INHIBITION OF SURFACE BROWNING, CUT AVOCADO

Browning prevention of avocado halves using polyphenol oxidase (PPO) inhibitors along with sulfites was investigated. Browning inhibitiors were selected on the basis of the inhibition of a crude extract of avocado PPO. The most effective inhibitors were ascorbic acid and sodium sulfite, these compounds plus citric acid were mixed to get an inhibitory solution. In vivo experiments were performed on avocado halves by measuring Hunter color values after 15 days' storage to test the potential of solutions to prevent browning. Results showed that immersion in solutions along with refrigerated storage was needed to get an inhibitory effect. Color preservation was not due to oxygen exclusion nor to low pH and sulfite was unnecessary. The best treatment was the storage of avocado halves in a 1% ascorbic acid/1 % citric acid solution at pH 5 and 7C.