Abstract
The validity of spectrophotometric procedure for the determination of the free energy of interaction between bovine plasma albumin and azo color (ponceau 3R), xanthene color (rose bengal, eosine and erythrosine) or triphenylmethane color (fast green and acid violet) was examined by the comparison with the established method of equilibrium dialysis. The free energies for the binding of these colors with bovine plasma albumin determined by spectrophotometric procedure were in the range of -6, 040 to -7, 460cal/mole at pH 5.2 and 7.0. These energy values by spectrophotometric procedure were somewhat lower than those calculated from dialysis equilibrium. However, the validity of the spectrophotometric method of measuring interaction with protein and food colors was proved.
