Why is ketchup so delicious? Science answers the big food questions

What's good, what's bad and why - five food questions answered by consultant cardiologist Ali Khavandi and science writer Dara Mohammadi

Whether you're a dolloper or a Jackson Pollocker, a plate of chips just isn't the same without a good squirt of ketchup. But why does it make chips taste so much better? It's the same reason Iberico ham is more moreish than the boiled stuff and why a sprinkle of parmesan makes a bowl of pasta that much fresher. The answer is the Japanese word for "savoury" or "deliciousness", the fifth and most elusive of tastes: umami.