From the golden crust on a perfectly-baked loaf, to a crispy, crunchy potato chip - do you ever wonder why food that's been browned or charred, can smell, taste and look so good? It's one of cooking's most important flavour secrets. But it's now at the centre of a battle between health campaigners and the European food industry. The BBC’s Mike Johnson follows the story of browned and burnt food from an unexpected discovery in Paris 100 years ago to a state-of-the-art food testing laboratory in the UK, picking up some tips at a London cookery school along the way.

(Picture: Unhappy burnt toast Credit: Thinkstock)