Detoxification of Ochratoxin A on Heating under Acidic and Alkaline Conditions.

Ochratoxin A was heated under three different moisture conditions, and under acidic and alkaline conditions. Heating to 175°C under the dry conditions produced little change in the molecule and cytotoxicity, detected by TLC and in the effects on the proliferation of HeLa cells. When heated under the moist and watery conditions, a small change in molecule was found by TLC, but cytotoxicity was not reduced. Under the acidic conditions (0.1 N HCl) the decomposition of ochratoxin A was detected by TLC, however the change in cytotoxicity was not observed in this assay system. On the other hand, heating with NaOH (0.1 N) resulted in the decomposition and detoxification of ochratoxin A. The HPTLC analysis showed the formation of some decomposed compounds including L-phenylalanine. This indicates the hydrolysis of ochratoxin A is one of the decomposition reactions induced by alkali at high temperatures.