L-Phenylalanine Ammonia-lyase Activities in Japanese Chestnut, Strawberry Apple Fruit, and Bracken

Abstract

L-Phenylalanine ammonia-lyase (PAL) activities in Japanese chestnut, strawberry, apple fruit, and bracken were assayed by using the crude enzyme solutions extracted from their acetone powders with 0.05M sodium borate buffer, pH 8.0 or 8.8. PAL activity could not be detected in the freshly sliced tissue of Japanese chestnut, but occurred remarkably in the tissue within 36 hours after slicing and the activity was maintained constantly up to 72 hours. A significantly high activity of PAL was observed in strawberry at reddish ripe stage, though only a slight activity was detected at greenish stage. In apple the activity of PAL was observed in only the reddish parts of peel. From the results in strawberry and apple, it could be considered that PAL is closely related to the formation of anthocyanins in fruits. The stem of bracken showed the prominently high level of PAL activity. The activities in the top and basal portions of the stem were higher than that in the middle.