No, onions do not directly turn potatoes green. However, they indirectly contribute to potatoes potentially turning green.
Here's a breakdown:
- The Role of Ethylene Gas: Onions release ethylene gas as they ripen.
- Potatoes and Ethylene: Ethylene gas accelerates the ripening (and eventual spoiling) of potatoes.
- Greening and Sprouting: This accelerated ripening process can cause potatoes to sprout and develop a green tint under the skin.
- Solanine Production: The green color indicates the presence of solanine, a toxic alkaloid. Solanine production is stimulated by light, damage, and higher temperatures, but ethylene can hasten these processes.
- The Real Culprit: It's important to note that light exposure is the main driver of greening. So even without onions present, potatoes exposed to light will turn green. Onions just speed up the process if potatoes are already vulnerable.
- Separation is Key: Therefore, storing onions and potatoes together is not recommended because the ethylene released by the onions promotes faster ripening and potential greening of the potatoes.
In summary, while onions don't directly cause the greening, the ethylene they release accelerates ripening, increasing the likelihood of greening and sprouting, especially when potatoes are exposed to light. It's the increased exposure time and faster rate of ripening that makes it more likely for light to affect the potatoes and cause them to turn green.
