The role of amylolytic and proteolytic enzyme activities of vegetables, fruits, and edible fungi in flavor enhancement during cooking

The enzyme activities of 25 vegetables, 5 fruits, and three edible fungi were analyzed in an attempt to understand the enzymatic generation of flavor components from food materials during cooking and processing. The enzymes of some vegetables and edible fungi were more active at pH 3 than at pH 5, whereas most exhibited lower starch-degrading activity at pH 3. Broccoli demonstrated high protease (15.17 U/g), carboxypeptidase (794.04 mU/g), and aminopeptidases (9.79 or 19.13 mU/g) activities at pH 3. The glutamyl aminopeptidase of spinach and enokitake was active in the acidic region, peaking at pH 4. There was no effect of 1% NaCl on most aminopeptidase activities at any pH, but they were significantly inhibited by 5% NaCl at pH 3. These results indicate that the vegetables, fruits, and edible fungi exhibited different enzyme activity depending on conditions such as pH and NaCl concentration.