Activation of Polyphenoloxidase in Pear Fruits by High Pressure Treatment.

During the course of study on the application of high pressure treatment to food science and technology,1-7) it has been observed that the color of fruits and vegetables including pears, apples, potatoes, and sweet potatoes rapidly darkens after high pressure treatment (see refs. 6 and 8). To investigate the cause of this unfavorable phenomenon in the high pressure processing of fruits and vegetables, effects of high pressure on polyphenoloxidase (6>r//zodiphenol: oxygen oxidoreductase, EC