Ochratoxin A determination in swine muscle and liver from French conventional or organic farming production systems

Consumers generally considered organic products to be healthier and safer but data regarding the contamination of organic products are scarce. This study evaluated the impact of the farming system on the levels of ochratoxin A (OTA) in the tissues of French pigs (muscle and liver) reared following three different types of production (organic, Label Rouge and conventional). Because OTA is present at trace levels in animal products, a sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method using stable isotope dilution assay was developed and validated. OTA was detected or quantified (LOQ of 0.10 mu g kg(-1)) in 67% (n = 47) of the 70 pig liver samples analysed, with concentrations ranging from < 0.10 to 3.65 mu g kg(-1). The maximum concentration was found in a sample from organic production but there were no significant differences in the content of OTA between farming systems. OTA was above the LOQ in four out of 25 samples of the pork muscles. A good agreement was found between OTA levels in muscle and liver (liver concentration = 2.9 x OTA muscle concentration, r = 0.981).