Question

11. An avocado doesn't begin to brown until after it is cut open. List two reasons why this is the case.

12. what does microwaving avocado pulp do to the PPO enzyme?

13. microwaving avocado keeps the pulp bright green for hours, but this is not an approach uses in the dood industry. why do you think that is?

Answer 1

Answer 1:)

1. The flesh of the open avocado reacts with oxygen in the air that turns it to brown. Avocado contains polyphenols that react with the oxygen of the air under the presence of polyphenol oxidase enzyme (PPO) and make 1,2-Benzoquinone, which converts into melanin that is brown in color. Therefore, to prevent browning, don’t cut avocado to be open for a long time.
2. If any method is applied to prevent direct air contact to the open avocado, it can prevent browning. For example, applying olive oil over the flesh of the avocado prevents air contact and hence the browning.

Answer 2:)

Microwaves penetrate the peels and enter into the pulp of the avocado. The microwaves are energetic and increase the temperature inside the fruit. It denatures the PPO enzyme.

Answer 3:)

Microwaving fruits kill their natural non-harmful ingredients too. Therefore, the food industry does not support the microwaving of fruits.