purification, characterization, and inhibition of tyrosinase from jerusalem artichoke (helianthus tuberosus l.) tuber

Background: because it tends to cause deterioration in the quality of food and appearance, food browning is unacceptable. tyrosinase, which catalyzes the transformation of mono phenolic compounds into oquinones, has been associated with this phenomenon. natural anti-browning agents were used to help avoid the enzymatic browning that occurs in many foods. methods: tyrosinase of jerusalem artichoke tubers was purified through (nh4)2so4 sedimentation, dialysis, chromatography, and finally gel electrophoresis. the purified enzyme was characterized and inhibited by rosemary extracts. results: purification of tyrosinase from jerusalem artichoke tuber were accomplished. the specific activity at the final step of purification increased to 14115.76 u/mg protein with purification fold 32.89 using cm-cellulose chromatography. the molecular mass was evaluated by electrophoresis and found to be 62 kda. maximum tyrosinase activity was found at 30 °c, ph 7.2, and higher affinity towards ltyrosine. inhibition percentage of heated extracts for leaves and flowers on tyrosinase activity was better than nonheated with 29.65% and 23.75%, respectively. the kinetic analysis exposed uncompetitive inhibition by leaves and flowers heated extracts. conclusions: in this study, we concluded the usage of natural anti-browning inhibitors like rosemary extract be able to be castoff to substitute the chemical agents which might be dangerous to social healthiness. natural anti-browning agents can be used to prevent the browning of many foods.