fruit, spice, and other types of trees. The shade trees protect the coffee plants from too much sun and prevent the soil from drying out. The trees also provide nutrition and a habitat for insects, birds and other small animals. The workers on the plan- tations also benefit from the absence of pesticides; they aren’t ex- posed daily to the poison that is commonly used in conventional coffee cultivation and that can lead to serious health problems. [1,2] Seite 3 von 4 Near the equator the periods of blooming and harvest overlap, so the blossoms and berries can be found in different stages of ripe- ness on the very same coffee tree. A mechanical harvesting meth- od is not appropriate for such conditions, so the coffee berries are harvested labor-intensively by hand, which leads to a better quality of coffee. There are two possible methods of after-harvest treatment. One technique involves the mechanical removal of the pulp from the cof- fee berries in a fluid preparation, followed by a dissolution of the remaining pulp residues and enzymatic fermentation of the parch- ment layer surrounding the seed. The other method utilizes a dry preparation, by which the dried coffee berries are then peeled. The raw beans are finally sorted according to size, color and thick- ness, as a basis for determining the different levels of quality for roasting. [3, 4, 5]. Results Ochratoxin A in Roasted Coffee Samples Ochratoxin A No. Samp- No. Samples Average Highest les Analy- Containing Quantity Quantity zed Ochratoxin A > (from positive [µg/kg] BG* samples) [µg/kg] Organic pro- 12 5 (42%) 1.1 3.2 duction Conventional 22 7 (32%) 2.1 4.3 production * BG: designated limit of determination for Ochratoxin A: 0,4 µg/kg. The results show that 32% of the conventionally produced coffee samples contained Ochratoxin A; the average level among the posi- tive findings was 2.1 µg/kg. The highest detected level of 4.3 µg/kg was, however, lower than the legal limit of 5 µg/kg for roasted coffee . With a rate of 42%, more organic coffee beans were found with Ochratoxin A than conventionally produced beans. With an average level among the positive samples of 1.1 µg/kg and a high point of 3.3 µg/kg, the general picture for organically grown beans is gener- ally better than that of beans from convention production. Seite 4 von 4 Literature  http://www.rohkaffees.de (2010 Joerrens Impressum). http://www.fairtrade- deutsch- land.de/fileadmin/user_upload/materialien/download/download_stat ement_Kaffee.pdf.  Wikipedia.  http://www.hensler-kaffee.de/kaffeeanbau.html .  http://www.allvendo.de/kaffeewelt/kaffee_anbau.htm .  VO (EG) 1881/2006: Commission Regulation Nr. 1881/2006 from 19 December, 2006 for the determination of the maximum al- lowable content of specific contaminants in foods (ABl. L 364/5), last adjusted via the EU Regulation Nr. 594/2012 from 5 July, 2012 (ABl. L 176/43). Photo Credits: Coffee Bush, CVUA Stuttgart. Kaffeebohnen (Coffeebeans), Christian Lung, Pixelio.de, Image- ID=602011. Authors: Tamara Hummel, Renate Schnaufer.
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