Abstract
Decomposition of thiamine by Cu^<2+> under ordinary cooking conditions at the neutral range was investigated and it was found that the decomposition was affected by the initial concentration of thiamine, heating time and temperature, pH and kinds of buffers. The decomposition was accelerated especially by the presence of Cu^<2+> even at 0.02 ppm, as compared with other metal ions. Increase of TDS (thiamine disulfide) formation was accompanied with concentration of Cu^<2+>, pH, heating time and temperature. The main decomposition products of thiamine by Cu^<2+> at the neutral range were identified as OMP^<*1)>, Th^<*2)>, Thc^<*3)>, TDS^<*4)> and SB_1^<*5)> by means of paper chromatography. There was much more difference between the contents of TDS and Thc, when thiamine solution was heated with or without Cu^<2+>.
