EFFECT OF CARBON-DIOXIDE ON THE INACTIVATION OF FLORIDA SPINY LOBSTERPOLYPHENOL OXIDASE

Florida spiny lobster (Panulirus argus) polyphenol oxidase (PPO) expos ed to CO2 (1 atm) at 33, 38, and 43-degrees-C showed a decrease in enz yme activity with increased heating time. Enzyme inactivation by CO2 w as faster for PPO heated at 43 than at 33 or 38-degrees-C. Inactivatio n kinetics revealed PPO was more labile to CO2 and heat in the range 3 3-43-degrees-C than to heat alone. Kinetic data also revealed that CO2 , in addition to pH changes. was involved in the loss of PPO activity. Studies using gel electrophoresis showed no differences in protein pa tterns and isoelectric point between CO2-treated and non-treated contr ol. The pH of CO2-treated PPO stock solution was brought back from 5.4 to 8.0 after 6 weeks of frozen-storage and no enzyme reactivation was observed.