Enzymatic Browning
... Enzymatic browning is one of the most studied reactions in fruits, vegetables and seafood. ... This process is characterized by a darkening or browning affect due to this exposure to air. This browning is due the conversion of polyphenolic compounds, found in the fruit, to brown melanins and pigments. ... Black, oolong, and green tea are reliant on enzymatic browning for color and flavor development. ... On the other side of the coin there are also economic losses that occur because of the enzymatic browning affect. The enzymatic browning is the rate limiting factor in the expansion of the fruit and vegetable markets. There is no way to sustain the growth of this industry unless we can really get a handle on the browning. “Enzymatic browning is one of the most devastating reactions for many exotic fruits and vegetables, in particular tropical and subtropical varieties. It is estimated that over 50 percent losses in fruit occur as a result of enzymatic browning. ... ” If you follow the production of the fruit and vegetable industry down the line from planting, to harvesting, and finally to sales; by careful examination you see why the initial investment of time put into purchasing seeds, time to grow crops, and land to sustain these fruits could be so devastating since browning can only occur after all these moneys have been spent. Also it is clear why it is necessary to control the browning from beginning to the end. ... There are several enzymes involved in the browning reactions. “The first enzyme, monophenol monoxygenase or tyrosinase, initiates the browning reaction, which later involves diphenol oxidase or catechol oxidase and laccase. ... Monophenol oxidase activity is generally not a factor when examining plants since the hydroxylation reaction occurs at turtles pace compared to the oxidation reaction required for quinone production and initiation of the browning reaction. ... We can do this by examining scientific studies that apply the principles of enzymatic browning. I have selected two articles to see how enzymatic browning is applied in today’s research. The first article is titled “Relationship between the Enzymatic Browning and Phenylalanine Ammonia-lyase Activity of Cut Lettuce, and the Prevention of Browning by Inhibitors of Polyphenol Biosynthesis”.