They say you eat with the eyes. But we now know that smell, texture, temperature, colour and even atmosphere - down to the background music - influence how we perceive flavour.As anyone who has lost their sense of taste will know, flavourless food is dull and monochrome - it is flavour that brings food into full technicolour life. Yet it's not always easy to make something tasty; the secrets to flavour can baffle chefs and scientists alike.Food science expert Dr Stuart Farrimond explores major flavour categories such as salt, acid and heat (from chillies) and how they interact, and profiles all the major foods from individual fruit, veg, herbs and spices to the building blocks such as rice and wheat that give us stapes like bread, pasta, and noodles. With pairing notes for every ingredient, you'll soon be inventing new recipes.