Mark via email from Malta asked:
What's actually happening when you fry food?
Its called the Maillard reaction after a French chemist Louis Camille Maillard. This is a chemical reaction between carbohydrate groups (that's sugars largely) and protein or amino-acids (those are the building blocks of proteins). It takes place at around 148 degrees and when these sugar groups lock on to the amino-acid groups they form these nice, brown caramelised substances which taste great – that's the nice aroma you get from cooking. As it happens at 148 degrees – that's 48 degrees hotter than water boils at – that's why you get a very different consistency and taste and texture to fried food compared to boiled.