DEVELOPMENT AND DISTRIBUTION OF ACTINIDIN IN KIWIFRUIT (ACTINIDIA CHINENSIS) AND ITS PARTIAL CHARACTERIZATION

The actinidin activity in kiwifruit increased 3-fold after 3 weeks postharvest ripening at 5°C with a 15% decrease in specific activity. Actinidin activity is highest in the pulp of ripe fruit at 27,600 U/kg fruit. The thiol protease actinidin from kiwifruit was extracted and purified 26-fold to a specific activity of 57 U/mg with Km= 91 μM and kcat= 101 s−1 towards N-α-CBZ-lysine p-nitrophenyl ester at pH 6.0 and 25°C.