Abstract
Ochratoxin A, B and citrinin were simultaneously determined in foods and food stuffs for over 20 years. Ochratoxin A was found in cereals such as wheat, barley, rye, coix seed, buckwheat and corn, and coffee bean, cacao, bean for bean-paste. Ochratoxin B was found in samples containing high level of ochratoxin A at the level of 1/3 to 1/10 of ochratoxin A. Co-occurrence of ochratoxin A and citrinin was frequently found in buckwheat and coix seed. It was not possible to confirm these toxins less than 1 μg/kg in samples because of the low sensitivity of the TLC method or HPLC analysis of ochratoxin esters until a few years ago. But now, it is possible to confirm these toxins less than 1 μg/kg with LC/MS/MS analysis. This revealed the contamination of these toxins at low level in food in Japan. Recently, Aspergillus carbonarius come to the fore as ochratoxin A-producing fungi, causing natural occurrence of ochratoxins in grapes in European counties. Four strains out of 6 strains examined produced ochratoxin A.
