Cooking is chemistry Lesson 10 of the chemistry course of Mova's primary school: 17 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 Every kitchen is a chemistry lab: heat, acid and water change food into new substances with new tastes, smells and textures. 1 Fry a piece of meat and the outside turns brown and smells delicious, because sugars and proteins react and make hundreds of new flavour molecules. 2 Some changes are about water: popcorn bursts when water inside turns to steam, and rice swells as it soaks water into its starch. 3 Others are about proteins: boiling sets an egg, and even lemon juice can change the surface of meat or fish without any heat. 4 Knowing the chemistry also keeps you safe: hot caramel, metal in the microwave and old rice all have rules for good reasons. 5 Egg white sets at a lower temperature than the yolk, so a 4-minute egg has a runny yolk and a 10-minute egg a hard one. 6 An over-boiled egg can get a greenish ring around the yolk, where iron from the yolk joins sulphur from the white. 7 Browning of meat, toast and fried food is the Maillard reaction between sugars and proteins at high heat; boiled meat does not brown because water stays at about 100 °C. 8 Caramel is sugar broken down by strong heat into new substances; hot caramel is much hotter than boiling water and sticks to skin. 9 Popcorn pops because water inside each kernel turns to steam until the hard shell bursts; dried-out kernels pop badly. 10 Jelly sets because gelatine molecules form a loose net that traps water; fresh pineapple contains a substance that cuts gelatine and stops it setting. 11 Baking powder contains a dry acid and baking soda that react when wet and warm, making carbon dioxide bubbles; too much makes food taste soapy and bitter. 12 Slow cooking breaks down the sharp chemicals in onions and lets their sugars brown, so they turn soft and sweet. 13 The chemicals that make you cry are made only when an onion is cut. 14 Acid such as lemon or lime juice unfolds proteins as heat does; fish soaked in lime juice turns white but has not been heated. 15 Microwaves make water molecules wiggle very fast, which heats the food, often unevenly, so stirring halfway mixes hot and cooler parts; metal and foil must never go in a microwave because they can spark. 16 Rice softens and swells as it soaks up water into its starch; leftover rice should be cooled quickly and kept in the fridge, because some germs grow in it fast at room temperature. ← previous Changes you can undo and changes you can'tnext → The candle and what burning is↑ back to Chemistry This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/chemistry/10-cooking-is-chemistry/