Answer:
A colorless odorless gas evolves
Step-by-step explanation:
Orange juice is highly acidic. Unripe orange juice is even more acidic! As a result of this, unripe orange juice irritate the digestive tract.
We know that metals that are high up in the activity series evolves hydrogen gas when in contact with acids.
Hence, given the low pH of unripe orange juice, zinc or aluminium will evolve colorless odorless hydrogen gas after some minutes.