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Why does a cut apple turn brown?

Slicing an apple changes more than its shape. Disrupted cells allow an enzyme, compounds in the fruit, and oxygen to interact, producing the familiar brown color at the cut surface.

3–5 min

Questions you could explore

  • What changes when the tissue is cut?
  • Why is color alone an incomplete test of food safety?

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Food

Why bread dough rises

The holes in a slice of bread are a record of what happened inside the dough. In ordinary yeast-raised wheat bread, making gas is only part of the story: the dough also has to hold it.

3–5 min

Why bread dough rises

Food3–5 minThe holes in a slice of bread are a record of what happened inside the dough. In ordinary yeast-raised wheat bread, making gas is only part of the story: the dough also has to hold it.

Food

How does milk become yogurt?

Yogurt begins with milk, but its tang and texture develop as starter bacteria change the mixture. Their use of milk sugar and the resulting acidity connect the microbial activity with what ends up on the spoon.

3–5 min

How does milk become yogurt?

Food3–5 minYogurt begins with milk, but its tang and texture develop as starter bacteria change the mixture. Their use of milk sugar and the resulting acidity connect the microbial activity with what ends up on the spoon.

Food

How does mayonnaise keep oil and water together?

Oil and water separate readily, yet mayonnaise can hold them in a thick mixture. The oil remains in tiny droplets rather than dissolving, and emulsifying components help those droplets stay dispersed.

3–5 min

How does mayonnaise keep oil and water together?

Food3–5 minOil and water separate readily, yet mayonnaise can hold them in a thick mixture. The oil remains in tiny droplets rather than dissolving, and emulsifying components help those droplets stay dispersed.

Why does a cut apple turn brown? | Speech Topic | speaking.app