Ethylene and ripening
Plants make ethylene, a gas that tells fruit to ripen. Starch turns to sugar, the flesh softens, the color shifts. Ripe bananas give off a lot of it, so a hard avocado in a paper bag with one ripens faster.
Cold slows ripening
Bananas, avocados, peaches, pears and tomatoes keep ripening after harvest. Once they're ripe, the fridge slows things down. Apples give off lots of ethylene, so keep them away from broccoli and leafy greens, which yellow faster near it.
Test yourself
Questions from the interactive lesson, with the answer and the why.
Your avocado is rock hard and you need it soon. What helps most?
Put it in a paper bag with a ripe banana. The bag traps the banana's ethylene around the avocado and speeds ripening.
True or false: Strawberries keep ripening and get sweeter on the counter after they are picked.
False. Strawberries don't ripen further once picked, so buy them fully ripe.
Fill the blank: Ethylene is a ___ that fruit release to trigger ripening.
Ethylene is a gas that fruit release to trigger ripening. Ethylene is a gas, so it drifts through the air and a bag can trap it.
What went wrong? You store apples in the same drawer as broccoli. The broccoli yellows within days.
Apples release ethylene, which speeds yellowing. Ethylene speeds the breakdown of green pigment in vegetables.
Hard, pale tomatoes from the store need to soften. Where should you keep them?
The counter, where they keep ripening. Tomatoes keep ripening after harvest at room temperature.
