EFFECT OF KOJIC ACID ON THE OXIDATION OF O-DIHYDROXYPHENOLS BY MUSHROOM TYROSINASE

Kojic acid is a very effective inhibitor of mushroom tyrosinase as jud ged by its effect on the rate of pigmented products formation and on t he rare of oxygen uptake when different o-dihydroxyphenols are oxidize d by the enzyme. In addition to the ability of kojic acid to inhibit t he enzyme per se, the data show that kojic acid can change the spectru m of some pigmented products formed in its absence, probably due to th e ability of some o-quinones formed enzymatically to oxidize kojic aci d to a yellow product(s). These findings call for caution in the use o f kojic acid as an inhibitor of enzymatic browning in tissues and proc essed foods that are not yellow originally.