Fruit Ripening Science and Speed Tips | Generated by AI
Question: Why do bananas and mangoes turn from green to yellow after some days when received green, and how can we speed up this process?
Answer:
Both bananas and mangoes are climacteric fruits, meaning they continue to ripen after being harvested. The color change from green to yellow happens due to a natural plant hormone called ethylene gas.
Why the color changes from green to yellow
- The green color in unripe bananas and mangoes comes from chlorophyll in the peel (the same pigment that makes leaves green).
- As the fruit ripens, ethylene triggers the breakdown of chlorophyll.
- Once chlorophyll disappears, underlying yellow/orange pigments (mainly carotenoids) become visible → the peel turns yellow.
- At the same time, inside the fruit:
- Starch converts to sugar (making it sweeter)
- The texture softens
- Aroma develops
Bananas produce quite a lot of ethylene themselves (especially from the stem), so one banana can speed up ripening of the whole bunch. Mangoes also produce ethylene, but usually in smaller amounts compared to bananas.
This is why green bananas or mangoes can ripen on your counter without being attached to the plant anymore — they use their own stored energy and produce ethylene to drive the process.
How to speed up the ripening process
The most effective and safe home method is to trap the ethylene gas around the fruit:
- Paper bag method (best & most recommended)
- Put the green bananas or mangoes in a brown paper bag (or any paper bag).
- Fold the top closed to trap the gas (do not use a plastic bag — it traps too much moisture and can cause mold/rot).
- Leave at room temperature (ideally 20–25°C / 68–77°F).
- For fastest results: add 1–2 already ripe bananas or apples (they produce much more ethylene → acts like a “ripening booster”).
- Check every 12–24 hours. Usually takes 1–3 days depending on how green they started.
- Warmer location
- Place them in the warmest spot in your house (but not in direct sunlight or near a heater).
- Higher temperature (around 24–28°C) speeds ethylene production and action.
- Other quick tricks (mostly for bananas)
- For baking/cooking only (not eating fresh): oven method (bake whole at ~180°C/350°F until peel is black — 15–30 min) or microwave (short bursts) — this forces starch-to-sugar conversion fast, but changes texture/flavor.
- These heat methods do not produce real natural ripening — they are shortcuts for recipes needing very ripe bananas.
Avoid: Putting in fridge while still green — low temperature slows or stops ripening and can prevent full yellow color/sweetness later.
References:
- Why Do Bananas Change To Yellow When Ripening?
- How to Ripen Fruit Fast: Tips to Soften Mangoes & More
- How do I ripen a Mango?
- Ethylene and the Regulation of Fruit Ripening