The Intracellular Location of Particulate‐Bound Polyphenol Oxidase in Avocado Mesocarp

Polyphenol oxidase of avocado mesocarp exists in a supernatant and a participate fraction. Isolation conditions were sought where maximal polyphenol oxidase activity could be retained in the particulate fraction. More polyphenol oxidase was associated with the 270–2000 g pellet than with the 2000–12,000 g pellet. Analysis of the particulate polyphenol oxidase on linear sucrose density gradient revealed two relatively heavy peaks. The data showed that the major part of polyphenol oxidase was not a constituent of chloroplasts, chromoplasts or mitochondria. The closeness of the positions of polyphenol oxidase and of catalase in both the green and the yellow zones of the mesocarp established that most of the particulate polyphenol oxidase of avocado is associated with microbodies.