Polyphenol oxidase (PPO) was extracted from Anamur banana, grown in Turkey, and its characteristics were studied. The optimum temperature for banana PPO activity was found to be 30 degrees C. The pH-activity optimum was 7.0. From the thermal inactivation studies, in the range 60-75 degrees C, the half-life values of the enzyme ranged from 7.3 to 85.6 min. The activation energy (E.) and Z values were calculated to be 155 U mol(-1) and 14.2 degrees C, respectively. K-m and V-max values were 8.5 mM and 0.754 OD410 min(-1), respectively. Of the inhibitors tested, ascorbic acid and sodium metabisulphite were the most effective. (c) 2005 Elsevier Ltd. All rights reserved.