Science Buddies: "Ask an Expert"

Hello,


We were wondering why do cold temperatures cause the ripening process to slow down in bananas?

Hi cleocurtis,

Interesting question! I'm not sure if you're planning to explore this for a project, since I recall that you were working on something else in another thread. However, I'm also curious about how the ripening process slows down, so I did a little research. It turns out that while the banana peels may turn brown or even black, the fruit inside is actually well reserved and firmer at cool temperatures. There's an enzyme in the banana, called polyphenyl oxidase, that better polymerizes phenols into polyphenols (think melanin and pigmentation, but for banana skin that darkens in color) under cooler conditions, i.e. refrigeration. Meanwhile, the banana does not get as squishy as it would at regular temperature since enzymes that decompose starch into sugar don't work as well at lower temperatures. Notice that the role of enzymes is super important in the ripening process!