What Makes Fruit Mealy?

What Makes Fruit Mealy?

March 6, 2020 100 By William Morgan


[ intro ] Everyone knows the sadness of biting into
a fresh piece of fruit only to find the inside is dry and mealy. It happens to lots of produce: peaches, watermelons, tomatoes, you name it. Some of the worst offenders are apples, like those shiny Red Delicious that are beautiful on the outside and all grainy when you take a bite. But these fruits aren’t /inherently/ terrible. They can start off yummy, and /become/ grainy. And a lot of the problem has to do with the
way they’re stored. When ripe apples are stored at cool temperatures, like inside your fridge, the cells making up the flesh of the fruit unstick from one another. But the tough outer walls of these cells stay
strong, so when you take a bite, they don’t break apart and release any juice. So instead of a burst of flavor, you just get that mealy texture. That gets worse as the apple dries out. Without moisture, the cells shrivel— and biting into those shriveled cells is like trying to pop a deflated balloon. The cells are less likely to burst and release
their flavor. And the more mature an apple is, the more it dries out. Plus, the cold air inside a refrigerator speeds
up the drying process, since it holds less moisture than warmer air. So research suggests that if you want to save
an apple for a few weeks, your best bet is to pop it in the fridge right
away, before it becomes /too/ mature. But the same rule doesn’t apply to all potentially-mealy
fruits. Soft fruits, like peaches and nectarines, can become mealy if you refrigerate them /too
soon/. That’s because their mealy texture is tied to the breakdown of a substance called
pectin. Pectin is a carbohydrate in cell walls that
fruit generates as it ripens. It strengthens cell walls and makes them stick together. But pectin can dissolve in water. And over time, as it dissolves, the cell walls lose their strength. In some fruits, pectin doesn’t /just/ dissolve,
either— it also gets broken into pieces by enzymes. And that’s a good thing. Under normal conditions, the cell walls weaken through these processes, and the fruit becomes nice and soft. When you bite into it, the cell walls burst and release their juice. Like a proper fruit. But as soon as you stick these fruits in the
fridge, that natural process starts to veer off track. In general, low temperatures slow down chemical
reactions, so if you keep fruit cold, its pectin molecules break down less. And /that/ means the cell walls hold up when
you bite into them, so whole cells break apart, rather than bursting. And you get a sad, mealy mouthful. But not all fruits will come out of the fridge
equally pathetic. Different kinds have different compounds attached to the pectin molecule, so they often ripen differently. And as a result, they /also/ react differently
to refrigeration. Still, as a general rule, fruits that continue to soften after they’re
harvested— like peaches, nectarines, cantaloupe, and
tomatoes— should only be refrigerated /after/ they’re
fully ripened if you want to avoid that gross, grainy texture. Unfortunately, you can’t always know what happened to your
fruit before it got to the store. And from the outside, it’s impossible to tell which fruit already
has a mealy texture. But you can make sure it’s not your fault
that it becomes mealy by storing it at the right time. Thanks for watching this episode of SciShow! If you liked this episode and you want to learn about another reason
we end up with disappointing fruit, you might be interested in this video about
why apples turn brown. You can watch that one next! [ outro ]