MadSci Network: Biochemistry |
The reason that foods cook differently in oil than in water is mostly due to one specific property -- the boiling point. Water can't get hotter than 212 degrees F; when it reaches that temperature, it starts to boil, and won't get any hotter. Oils, on the other hand, can reach much higher temperatures. Safflower oil, for example, can be heated up to almost 500 degrees F! So why the food browns is mostly because the heat from a higher temperature liquid doesn't diffuse into the food as fast, and just because it's hotter. As a slower example, think about cooking a turkey in the oven. If you set the heat moderately low, say at 350 degrees, it will take a long time to cook, but when the outside is done, the inside will be too, because the heat has had time to diffuse in from the surface. But if you set the heat high, say at 500 degrees, the outside will get burned before the inside is done. That's how frech fries can be crunchy on the outside and tender in the middle! It's all temperature.
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