Abstract
The brown apple juice was fractionated by means of gel filtration on a Sephadex G-200 column and two pigment peaks were obtained by estimating ODblue, OD280 and Folin reaction. The apple enzyme was incubated with a natural substrate (boiled apple extract), catechol, chlorogenic acid or pyrogallol as a model system of browning of apple and each reaction mixture was submitted to gel filtration for comparison. Similar to the brown apple juice, the model “Enzyme-Natural substrate” and “Enzyme-Catechol” systems gave two pigment peaks at about the same eluting position. On the other hand, in the case of the “Enzyme-Chlorogenic acid” system, only one peak was observed at the position between those of the two peaks of the model systems mentioned above, whereas three peaks were seen in the “Enzyme-Pyrogallol” system.
Then, absorption spectra of the pigments fractionated were determined. They were quite different from one another, even though the pigments had been isolated from the brown apple juice, the “Enzyme-Natural substrate” system and the “Enzyme-Catechol” system at the same positions of elution by gel filtration. In addition, characteristic spectrum was respectively estimated for the pigments of the systems of the “Enzyme-Chlorogenic acid” and “Enzyme-Pyrogallol. ”
