Dioxins and polychlorinated biphenyls contamination in poultry liver related to food safety – A review

Abstract

The present article reviews the most important scientific literature on dioxins and PCBs found in poultry liver and their relation with food safety and consumers' health. Dioxins and polychlorinated biphenyls (PCBs) are persistent organic pollutants with high chemical stability; they are lipophilic compounds and they are not destroyed by microbial, photochemical, chemical or thermal degradation. Dioxins and PCBs are ubiquitous environmental contaminants, which are present in all marine plant and animals, birds, mammals and humans and bioaccumulate through the food chain. In the last years, there has been concern regarding food contamination with different chemical substances and their effect on food safety. More particularly, at the end of the 20th and the beginning of the 21st century, there were a series of incidents related to dioxin and PCBs, which directly affected human or contaminated the soil and accumulated in feed and then in food products, such as poultry liver. It was shown in case of dioxin incident that tetra and penta-chlorinated congeners (the most toxic ones) accumulates selectively in poultry livers. Maximal concentrations have been fixed in the European legislation for dioxins and PCBs in food from animal origin, in order to protect the consumer. Data about background poultry liver contamination are scarce and the few available show levels below the legal limit for dioxins, but data are still lacking for DL-PCBs.

Introduction

The European Legislation together with the increasing consumer's demands require the slaughterhouses' owners and processors of poultry meat to provide high quality and hygienically safe products. Thus, careful monitoring should be imposed on all factors of the flow process, which could in any way affect the finished product, by applying the principle “from farm to fork”.

Meat inspection, and in particular edible offal inspection, including liver, is one step of that monitoring. Indeed, the liver, a major organ involved in metabolic processes, is considered to be one of the most eloquent witness of any disturbance in the body, as it is the subject to different types of etiologic attacks: infectious, toxic, metabolic, nutritional and traumatic (Doneley, 2004).

For food from animal origin, one of the possible cause of exclusion from consumption because of a risk for public health is the contamination with chemical substances, in particular dioxins, which are lipophilic contaminants tending to accumulate in fatty tissues, but also in liver, an organ rich in proteins able to bind these molecules.

Offal consumption is not negligible in European Union. When analyzing the data extracted from the “Comprehensive European Food Consumption Database; Concise Data Base summary statistics- Total Population”, it can be seen that the consumption of edible offal, including poultry liver, is between 1 g/day (in Ireland) and 26.1 g/day (in Poland), with an average of 7.12 g/day for the European Union, considering the countries that participated to the survey (European Food Safety Authority, 2011).

In particular, poultry liver consumption needs a special attention. Indeed, poultry liver is considered to be an important source of nutrients, such as vitamins, macro elements and microelements. In some countries, it is used in pregnant women diet and in nutritional disorders. Although studies in different countries were conducted regarding dioxins contents of different foods, very few reports which have been published refer to these contaminants level in offal and in particular in poultry liver (Baars et al., 2004, Fernandes et al., 2010, Hsu et al., 2007, Windal et al., 2010).

The aim of this review was to emphasize the possible contribution of poultry liver to dioxin human exposure through food chain.