Genetically-Engineered Non-Browning Bananas

Brown, over-ripe bananas often end up as waste, despite being edible. Scientists have developed a new genetically-engineered banana with a longer shelf-life, reducing browning. This was developed by Tropic, a UK-based biotech company.

Features of the New Banana

• Remains fresh and yellow for 12 hours after peeling.
• Less likely to brown when bumped during harvesting and transportation.

Why Do Bananas Turn Brown?

Bananas undergo a colorful life cycle from green to yellow and eventually to brown due to ripening, which is driven by the hormone ethylene.

• Bananas produce a lot of ethylene, continuing even after being harvested.
• Contact with ethylene activates genes linked to the production of the enzyme polyphenol oxidase (PPO).
• PPO in contact with oxygen breaks down yellow pigment, turning the banana brown.
• Bruising increases ethylene production, accelerating browning.

Production of Non-Browning Bananas

The company modified banana genes to disable PPO production, preventing browning without affecting ripening.

• The same technique was used in Arctic apples by Okanagan Specialty Fruits Inc., the first genetically engineered fruits approved for US commercial sale in 2017.
• Blocking PPO production works in other fruits like tomatoes, melons, kiwifruits, and mushrooms.

Significance of Non-Browning Bananas

• Bananas are extremely perishable, with approximately 50% of the crop wasted annually.
• A 2017 UK survey reports that 1.4 million edible bananas are discarded daily in Britain.
• This waste is financially wasteful and environmentally harmful, contributing to greenhouse gas emissions.
• Preventing browning reduces food waste, potentially cutting CO2 emissions equivalent to removing 2 million passenger vehicles from the road each year.