The name of this mycotoxin comes from Penicillium citrinum, the organism from which it was firstly isolated in 1931.3 Citrinin is produced by several strains of Penicillium and Aspergillus, reason for which it often occurs with Ochratoxin A.3, 4 Other citrinin producing Penicillium spp. are P. lividum, P. implicatum, P. citreoviride, P. viridicatum and others.3, 7 Some Monascus strains are known to produce citrinin as well.5 Chemically, citrinin is a phenolic derivate compound and presents a bright yellow color on chromatograms viewed under visible light.4 This mycotoxin is insoluble in water and it dissolves in ethanol, benzene, acetone and chloroform.1, 6
Originally, citrinin was characterized as an antibacterial antibiotic.3, 4 As well as being able to inhibit growth of several bacterial species (mainly Gram-positive e.g. Bacillus subtilis and several Micrococcus strains), protozoa, filamentous fungi and yeasts are also known to be affected.1, 5, 6
Toxic effects were extensively studied on model animals like mice, swine and poultry, with the kidney identified as being the main target organ.1, 3, 4, 6, 7 These effects include enlargement and degeneration of proximal tubules.5 In addition, citrinin exerts a depressive action on the central nervous system.1, 3, 5 Dietary exposure to citrinin has been reported to impair liver metabolism, increase water consumption, provoke diarrhea and alter intestinal villar morphology (the last is a poultry specific problem).1, 3, 4, 6, 7 Furthermore, citrinin has teratogenic and carcinogenic proprieties.3, 5
In the EU, there is a regulation concerning the maximum allowed presence of citrinin in food supplements that are based on rice fermented with red yeast Monascus purpureus set at 2000 ppb.2 No regulation is currently set for the presence of this mycotoxin in feed. In the US, no regulation exists in food or feed materials.