Chemical Residues

Veterinary drugs and feed additive residues in foods of animal origin

Ensuring that residues of permitted veterinary drugs and feed additives are at acceptable levels is important to ensuring safe food for the consumer. The Food Safety Department is involved in research focused on antiparasitic and antiprotozoal/anticoccidial drugs that are widely used in animal production. One aspect of the research is developing new methodologies for testing for these residues using biosensor technology for rapid screening and mass spectrometry for unequivocal confirmation of veterinary drug residues. A second aspect of the research is applying these technologies in residue monitoring, in surveys on the incidence of residues in foods (such as antiparasitic drugs in dairy products), and in studies at farm level designed to identify causes and remedial actions to prevent the occurrence of elevated levels of chemical residues in foods (such as anticoccidials in poultry products).

Investigation of benzimidazole and levamisole residues in food

New technologies are being developed in this project to detect benzimidazole and levamisole residues in food of animal origin. Screening methods will developed on ELISA and Biacore biosensor platforms for the detection of residues at abattoir and laboratory environments.

Investigation of anti-protozoan type drugs in food of animal origin

Diclazuril, halofuginone and toltrazuril are anti-protozoan drugs, which are used in the treatment and control of Eimeria infections in food producing animals. A number of research groups have attempted to develop technology to detect these substances but with lack of success due to difficulties in chromatographic separation or poor mass spectrometry response. Researchers at AFRC will develop screening assays to detect these substances in complex food matrices such as eggs, muscle and liver tissues using immunochemical based approaches. The technology developed on the project will provide a useful tool to monitor the safety of Irish food.

Novel Approach to Determine Untested Toxic Residues in Food

The objective of this research is to develop technology for the determination and confirmation of flukicide residues in food using mass spectrometry. The technology will be used to investigate the safety of food through application in persistence studies, retail surveys and statutory surveillance.

Research supporting the farmhouse cheese industry

The objective of this research is to study the chemical safety of farmhouse cheese products. Researchers at AFRC will develop technologies to determine the presence of macrocyclic lactone and benzimidazole residues in a range of farmhouse cheese products. The technology will be applied in a survey of the sector to verify the safety of farmhouse cheese products or identify any potential problems with chemical food safety, leading to corrective actions.

Detecting use of prohibited substances in meat production

Ensuring that foods of animal origin are produced without illicit use of prohibited substances is critically important to ensuring safe food for the consumer. The Food Safety Department has been involved in a broad range of research projects dealing with this issue, most recently in the areas of prohibited antimicrobials, nitrofurans, in meat and other foods, and of anabolic steroids, growth promoters, in beef production (see more..).

Profiling for abuse of anabolic agents in beef production

This safefood-funded project, conducted by Queen's University, Belfast and Ashtown Food Research Centre, Teagasc, is aimed at developing a monitoring scheme that will act as a significant disincentive to use of illegal growth promoting steroids in cattle production. Abuse of anabolic steroids, particularly administered as cocktails of drugs each at low concentration, is difficult to detect using conventional residue determination technologies. Biosensor technology will be used for biomarker profiling in blood to identify potential use of anabolic steroids and confirmation of use of natural steroids will be provided through analysis for steroid esters in animal hair by LC-MS/MS. At AFRC, a method has been developed for six anabolic steroids and this method will be applied, in combination with the biomarker profiling, to identify animals illegally treated with anabolic steroids. This combination of biosensor serum profiling of large numbers of cattle and confirmatory testing of hair samples for steroid esters from identified suspect animals is expected to provide a much more effective monitoring system for steroid abuse on the island of Ireland.

Natural toxins of fungal and algal origin in foods

Toxins produced naturally by fungi and algae may occur in foods of plant origin. Mycotoxins are some of the most important natural contaminants in food, many of them having carcinogenic and other toxic effects. Mycotoxins are produced by mycotoxigenic forms of fungi, on plant foods such as cereals, fruits, nuts during plant growth or during storage. The consumer may be exposed directly to mycotoxins from plant food products, or indirectly from animal foods, such as meat and dairy products, due to contamination of animal feed with mycotoxins. In the case of algae, microcystins may be produced by blue-green algae and may occur in algae products particularly those used in health foods.

Fusarium (zearalenone and trichothecenes) mycotoxins in cereal-based products

In the Food Safety Department, a project, funded by the Department of Agriculture and Food’s FIRM programme, has studied the occurrence of Fusarium (zearalenone and trichothecenes) mycotoxins in Irish cereals and products derived from cereals, such as flour-based products. This project involved development and validation of a range of chromatographic methods for these mycotoxins and surveys of the incidence of the mycotoxins in food products. The results of the studies demonstrated that residues of these mycotoxins may be found, above the specified maximum levels, in a small number of food products.

Investigation of the presence of toxic residues in Health Foods

This project will examine the occurrence of two types of natural toxins, Aristolochic acids and Microcystins (or blue-green algae toxins), in health food products in an all-island research initiative. The project will include the compilation of key data on toxins in health foods, the development of screening and quantitative testing capabilities, and surveys of retail products.

National Food Residue Database (NFRD)

The National Food Residue Database (NFRD) has been developed to collate all relevant data, of adequate quality, on residues of contaminants in food into a single web accessible database, available to scientists, the food industry, regulatory bodies and the general public. The NFRD serves as a source of data for use in establishing the status of food and may be used in risk assessment activities.

The NFRD is a public website that provides access to a database of scientific studies covering monitoring, surveillance and surveys of chemical contaminant residues in food. The residue data in the NFRD are obtained from a variety of sources including the national residue monitoring programmes (Department of Agriculture and Food, Marine Institute, Pesticide Control Service, Radiological Protection Institute of Ireland) and particular studies on chemical residues in food (Food Safety Authority of Ireland, Environmental Protection Agency, Teagasc).

Currently, the scope of the data covers veterinary drugs, prohibited substances, pesticides, heavy metals, dioxins and PCB’s, radionuclides, mycotoxins, and other contaminants such as nitrates and PAHs. The data comprise over 90 datasets and approximately 650,000 individual test results. The data in the NFRD has been published as annual reports – NFRD Report 2005 and NFRD Report 2006. The data in the NFRD are kept current through the addition of data from ongoing annual monitoring activities and studies on residues in food from a broad range of agencies. www.nfrd.teagasc.ie

In addition to the database, an extensive library of information on chemical residues, on regulations, on testing methods, and on norms and specifications has been incorporated into the website to assist the user's interpretation and exploitation of the data. The overall aim of the NFRD is to provide a user-friendly single source of information on chemical residues in foods that will assist in the production, manufacturing and sale of Irish food as well as supporting risk assessment and the development of food safety regulations. Currently (2006-2009) activities on exposure assessment and risk assessment on pesticides are being conducted in the context of the NFRD by partners at University College Dublin, the Pesticide Control Service and the Food Safety Authority of Ireland.