Abstract
Free radical signals were detected on the freeze-dried powder of the nondialysable and dialysable fractions of the melanoidins produced in the enzymatic browning systems of “apple enzyme·catechol” and “apple enzyme·catechol·methionine. ” Notwithstanding the dialysis of the browning systems, the coexistence of methionine in the systems and the reaction time of the enzyme, the g values were 2.004 in all specimens determined when the signal of DPPH had been comparatively determined as the standard of the value, or 2.007 in the case of Mn2+ as the standard.
The relative concentration of the radicals in the nondialysable fractions was dependent on the concentration of catechol and the enzymatic activity in the browning systems. The maximum of the relative concentration was observed at early stage of the reaction when the enzymatic activity was much higher.
The relationship between the antioxidative activity of the nondialysable fractions against linoleic acid and the relative concentration of the free radicals in them was suggested.
